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You've likely heard that the moon is responsible for tides on Earth, but have you ever actually thought about why? While the moon has the biggest effect on Earth's tides, the sun and the ocean's shape also have effects that increase or decrease the tide. The effects of the moon on Earth's tides are called moon tides. Moon tides are the main focus of this article.&nbsp;



<figure class="wp-block-image size-large is-style-default"><img src="https://www.earth.com/wp-content/uploads/2022/09/moon_10big_stock-1024x683.jpg" alt="" class="wp-image-1912202"/></figure>



<h2 id="h-moon-tides-from-the-moon-orbiting-the-earth">Moon Tides from the Moon Orbiting the Earth</h2>



Everything in space exerts gravity on everything else. Since the moon is the closest celestial body to Earth, it exerts the greatest force on the Earth's oceans. The force of the&nbsp;moon's gravity pulls both the Earth and the water on Earth's surface closer to the moon. When water is pulled towards the moon the tide goes up. Whatever part of the Earth is closest to the moon experiences the most intense lunar gravity, and therefore the most intense moon tide. But the gravitational pull of the moon doesn't stop there! The moon also pulls the Earth slightly towards it, pulling the side of the Earth closest to the moon with the most force, and the side of the Earth furthest away from the moon with the least amount of force. The water on the side of the Earth furthest from the moon experiences the least amount of lunar gravity.&nbsp;



There are two high tides each day. As the Earth completes its 24-hour, day-long rotation, the side of the Earth which is closest to the moon constantly changes. This is why a high tide happens every 24 hours (actually, it's 24 hours and 50 minutes, but more on that later).



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/02/shutterstock_2064415841.jpg" alt="" class="wp-image-1904626"/><figcaption>A graph shows the height of the tide over a 24 hour period. <a href="https://www.shutterstock.com/g/pijitra-phomkham">PIJITRA PHOMKHAM</a>/<a href="http://shutterstock.com">Shutterstock</a>.</figcaption></figure>



<h3 id="h-the-second-high-tide">The Second High Tide</h3>



Each day there is a second, lesser high tide. This second high tide occurs on the side of Earth furthest from the moon. Initially, that doesn't seem to make much sense, right?



While the moon pulls all the water on Earth towards it, it also pulls the Earth slightly towards the moon. Since the water furthest from the moon experiences little lunar gravity, it is being pulled less than the rest of the Earth. This means that, because the water farthest from the moon gets pulled the least, the water is higher compared to the Earth.



Additionally, as the Earth and moon spin around each other, the water furthest from the moon experiences centripetal force. This means that the water furthest from the moon is being spun as the Earth travels around the moon with more force than the water closest to the moon. Together, the centripetal force and the difference in gravity between the sides of the Earth facing the moon create a tidal bulge on the opposite side of Earth from the moon.



<h3 id="h-low-moon-tides">Low Moon Tides</h3>



The areas of the ocean halfway between the side of the Earth closest to the moon and the side furthest away experience low tides. These low tides occur because neither the lunar gravity is particularly strong, nor the effect from the centrifugal force. Low tides occur halfway between high tides, or about every six hours.



This is how the moon tides work on a day-long period.



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/02/shutterstock_1038196303-1024x929.jpg" alt="" class="wp-image-1904629"/><figcaption>A diagram demonstrating how the sun interacts with the moon to make spring and neap tides. <a href="https://www.shutterstock.com/g/marina-durante">Anna L. e Marina Durante</a>/<a href="http://shutterstock.com/">Shutterstock</a>.</figcaption></figure>



<h2 id="h-phases-of-the-moon-impact-moon-tides-sort-of">Phases of the&nbsp;Moon&nbsp;Impact Moon Tides (Sort Of)</h2>



Moon tides also depend on a month-long time scale. When the moon is full and new, Earth experiences spring tides. When the moon is half full (a waxing or waning gibbous), the Earth experiences neap tides. Neap tides are weak, meaning the difference between the high and low tides is small. Spring tides, on the other hand, are strong. Spring tides and neap tides, while correlated with the moon, are technically not moon tides; they are solar tides.&nbsp;



The sun also exerts gravity on Earth and contributes about half as much to the tides as the moon. The effect of the sun on tides is called solar tides. Acting together, the moon and sun create large tidal forces.



When the moon is new, it is between the Earth and the sun. This means the lined-up forces from the moon and the sun add together to create an extra strong pull. When the moon is full, it is on the opposite side of the Earth from the sun. Since the sun and moon each pull on an opposite side of Earth, this also creates spring tides.



Bonus fun fact: When three celestial bodies are lined up they are in 'syzygy.' Can you believe a word like that exists?



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/09/moon_neap-tide_nasa.gif" alt="" class="wp-image-1912203"/></figure>



When the moon is half full, the moon and sun make a right&nbsp;angle, with the Earth in the middle. In this position, the moon tides and sun tides interfere with each other, creating small neap tides.&nbsp;



<h3 id="h-the-moon-s-orbital-period-impacts-moon-tides">The Moon's Orbital Period Impacts Moon Tides</h3>



It takes the moon 29.5 days to completely orbit the Earth or to go from full moon to full moon. This is called the moon's "synodic" or lunar&nbsp;month. Kind of like how the hour and second hand on a clock move at different rates, the moon slightly outpaces the Earth's 24-hour rotation. This means that the moon will be in slightly further along in the sky once the Earth does its complete 24-hour rotation. If you divide 24 hours by 29.5 days (the moon's orbit around Earth), you get about 50 minutes. This is why lunar tides are 24 hours 50 minutes and why the time of the high tide gets later by 50 minutes every day. 



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/02/shutterstock_120511270.jpg" alt="" class="wp-image-1904631"/><figcaption>This diagram demonstrates a new moon approximately at the apogee and the full moon at the perigee of the moon's orbit. <a href="https://www.shutterstock.com/g/redsapphire">Redsapphire</a>/<a href="http://shutterstock.com/">Shutterstock</a>.</figcaption></figure>



<h2 id="h-the-shape-of-the-moon-s-orbit-impacts-moon-tides">The Shape of the Moon's Orbit Impacts Moon Tides</h2>



Not only does the moon orbit around Earth, but the moon also moves through its own, elliptical orbit. When the moon is closest to Earth in its ellipse, it exerts more gravity and, therefore, higher tides. This position is called the perigee. In contrast, when the moon is further away from Earth in its elliptical orbit, tides are unusually small. This position is called the apogee.



This elliptical orbit does not match the moon's&nbsp;orbit around the Earth. As mentioned above, the moon's orbit around the Earth, or synodic month, is 29.5 days. The elliptical orbit, or anomalistic month, is 27.5 days. This means that each time the moon is full, it will be in a slightly different place within its elliptical orbit.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/02/shutterstock_1586532991.jpg" alt="" class="wp-image-1904635"/><figcaption>This diagram drastically accentuates the elliptical nature of the moon's orbit. The moon's orbit is essentially round with just a tiny oval squish to it. <a href="https://www.shutterstock.com/g/renklerinkafasi">renklerin kafasi</a>/<a href="http://shutterstock.com/">Shutterstock</a>.</figcaption></figure>



When the moon is full or new and in its perigee, the moon is a&nbsp;<a href="https://www.earth.com/news/super-worm-moon-tonight/" target="_blank" rel="noreferrer noopener">supermoon</a>. The gravity of the combined sun and moon, plus the closer-than-usual position of the moon make for exceptionally high tides.&nbsp;



<h3 id="h-the-earth-s-orbit-is-also-elliptical">The Earth's Orbit is Also Elliptical</h3>



Interestingly, the Earth also has a slightly elliptical orbit around the sun. Similarly to the moon's orbit, the tides are larger when the Earth is closest to the sun, around the New Year. The tides are smaller in early July, when the Earth is furthest from the sun.&nbsp;



<h3 id="h-the-moon-has-an-even-longer-orbit">The Moon Has An Even Longer Orbit</h3>



The moon also has a wobble in its orbit that changes the magnitude of tides on 18.5 year scale. This wobble will make tides higher than usual&nbsp;<a href="https://www.earth.com/news/the-moons-wobbles-will-cause-a-surge-in-coastal-flooding/" target="_blank" rel="noreferrer noopener">in the 2030s</a>.&nbsp;



<h2 id="h-the-shape-of-the-continents-and-ocean-floor">The Shape of the Continents and Ocean Floor</h2>



Not all tides are created equal. In the Bay of Fundy in Canada, the difference between high and low tide is&nbsp;<a href="https://bayoffundytourism.com/worlds-highest-tides/times/" target="_blank" rel="noreferrer noopener">40-50 feet</a>. Many coastal areas only have a few feet of difference between high and low tide.



While not the scope of this article, the shape of Earth's oceans, coastline, and ocean floor all contribute to the vast differences between tides in different coastal areas.



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/02/shutterstock_2049610358.jpg" alt="" class="wp-image-1904636"/><figcaption>This line of seaweed was left when the high tide retreated back down the beach. <a href="https://www.shutterstock.com/g/elmar-langle">Elmar Langle</a>/<a href="http://shutterstock.com/">Shutterstock</a>.</figcaption></figure>



<h2 id="h-combining-the-factors-to-make-the-biggest-moon-tide">Combining the Factors to Make the Biggest Moon Tide</h2>



The highest tide would happen when many of these factors occurred at the same time. First, the moon must be a&nbsp;<a rel="noreferrer noopener" href="https://www.earth.com/news/tonights-super-moon-coincides-with-a-total-lunar-eclipse/" target="_blank">supermoon</a>, where the moon is new and at its perigee. If the super moon this happened around the New Year, when Earth is closest to the sun, it would be a massive tide. If this combined with a storm, heightened sea levels from climate change, and the moon's 18.5 year wobble, it would likely be the highest water level possible. Tides such as this pose great issues to low-lying coastal areas, which are prone to&nbsp;<a rel="noreferrer noopener" href="https://www.earth.com/news/global-warming-will-greatly-increase-flood-related-displacement/" target="_blank">devastating tidal flooding</a>.&nbsp;



Moon tides have lead to the evolution of special tidal critters and all sorts of interesting animal behavior. Next time you are at the beach make sure to pay attention to the moon, how the time and height of the tides change from day to day, and how the birds, and fish use the tides to their advantage. 



Check us out on&nbsp;<a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

What are Moon Tides?

You've likely heard that the moon is responsible for tides...

Deep-sea,Stingray

70% of the world's surface is the ocean - and much to the horror of humans through the millennia, scary sea monsters are actually a real thing. They prowl the vast waters of our globe and emerge with terrifying results in stories - and real life.&nbsp;



From the Atlantic to the Pacific oceans, from the North to the coast of New Zealand, there are fascinating sea creatures that strike fear into the hearts of the bravest explorers and threaten the most unsuspecting coastal tourist. At the same time, these scariest sea animals are wonderful, enchanting, <a href="https://www.earth.com/news/deep-sea-vents-are-favorable-to-the-formation-of-life/" target="_blank" rel="noreferrer noopener">living examples of evolution</a>, adaptive behaviors, and thrilling possibilities within nature.&nbsp;



Perhaps that's why they play such a massive role in our collective imaginations as well: the Kraken of Nordic sea lore, the loch ness monster of Scotland, the Lukwata sea monster of Uganda. The list of fables, legends, and sea shanties is as deep as the deep-sea waters where some monstrous animals swim. Science is just beginning to catch up and we can look to organizations like NOAA (National Oceanic and Atmospheric Administration) and MBARI (Monterey Bay Aquarium Research Institute) and others for emerging information on the truth behind the scary stories.&nbsp;



So let's dive in: today we'll look at the ecosystem of the ocean - the playground and habitat of an estimated one million animal species - and rip through some flash-points of the scariest swimming creatures among the masses. We'll also look at the ways in which the changing, warming oceans make even the most fearsome creatures vulnerable to disturbance and possible extinction. Scary stories abound!&nbsp;



<h2 id="h-an-ecosystem-of-monstrous-proportions">An Ecosystem Of Monstrous Proportions</h2>



When you think about it, the ocean itself is a bit of a monster - a living, breathing system of giant proportions.&nbsp;



For example, most life on earth is aquatic. Less than 5% of the oceans have been explored. The longest Mountain range is underwater. <a rel="noreferrer noopener" href="https://kealakai.byuh.edu/twenty-fun-facts-about-the-ocean" target="_blank">70% of the world's oxygen</a> - a fiendish amount - is produced by the ocean. The pressure on the seafloor will crush you. 90% of the Earth's volcanic activity happens in the ocean and the <a href="https://earth.google.com/web/@-18.57813014,147.57013641,-41.94434357a,0d,60y,201.23400896h,83.69613794t,0r/data=ClUaUxJNCiUweDZiZGYxNDQ2ODIyYzcxM2I6MHgxOTJhNTc0MTM2ODMzY2RhGXLEtTV9STLAITRUe8dfdmJAKhJHcmVhdCBCYXJyaWVyIFJlZWYYASABIjAKLEFGMVFpcE5ZdE5CTzd6bi01bGxXVzNEbGxTbGtxRHAxS0FTaGM4Q1JvZWR2EAU">great barrier reef</a> of Australia is so massive it can be seen from the moon.&nbsp;



The stats continue on in epic, sublime ways: the largest blue whale on record is as long as an 11-story building. The rounded sound ever recorded was of an iceberg falling into the ocean - and could be <a rel="noreferrer noopener" href="https://kealakai.byuh.edu/twenty-fun-facts-about-the-ocean" target="_blank">heard 3,000 miles away.</a> The ocean exists as a living fossil of itself, providing important clues and records of sea animals what has occurred on planet earth. It contains limitless secrets for us to slowly piece together, like a salty sea foam puzzle.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_1137771782.jpg" alt="" class="wp-image-1900841"/><figcaption><a href="https://www.shutterstock.com/g/posteriori">posteriori</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-some-specific-scary-sea-monsters">Some Specific Scary Sea Monsters</h2>



There are plenty of secrets of the monstrous seven seas that we have yet to understand. But there are plenty of real-life sightings to send a shiver-of-a-jellyfish sting up your spine.&nbsp; The depths of the ocean are where mysticism meets horror movies - and the surface is by no means safe, either.&nbsp; Read on for a thoroughly-inconclusive list.&nbsp;



<h3 id="h-box-jellyfish">Box Jellyfish&nbsp;</h3>



Box Jelly is especially scary because to encounter a box tentacle is usually a death sentence for a human being. Named for their shape, they are considered the <a href="https://oceanservice.noaa.gov/facts/box-jellyfish.html" target="_blank" rel="noreferrer noopener">most venomous animal</a> in the ocean according to NOAA.&nbsp;



Their tentacles are loaded with poison darts known as nematocysts. People and animals that encounter these booby-trap-laden strings can become paralyzed, have heart failure, and die within minutes. There are 50 or so species of box jellyfish, and only a couple have the venom count to kill people. Those species are found in the Ind-Pacific region and Australia. Terrifyingly, they do not live in deep water but are a coastal species.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_68332459.jpg" alt="" class="wp-image-1900842"/><figcaption><a href="https://www.shutterstock.com/g/lienkie">Daleen Loest</a>/Shutterstock.com</figcaption></figure>



<h4 id="h-is-it-actually-dangerous">Is It Actually Dangerous?</h4>



Yes - box jellyfish live up to the hype. We often do not live up to their tentacles. Avoid these sea creatures at all costs.&nbsp;



<h3 id="h-frilled-shark">Frilled Shark</h3>



The frilled shark is what many scientists consider a "living fossil" with its strange lizard-like head, ruffled throat, <a rel="noreferrer noopener" href="http://www.elasmo-research.org/education/ecology/deepsea-frilled_shark.htm" target="_blank">long body, and tiny fins.</a> It definitely looks a lot like how a "sea serpent" of folklore is described. While it doesn't exactly add validity to stories like the Loch Ness monster or the Midgard serpent, it does have an "enchanting beast" quality to its appearance.&nbsp;



Frilled sharks rarely swim up to surface waters. Instead, they are a species of shark that moves through various life cycles in the area of the ocean known <a rel="noreferrer noopener" href="http://www.elasmo-research.org/education/ecology/deepsea-frilled_shark.htm" target="_blank">as the "twilight zone". </a>Want to take a look at another "living fossil" of the <a rel="noreferrer noopener" href="https://www.earth.com/earthpedia-articles/everything-youve-wanted-to-know-about-deep-sea-fishing/" target="_blank">deep sea</a> with an unnerving smile? Check out the <a rel="noreferrer noopener" href="https://www.jstor.org/stable/3877998" target="_blank">Goblin Shark.</a>&nbsp;



<h4 id="h-is-it-actually-dangerous-1">Is It Actually Dangerous?</h4>



No - these sea monsters just look scary. They are active predators but pose no threat to humans.&nbsp;&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_134776526.jpg" alt="" class="wp-image-1900858"/><figcaption><a href="https://www.shutterstock.com/g/demarfa">Natursports</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-fangtooth-fish">Fangtooth Fish</h3>



Fangtooths have a look that will haunt your dreams - and will continue to inspire the art-imitates-life-forms of various installations and horror films. It has <a href="https://www.earth.com/earthpedia-articles/5-strangest-deep-sea-creatures/" target="_blank" rel="noreferrer noopener">razor-sharp teeth of terrifying lengths</a> - perfect for catching prey such as fish and crustaceans.&nbsp;



They are deep-sea swimmers along with Anglerfish. Their habitat ranges in tropical and temperate seas <a rel="noreferrer noopener" href="https://www.montereybayaquarium.org/animals/animals-a-to-z/fangtooth" target="_blank">at 1,640 to 6,561 feet deep.</a>



<h4 id="h-is-it-actually-dangerous-2">Is It Actually Dangerous?</h4>



No - these fangtooths live so deep, they pose no threat to us - just the other animals that they feast and hunt for.&nbsp;



<h3 id="h-viperfish">Viperfish&nbsp;</h3>



Another fish with an appearance that can absolutely give you nightmares is the viperfish. It's a broad title for any species of marine fish in the genus Chauliodus. These species are characterized by needle-like teeth and hinged jaws that will remind you of an underbite.&nbsp;



These are also deep-sea swimmers. Similar to other species living in the dark depths of the ocean, they lure in their prey with <a rel="noreferrer noopener" href="https://academic.oup.com/sysbio/article-abstract/1/3/113/1696037" target="_blank">light-producing organs called photophores.</a>



<h4 id="h-is-it-actually-dangerous-3">Is It Actually Dangerous?</h4>



Nope - again, these fish swim so deep that they pose no risk to us.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/Giant_squid-1-1024x921.jpg" alt="" class="wp-image-1900860"/><figcaption>Specimen of giant squid nicknamed&nbsp;Wheke&nbsp;plastinated&nbsp;from 2005 and displayed on 26&nbsp;March 2008 in the&nbsp;Grande galerie de l'Évolution&nbsp;of the&nbsp;muséum national d'histoire naturelle&nbsp;in Paris. Photo via <a href="https://en.wikipedia.org/wiki/National_Museum_of_Natural_History,_France#/media/File:Giant_squid.jpg">Wikipedia.org</a>.</figcaption></figure>



<h3 id="h-giant-squid">Giant Squid</h3>



Indeed, the giant squid is much more than a fictionalized creature in the lake on the Hogwarts School Of Witchcraft And Wizardry grounds. The giant squid is a real-life animal and the second-largest mollusc we know of in Earth's history. It is an excellent example of deep-sea gigantism, <a rel="noreferrer noopener" href="https://daily.jstor.org/why-deep-sea-creatures-get-weirdly-giant/" target="_blank">a phenomenon and zoology term</a> that describes species of animals that are significantly larger than their shallow-water cousins.&nbsp;&nbsp;



Why is this? <a href="https://www.jstor.org/stable/3838549?mag=why-deep-sea-creatures-get-weirdly-giant&amp;seq=1#metadata_info_tab_contents" target="_blank" rel="noreferrer noopener">McLain et al.</a> propose that "limited resources [in deep water] select for larger body sizes that can better withstand periods of famine or ability to cover larger distances in search of scarce prey."&nbsp;



In 2019, a giant squid sighting was documented <a rel="noreferrer noopener" href="https://www.nytimes.com/2019/06/21/science/giant-squid-cephalopod-video.html" target="_blank">on video near the Gulf of Mexico</a>, reigniting the public's fear and fascination. In this instance, the squid was only a juvenile but was still an estimated 10 feet long.&nbsp;



<h4 id="h-is-it-actually-dangerous-4">Is It Actually Dangerous?</h4>



<a href="https://www.tepapa.govt.nz/discover-collections/read-watch-play/science/colossal-squid/difference-colossal-squid-giant-squid-octopus" target="_blank" rel="noreferrer noopener">Squid and octopus</a> (giant, or otherwise) are formidable fighters. While they do not typically attack humans, they are well equipped to defend themselves if they feel threatened.



<h3 id="h-vampire-squid">Vampire Squid</h3>



A name worthy of a horror movie in and of itself, the vampire squid is indeed a real-life thing - - a sea creature that is actually quite small with an intriguing appearance. It's scientific name&nbsp; is Vampyroteuthis infernalis. It lives in tropical and temperate waters in areas identified by "extreme deep-sea conditions". It is the only known survivor of the order Vampyromorphida and is a species that produces bioluminescence.&nbsp;



The arms of this squid will <a href="http://www.thecephalopodpage.org/vsfh.php" target="_blank" rel="noreferrer noopener">regenerate if bitten or ripped off.</a> Often, the discarded limbs then act as a diversion for the vampire squid to escape. It's a defense mechanism that is equal parts scary and amazing.&nbsp;



<h4 id="h-is-it-actually-dangerous-5">Is It Actually Dangerous?</h4>



According to NOAA, vampire squids are not even slightly dangerous to humans - they simply live too deep for us to encounter them.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2022/01/shutterstock_390021130.jpg" alt="" class="wp-image-1900862"/><figcaption><a href="https://www.shutterstock.com/g/Martin+P">Martin Prochazkacz</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-great-white-shark">Great White Shark&nbsp;</h3>



One of Finding Nemo's charming villains with a soft side, the Great white shark is no stranger to our psyches. Horror stories, films, and encounters abound.&nbsp;



These monsters are a species of large mackerel shark found in the coastal waters of all major oceans. It's only predator in the wild is, occasionally, the killer whale.&nbsp;



While scientists explain that humans are not the "<a href="https://web.archive.org/web/20090426174140/http://news.nationalgeographic.com/news/2004/01/0123_040123_tvgreatwhiteshark.html" target="_blank" rel="noreferrer noopener">preferred prey</a>" of the great white shark - it's just that these creatures are curious, and are willing to take a taste test. Not a comforting thought for surfers and swimmers, to say the least.&nbsp;



Similar to the drama around bears, lions, and tigers on land, the idea of a shark attack ends up being much bigger, culturally, than the actual risk. For example, there were <a href="https://www.floridamuseum.ufl.edu/shark-attacks/yearly-worldwide-summary/" target="_blank" rel="noreferrer noopener">8 reported shark attacks in 2021</a>. For some context, over 40% of the world's human population lives in coastal areas. These attacks are exceedingly rare.&nbsp;



<h4 id="h-is-it-actually-dangerous-6">Is It Actually Dangerous?</h4>



Even if these attacks are more rare than we might realize, there's no doubt about it. Great white sharks are dangerous animals.&nbsp;



<h2 id="h-protecting-our-sea-monsters">Protecting Our Sea Monsters&nbsp;</h2>



Of course, the scariest story of all the scariest sea monster stories are the monstrous implications of human impact on our oceans, coastlines, and fragile marine ecosystems.&nbsp;



In addition to warming water and unknown impacts on deep sea migration and global currents impacting weather, there are the immediate crises that our societies must address.&nbsp;



<a href="https://oceanservice.noaa.gov/hazards/beach-dangers/" target="_blank" rel="noreferrer noopener">Contaminated water</a> from oil rigs, untreated sewage, boats, pets, broken septic systems, and fertilizers accumulate in the ocean. People become outraged when their favorite swimming beach is closed due to dangerous contamination - and yet, the companies and public industry responsibility is rarely held accountable or reformed in a sustainable way.&nbsp;



The same goes for the terrifying amounts of plastic in our oceans, in the bodies of the animals that live there, and of course, <a href="https://oceanservice.noaa.gov/hazards/beach-dangers/" target="_blank" rel="noreferrer noopener">in our own systems.&nbsp;</a>



And of course, there is a lot of conversation about the fishing industry - much overdue - and the ways in which extractive and exploitative fishing methods ravage the populations of tasty fish, <a href="https://oceanservice.noaa.gov/facts/coral-overfishing.html" target="_blank" rel="noreferrer noopener">and demolish additional species</a> habitats and behaviors in the process.&nbsp;



Scary sea creatures are impacted by all of this of course - along with the more beloved marine-dependent creatures that whole throngs of people identify with - like sea turtles, dolphins, lobsters and other crustaceans, Giant Isopods, crocodiles, and oh so many species of birds. There is an endlessly nuanced web of life that depends on healthy oceans. All of it, ourselves included, depends on our ability to shift our own species' behavior. Either we do so or we are the true monsters.



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Scary Sea Monsters That Are Actually Real

70% of the world's surface is the ocean - and...

Deep,Sea,Fishing,Reel,On,A,Boat,During,Sunrise

Deep-sea fishing sure sounds like an intense adventure to endure. And for those people who were not raised within a tradition of coastal subsistence, the learning curve around deep water can be a steep dive into the unknown. But with these deeper waters comes big fish. Plus there are buckets of fun and funds in the form of a booming tourist industry for ocean communities and beach visitors alike.&nbsp;



If you're just getting into the waters of sportfishing and charter boat day trips, there's a lot you'll want to know about the origins, techniques, and impacts around this form of fishing. And while we may not have time to cover everything you want to know about deep-sea fishing today, we'll definitely troll our way to a snapping good start.&nbsp;



<h2 id="h-origins-of-deep-sea-fishing">Origins Of Deep Sea Fishing&nbsp;</h2>



Thanks to the clues remaining in the fossil record, archeologists estimate that humans have been fishing for subsistence for at least <a href="https://www.npr.org/2010/07/05/127937070/the-human-edge-finding-our-inner-fish" target="_blank" rel="noreferrer noopener">500,000 years.</a> The first evidence we have found (so far) of deep-sea fishing is a bit more recent, however, dating back to 42,000 years ago in the <a href="https://www.science.org/content/article/when-humans-first-plied-deep-blue-sea" target="_blank" rel="noreferrer noopener">area of East Timor.</a>



For many various areas of the globe, fishing practices were (and are) integral communal practices that shaped culture and tradition through generations, shifting with technology of course, but still part of an expansive lineage of hungry and enterprising humans.&nbsp;



What started with hands and rudimentary tools evolved into various techniques. Today we have whole multi-million dollar industries around lures and rods. Plus, there are government agencies that regulate most individuals with fishing licenses. There are strict guidelines on what, when, and where we are permitted to fish. We've come a long way from where we started. You'll want to do plenty of research on the laws and practices of whatever location you plan to fish, as areas will differ.&nbsp;



<h2 id="h-dangers-of-deep-sea-fishing">Dangers Of Deep Sea Fishing</h2>



You might love deep sea fishing so much, you wish it could be your full-time job. But before you hand in the resignation papers to your desk job, it's important to note: even in our more modern era, these practices of offshore fishing are a far seagull-cry away from a relaxing sail in the bay. This is especially true when it comes to making a livelihood in these industries. Ever heard of the reality TV show "<a href="https://www.youtube.com/watch?v=CRO6H8puHF8&amp;ab_channel=Discovery" target="_blank" rel="noreferrer noopener">The Deadliest Catch</a>"?



According to a study published by BMJ Journal of Occupational and Environmental Medicine, data from the 19th century indicates high mortality rates of fishermen of the deep sea - at <a href="https://oem.bmj.com/content/28/1/27.short" target="_blank" rel="noreferrer noopener">least double that of coal miners</a> and 20 times the rate of workers in industrial manufacturing around the same time. These strikingly high numbers are still a reality due to the dangerous conditions of the sea, compounded by weak or failing vessels, negligent navigation, and excessive fatigue. Often, these fishermen worked incredibly long hours - a detriment to their boats and their lives in many cases.



<h2 id="h-a-booming-tourist-industry">A Booming Tourist Industry&nbsp;</h2>



However, making a living as an industrial deep-sea fisher is pretty different than deep-sea fishing for fun on a private charter or party boat fishing thanks to a gift certificate from a supportive family member.&nbsp;



Deep-sea fishing is a booming aspect of some coastal tourist industries. Sportfishing for a full day or half-day is a common vacation for passionate fishers from any area. Charter boats accommodate day fishing trips for groups or individuals. With the right amount of research, resources, and know-how, people can time their trips to be able to fish year-round.&nbsp;



Deep-sea fishing charters might <a href="https://www.earth.com/earthpedia-articles/what-actually-is-deep-sea-fishing/?utm_source=google&amp;utm_medium=cpc&amp;utm_campaign=14016588382&amp;utm_content=130809272808&amp;utm_term=&amp;gclid=CjwKCAjwoP6LBhBlEiwAvCcthEHAgKSID-XJR9J_O2FnZU5XAz4tqRevAVjStDzVqk86uOHQ63Is-hoCLpEQAvD_BwE" target="_blank" rel="noreferrer noopener">troll with live bait</a>, chum, pop, or jig. There are all sorts of terms and techniques. Various charters and fishing boats will utilize depending on the area and the intended fish to catch.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_577915762.jpg" alt="" class="wp-image-1897951"/><figcaption><a href="https://www.shutterstock.com/g/Go2dim">Go2dim</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-deep-sea-fish-of-interest">Deep-Sea Fish Of Interest&nbsp;</h2>



So, where to go to deep sea fish?&nbsp;



That all depends on what you hope to catch, the season you're in, and the money you have to get there.



<a href="https://www.earth.com/earthpedia-articles/what-actually-is-deep-sea-fishing/?utm_source=google&amp;utm_medium=cpc&amp;utm_campaign=14016588382&amp;utm_content=130809272808&amp;utm_term=&amp;gclid=CjwKCAjwoP6LBhBlEiwAvCcthEHAgKSID-XJR9J_O2FnZU5XAz4tqRevAVjStDzVqk86uOHQ63Is-hoCLpEQAvD_BwE" target="_blank" rel="noreferrer noopener">The west coast of North America</a> is known for yellowtail, sturgeon, albacore tuna, rockfish, sea bass, and barracuda. On the other side of the continent, popular finned catches include bluefin and yellowfin tuna, cod, striped bass, and <a href="https://www.earth.com/news/volcanic-eruption-fishing-industry/" target="_blank" rel="noreferrer noopener">mackerel</a>. The Gulf of Mexico pulls tons of tourists to the deep waters each year - where parties troll for dorado, shark, king mackerel,&nbsp; red snapper, and more. Hawaii is another popular destination for avid fisherpeople. There, lures sink in the water in hopes of snagging sea creatures such as yellowfin ahi tuna, giant blue marlin, dorado, sailfish, swordfish, <a href="https://www.earth.com/earthpedia-articles/what-actually-is-deep-sea-fishing/?utm_source=google&amp;utm_medium=cpc&amp;utm_campaign=14016588382&amp;utm_content=130809272808&amp;utm_term=&amp;gclid=CjwKCAjwoP6LBhBlEiwAvCcthEHAgKSID-XJR9J_O2FnZU5XAz4tqRevAVjStDzVqk86uOHQ63Is-hoCLpEQAvD_BwE" target="_blank" rel="noreferrer noopener">and wahoo</a>.



<h2 id="h-deep-sea-fishing-in-a-changing-climate">Deep-Sea Fishing In a Changing Climate&nbsp;</h2>



It's not all fun and games, however. And our climate arrogance is catching up to us the same way we hope to catch a delicious meal.&nbsp;



The deep-sea is one of our planet's last great wildernesses. It covers <a href="https://www.sciencedirect.com/science/article/abs/pii/S0169534702024928" target="_blank" rel="noreferrer noopener">62% of the planet</a> and drops to over 1000 meters deep in some locations. These areas are still largely unexplored. New technology reveals unknown habitats and species almost as fast as we can search. However, with this technology, comes industry and economic interest. With some much still unknown, these conflicting human impulses of curiosity and extraction are laid bare - with some <a href="https://www.sciencedirect.com/science/article/abs/pii/S0169534702024928" target="_blank" rel="noreferrer noopener">devastating consequences</a>.&nbsp;



For example, when deep-sea fishing commenced in the Northeast Atlantic in the 1970s, there has been a <a href="https://www.sciencedirect.com/science/article/pii/S0960982215009380">marked decline of commercial fish species</a>. This includes species such as <a href="https://www.fisheries.noaa.gov/new-england-mid-atlantic/endangered-species-conservation/endangered-and-threatened-species-new" target="_blank" rel="noreferrer noopener">bluefin tuna, sturgeon, and salmon. </a>Many fisheries in the deep sea have a pathetic track record in regard to sustainable practices. Even as individuals organize for change and governing bodies pass protective legislation, there are issues. We struggle to maintain the enforcement of fishing regulations and willing compliance by those working within the industry. Limits to trolling depths as well as greater incentives for sustainable practices within the industry are a good starting point.&nbsp;



<figure class="wp-block-image size-large"><img src="https://www.earth.com/wp-content/uploads/2021/11/shutterstock_251648188.jpg" alt="" class="wp-image-1897952"/><figcaption><a href="https://www.shutterstock.com/g/photonatura">Leonardo Gonzalez</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-conclusion">Conclusion&nbsp;</h2>



The deep-sea is our largest ecosystem. It's impossible to know everything about fishing there. We're learning new things about the depths of these saltwater bodies every day. We do know that many species that live in the open waters and deep seas exhibit characteristics and life patterns that are <a href="https://www.sciencedirect.com/science/article/pii/S0960982215009380" target="_blank" rel="noreferrer noopener">vulnerable to disruption and exploitation</a>.&nbsp;



As you continue to learn and explore the world of deep-sea fishing, it is critical to keep the longevity of these ecosystems in mind. We have to remember that our actions impact these amazing places. Unless we hold ourselves to a more sustainable standard, there won't be fun deep sea fishing trips - or a livable planet - in future years to come.



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Everything You've Wanted to Know About Deep-Sea Fishing

Deep-sea fishing sure sounds like an intense adventure to endure....

Angler,Fish,,Edridolychnus,Schmidti.,The,Larger,Female,Has,Two,Smaller

Secrets of the Ocean's Mysterious Mesopelagic Zone

Our oceans shape our world. They drive the weather patterns...

Waves,Of,Water,Of,The,River,And,The,Sea,Meet

Earth’s waters are constantly moving. They change form in the water cycle. They flow from the tiniest streams to the biggest rivers. Even on the stillest days in the ocean, the water is never quite static. In fact, ocean water movement can be summed up in three genres: currents, tides, and waves. Though just a thin layer on the earth’s crust, the forces both on and outside our planet treat our oceans like putty. Celestial bodies like the sun and moon push and pull the oceans as the earth hurtles through space. Similarly, the Earth’s own gravity and rotation impact oceanic movement.&nbsp;



But waves, tides, and currents are each distinct from one another depending on their temporal and physical scale along with their behavior. Here we’ve outlined the important distinctions between waves, tides, and currents.



<h2 id="h-currents">Currents</h2>



Currents are predictable and directional movements of water that persist for longer periods of time. Occurring at all ocean depths from the intertidal to the benthic zones, currents impact the earth’s climate by carrying pockets of heat around the globe.&nbsp;



<h3 id="h-creating-currents">Creating Currents</h3>



A combination of wind, sun, gravity, and the Earth’s rotation influences our planet’s currents. And all four factors are quite interconnected. Radiation from the sun creates wind. Prevailing winds create peaks and valleys in the ocean water, while gravity pulls water toward the valleys. Finally, the Earth’s rotation is the soup spoon stirring the pot to create direction.&nbsp;



<figure class="wp-block-image alignnone size-full wp-image-1893436"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_137936432.jpg" alt="ocean currents around the world" class="wp-image-1893436"/><figcaption>Ocean currents move water around the globe in a consistent and directional flow. <a href="https://www.shutterstock.com/g/designua">Designua</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-sun-wind">Sun &amp; Wind</h3>



Similar to their impact on climate, the wind and sun control the ocean currents. Prevailing winds are air currents that stay consistent in a specific place or during a specific season. They push water around the globe in predictable patterns. But where do the winds come from? That’s where we look a bit further from the earth’s atmosphere… to the sun!



The sun’s radiation is strongest at the equator and dissipates toward the poles. Consequently (and perhaps obviously), the air at the equator heats up and moves north and south while the air at the poles cools down and moves toward the equator. Fronts of hot and cold air pockets collide to create pressure differentials. Combined with other factors, the resulting wind currents cause peaks and valleys in the ocean’s surface. Though they are subtle to an ocean traveler, the peaks are called “<a href="http://www.tsgc.utexas.edu/topex/activities/topex_basics/topex08.html" target="_blank" rel="noopener">sea surface hills</a>,” and can be detected by satellites.&nbsp;



<h4 id="h-gravity-rotation">Gravity &amp; Rotation</h4>



The earth’s forces play a significant role in directing the ocean’s currents. The peaks and valleys created by the sun and wind are immediately at the whim of gravity. Gravity pulls the water down from the hills toward the valleys. But the water never travels in a straight line. Because of the earth’s rotation, gravity pulls the water into the valleys in a curving trajectory. These currents can be further explained by the Coriolis Effect.



<figure class="wp-block-image alignnone size-large wp-image-1893437"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_1841520682-1024x811.jpg" alt="coriolis effect" class="wp-image-1893437"/><figcaption>The Coriolis Effect. <a href="https://www.shutterstock.com/g/Fouad+A.+Saad">Fouad A. Saad</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-the-coriolis-effect">The Coriolis Effect</h3>



You’ve probably heard of the <a href="https://earth.usc.edu/~stott/Catalina/Oceans.html" target="_blank" rel="noopener">Coriolis Effect</a> either in the context of climate or plane travel. The Coriolis Effect explains the influence of the Earth’s rotation on objects in a fluid environment (i.e. not on solid ground). Because the Earth is a sphere, a point on the equator (the largest circumference) will travel at a higher velocity than a point closer to one of the poles. This gets really interesting when we think of how this impacts currents.&nbsp;



<ul><li style="font-weight: 400;">North or South Movement: When water moves in a northern or southern direction, it continues moving at its starting velocity. Since the earth rotates counterclockwise (from west to east), the flow of water moving away from the equator will be pulled to the right with the direction of rotation since it started at a higher velocity. On the other hand, water moving away from the poles starts is moving slower than the rotation closer to the equator. Therefore those currents will be pulled in a clockwise direction against the rotation of the Earth.&nbsp;</li><li style="font-weight: 400;">East or West Movement: Currents that flow toward the east or west are affected by the earth’s rotation in a whole different way. If a current travels to the east with the rotation, it speeds up and is pulled toward the Equator. On the other hand, a current traveling west in the opposite direction of the earth’s rotation will slow down and be pulled toward one of the Earth’s poles.&nbsp;</li></ul>



Water depth does impact these trends. As the ocean deepens, the Coriolis Effect pulls water at slightly different angles.



<h3 id="h-currents-ecology">Currents &amp; Ecology</h3>



Just as currents move different <a href="https://www.earth.com/news/marine-heatwaves-will-intensify-in-the-strongest-ocean-currents/" target="_blank" rel="noopener">temperatures of water</a> around the world, they provide free transportation for ocean life. Turtles and whales use currents to help speed up their annual migrations across the open ocean. Additionally, many species find new homes and increase their genetic diversity by traveling with currents. And not just animals use them! Currents carry mats of seaweed, ocean algae, and even debris like logs and trash across the globe.



<h2 id="h-waves">Waves</h2>



While ocean currents take water thousands of miles around the globe, waves move water at a much smaller scale. Though waves impact a microcosm of the earth, they have a powerful influence on local ecosystems and coastlines. Ocean waves form due to the force of the wind rushing across the surface of the water. They are distinct from currents and tides because of their shape, longevity, and direction.



The wind speed, duration of gust, and the area of water that the wind blows over (aka the fetch) impact the wave height. The famous surfing waves of Hawaii, Tahiti, and California result from a long buildup over huge expanses of open water. Waves can also be tiny. They are considered mere ripples when they are less than one foot tall. To <a href="https://www.earth.com/earthpedia-articles/basic-ocean-terms/" target="_blank" rel="noopener">measure a wave</a>, scientists use the same vocabulary that sound waves are measured in, including trough and crest, amplitude, and frequency.



<h3 id="h-waves-ecology">Waves &amp; Ecology</h3>



Though small in scale compared to currents and tides, waves exert a powerful influence on coastal areas due to their repetitive nature. Everything from shallow water waves to tidal waves shapes coastlines by adding and taking away substrate. Through this give and take, waves create shoreline habitats.



<h2 id="h-tides">Tides</h2>



Tides are distinct changes in sea level across great expanses due to the gravitational pull of the sun and moon. Essentially, large waves that rush from one side of the ocean to the other, tides create a huge impact on the earth’s shorelines.



<h3 id="h-stages-of-tides">Stages of Tides</h3>



A flood tide describes the time when the rising water covers the intertidal zone to reach its maximum water height at high tide. Subsequently, the water lowers to reveal the intertidal zone, called the ebb tide. Finally, the low tide means the water reaches its lowest level and begins the process again.&nbsp;



<h3 id="h-what-causes-the-tides">What Causes the Tides?</h3>



Tides are caused by the <a href="https://www.whoi.edu/cms/files/lecture01_21351.pdf" target="_blank" rel="noopener">gravitational forces</a> of the moon and sun on the earth’s oceans. Due to the moon’s orbit, it changes location throughout the day. Depending on which side of the earth it’s on, it pulls the world’s oceans in that direction.



Though tidal patterns are primarily impacted by the moon’s position, gravity from the sun can also play a role. When the sun and moon line up with the earth at a new moon and full moon, they create a celestial event called a syzygy. In these moments, the sun amplifies the gravitation pull of the moon. Consequently, the <a href="https://www.earth.com/news/supermoon-causes-high-tides-in-the-uk/" target="_blank" rel="noopener">tides intensify</a> with highs and lows reaching monthly extremes. These events are known as spring tides.&nbsp;



On the other hand, a half-moon forms a 90° angle with the earth and sun, completely losing any amplification from the sun. Half-moons produce neap tides which are the monthly minimums of the tidal range.



<h3 id="h-types-of-tides">Types of Tides</h3>



Tides typically appear in one of three categories based on their frequency and tide height: diurnal tides, semidiurnal tides, and mixed tides. Diurnal tides cycle once per day with a single high tide and single low tide. Semidiurnal tides have two high tides and two low tides with their tide heights being approximately equal. Lastly, mixed tides usually have two highs and two lows, but one high tide and one low tide will be more extreme than the others.



<h3 id="h-tides-ecology">Tides &amp; Ecology</h3>



Operating on a slower timescale than waves, though with similar predictability, tides impose an enormous influence on the world’s ecology. Tidal pools provide sanctuary for delicate marine invertebrates and a reliable food source for the shorebirds and marine mammals that peruse tidal zones. Some creatures, like sea turtles, rely on the outgoing tides to help with juvenile dispersal.



<figure class="wp-block-image alignnone size-full wp-image-1893439"><img src="https://www.earth.com/wp-content/uploads/2021/07/shutterstock_179293964.jpg" alt="tide pools" class="wp-image-1893439"/><figcaption>Tide pools provide sanctuaries for marine life. <a href="https://www.shutterstock.com/g/Ethan+Daniels">Ethan Daniels</a>/Shutterstock.com</figcaption></figure>



&nbsp; &nbsp; Marine and coastal wildlife aren’t the only creatures that rely on the tides for habitat and food. Humans have learned to harness <a href="https://www.earth.com/news/sea-energy-power-future/" target="_blank" rel="noopener">tidal power</a> for our own benefit. Similar to harnessing the wind, using turbines to capture tidal energy provides a sustainable energy source for coastal communities worldwide.



<h2 id="h-waves-tides-and-currents-continuous-movement">Waves, Tides, and Currents: Continuous Movement</h2>



The complexities of the oceans don’t stop here. The saying that we know more about the surface of the moon than we do about the oceans continues to prove itself true as marine biologists continue to make new discoveries. While we still have plenty to learn about the ocean in general, having a greater appreciation for the distinct ways that the oceans move is a good start.



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Wave, Tides, Currents: An Important Distinction

Earth’s waters are constantly moving. They change form in the...

We live on a beautiful, shifting, and evolving planet. Earth is the one place we know of in our vast and expanding galaxy that sustains life.&nbsp; <a href="https://www.usgs.gov/special-topic/water-science-school/science/how-much-water-there-earth?qt-science_center_objects=0#qt-science_center_objects">About 71% of the earth</a> is water-covered today, and with global warming increasing in velocity, sea-level rise will continue to shape our societies, cities, and species.&nbsp;



Today we're going to take a beginner's look at sea-level rise. Continue reading to learn more about what it is, why it happens, the ripple effects of rising sea levels, and action items you can undertake today.&nbsp;



<h2 id="h-climate-change-today">Climate Change Today&nbsp;</h2>



Our planet is changing - fast. Scientists and other scholars have named this epoch the "<a href="https://www.earth.com/news/humans-are-responsible-for-rising-sea-levels/">Anthropocene</a>" because of the way our behavior, governments, and population have impacted the globe.



But climate change is not new for the earth. In fact, our home planet has been defined by it. An ice age is an example of climate change. An asteroid can impale the Earth's atmosphere and cause a climate change and global extinction event - as <a href="https://web.archive.org/web/20190507051856/https://pdfs.semanticscholar.org/8d43/36c3d3e40d27390e37941e4affe0cff84bb2.pdf">in the case of dinosaurs 66 million years ago.&nbsp;</a>



What's different about climate change in recent decades is the way in which human activity has caused such swift and irreparable damage. There is no single culprit we can point to, but a variety of factors compounding into horrific shifts in bio-health and sustainability. Our destruction of biodiverse habitats and insatiable appetite for fossil fuels are just two examples. These extractive and exploitive practices don't only come at the expense of forests and rivers. "Progress" and "efficiency" have come at terrifying costs to human rights and dignity as well.&nbsp;&nbsp;



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2021/06/beach-4914403_1280-1024x682.jpg" alt="trash on a beach " class="wp-image-1892535"/><figcaption><a href="https://pixabay.com/users/sergeitokmakov-3426571/">sergeitokmakov</a> / Pixabay</figcaption></figure>



<h2 id="h-beginning-to-understand">Beginning To Understand</h2>



<h2 id="h-">&nbsp;</h2>



There are many angles to look at in the midst of this crisis - and it can be hard to know where to being. An important aspect of climate change and climate crisis is sea-level rise. Looking at this phenomenon can be a good starting point and a way to understand how closely linked our world truly is.&nbsp;



Scientists warn of global sea-level rise in <a href="https://climate.nasa.gov/vital-signs/sea-level/">millimeters per year</a>. This may not sound like much, but it does add up to <a href="https://www.earth.com/news/east-coast-sea-levels-rising-at-the-fastest-rate-in-2000-years/">truly massive impacts on our globe</a> - especially considering that over 40% of the world's population lives in coastal areas. Even if you live far away from coastal cities, this means unprecedented shifts in weather patterns, water levels, and arable land use.&nbsp;



<h2 id="h-what-is-sea-level-rise">What Is Sea-Level Rise?&nbsp;</h2>



Let's start with the basics, here. Sea level rise is pretty much exactly how it sounds. The sea surface is rising up around the world. According to NOAA, the "<a href="https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level">global mean sea level has risen 8-9 inches since 1880</a>". Scientists are able to track this trajectory through history via geological records and by testing samples of ice. They are also able to track changes in ocean level by using <a href="https://oceanservice.noaa.gov/facts/tide-gauge.html">tide gauges</a>.&nbsp;



They warn that one-third of the ocean water rise has come in during the last two and a half decades. The rate of sea-level rise is increasing. Specific locations will see more or less than the global average due to a variety of factors. Instances of erosion, flood control, and ground settling will determine the sea level rise in local areas across the Atlantic, Pacific, Indian and Arctic oceans.&nbsp;



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2021/06/maldives-1993704_1280-1024x575.jpg" alt="maldives " class="wp-image-1892536"/><figcaption><a href="https://www.shutterstock.com/g/Anncanpan">Anncanpan</a>/Shutterstock.com</figcaption></figure>



<h2 id="h-what-causes-sea-level-rise">What Causes Sea-Level Rise?&nbsp;</h2>



According to NASA's global <a href="https://climate.nasa.gov/vital-signs/sea-level/">climate change information</a>, global sea-level rise is caused by two combined factors. Firstly, there is added water to our oceans from melting ice sheets, sea ice, and glaciers. We call this meltwater. Secondly, saltwater expands as it warms up. This phenomenon is called <a href="https://www.climate.gov/news-features/understanding-climate/climate-change-global-sea-level">"thermal expansion"</a>. According to NASA data, the global average of water levels has risen <a href="https://climate.nasa.gov/vital-signs/sea-level/">almost 4 inches</a> since 1995.



Greenhouse gases, for all the bad rap they get these days, are a natural phenomenon that insulates our planet from the cold of outer space. So while this is an occurrence that has protected the earth's atmosphere and <a href="http://css.umich.edu/factsheets/greenhouse-gases-factsheet">living biome for millennia</a>, it is the anthropogenic emissions (humans plus fossil fuels) that have thrown this delicate balance way off.&nbsp;



As our global temperature heats up and global warming intensifies, the ice melt combines with thermal expansion. It is a cycle the spells disaster for many species including our own.&nbsp;



<h2 id="h-the-ripple-effects-of-sea-level-rise">The Ripple Effects of Sea-Level Rise&nbsp;</h2>



Higher sea levels globally obviously impact local sea levels. When we talk about inches, we are also talking about people's lives. From Miami, Florida to the burrows of New York, a couple of inches can mean a crisis for millions of people. The <a href="https://www.brookings.edu/research/the-climate-crisis-migration-and-refugees/#:~:text=In%202018%2C%20the%20World%20Bank,any%20point%20in%20human%20history.">World Bank estimates</a> that there will be over 140 million climate refugees by 2050.



As the planet warms and sea levels rise, we lose more and more sea ice each year as well. Sea ice is different than ice sheets in that it is simply <a href="https://nsidc.org/cryosphere/seaice/index.html">frozen ocean water</a>. In comparison, ice sheets (like the Greenland ice sheet) and glaciers are actually <a href="https://nsidc.org/cryosphere/seaice/index.html">made up of freshwater</a>.&nbsp;



Sea ice covers about <a href="https://oceanservice.noaa.gov/education/tutorial_currents/05conveyor3.html">25 million square kilometers in the arctic</a> and Antarctica. That's double the size of Canada, to put it in perspective. These formations are of critical importance to wildlife and indigenous people of the arctic. And even if most of us never see it, living far from an arctic region, sea ice has big climate impacts that affect all of us.&nbsp;



This is because sea ice has a bright surface. Further, a lot of the light that hits its surface is reflected back into space. This process allows polar regions to stay cool. But with sea ice melting with warming temperatures, there is less and less bright surface area to reflect light. This means that the oceans of the polar regions will be even warmer - leading to more melting ice. It is a vicious cycle.&nbsp;



<figure class="wp-block-image"><img src="https://www.earth.com/wp-content/uploads/2021/06/iceberg-404966_1280-1024x701.jpg" alt="iceberg" class="wp-image-1892537"/><figcaption><a href="https://www.shutterstock.com/g/Andrey-28">Andrey-28</a>/Shutterstock.com</figcaption></figure>



<h3 id="h-ocean-currents">Ocean Currents</h3>



Another ripple effect of global warming and rising sea levels is that of the ocean currents. The currents operate like a <a href="http://www.earth.com/news/relationship-between-ocean-currents-and-climate-change/">global conveyor belt</a>. They transport warmer water from the equator up to the poles and cooler water from the poles back down to equatorial regions. Scientists warn this is a process that is easy to disturb - especially with the influx of freshwater from ice sheets and glaciers. This cycle could very well lead to a disruption of the currents. These critical conveyor belts might slow down and even stop.&nbsp;



This would cause <a href="https://oceanservice.noaa.gov/education/tutorial_currents/05conveyor3.html">immense temperature changes</a> in previously temperate parts of the globe. There are theories to suggest that these disturbed currents will mean big changes for the deep sea - much of which we have yet to explore. In essence, we are messing with parts of our globe that remain unexplored and unexplained - making the impact that much more volatile.&nbsp;



<h3 id="h-reactionary-plans-to-these-ripple-effects">Reactionary Plans To These Ripple Effects&nbsp;</h3>



Some municipalities along the east coast of the US and other coastal areas around the globe are working to implement projects such as Seawalls. Seawalls are <a href="https://www.e-education.psu.edu/earth107/node/1062">onshore structures that prevent flooding from storm surges</a> and waves. The idea is to protect the land and structures behind the sea walls from rising sea levels.&nbsp;



While these sorts of initiatives will be important for temporary assistance to sea-side communities and alleviating flood risk for at-risk neighborhoods, it is a reactionary measure. We must be dedicated to proactively shifting our culture, legislation, and economic models towards sustainable systems and ways of life.



There is a lot of additional information to gather on various platforms on the internet and at your local library. The <a href="https://www.noaa.gov/">National Oceanic and atmospheric administration</a> is a great place to start - as is your local newspaper or neighborhood forums on conservation and restoration efforts.&nbsp;



<h2 id="h-action-items">Action Items&nbsp;</h2>



The trajectory of recent years has been anything but hopeful. But gaining a deeper understanding of the phenomenon occurring around us can be <a href="http://www.earth.com/video/the-evolution-of-sea-level-rise-on-the-west-coast/">an empowering way to take action</a>.&nbsp;



For instance, let's look at methane and carbon dioxide. Both of these primary greenhouse gases are naturally occurring - and are not inherently "bad" or "good". Here's the problem: their concentration within the atmosphere is wreaking havoc. As greenhouse gases heat our atmosphere and our oceans, the sea level continues to rise.&nbsp;



Some ideas and ways to divorce yourself from this imbalance? Adopt a mostly vegetarian diet and ride your bike. Investigate how groundwater is used in your area. Even if you live far away from ocean water, you can investigate the aquatic habitats (such as marshes and other wetlands) in your area that need protection and restoration.&nbsp;



But as the desperation of this situation naturally suggests, individual actions will not be sufficient to divert our species' path from annihilation. We must empower entire communities, nation-states, and global initiatives to make swift and bold actions on a collective level.



<h2 id="h-in-conclusion-an-uncertain-future">In Conclusion: An Uncertain Future&nbsp;</h2>



Much of the predicted future sea-level rise may be out of our control in the decades to come, but there are indications that our choices and policies today have the capacity to mitigate the crisis at hand. And while sea-level change is inevitable, that doesn't mean we can't tackle the systems and infrastructure that cause harm. Human beings are an adaptable species. It is possible to restore ecosystems, instead of destroying them.&nbsp;&nbsp;



No matter where you live or where you are, you've learned the basics of sea-level rise and can use that knowledge to activate change in your own community. All over the world, groups are organizing on behalf of this beautiful planet. Use your skills! 



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

A Simple Guide to Understanding Sea-Level Rise

We live on a beautiful, shifting, and evolving planet. Earth...

You've been rocking on the boat all day and haven't had even the faintest nibble. Suddenly, the line jerks and you run over to it to begin an hours-long battle with the mystery fish. Imagine the thrill of finally pulling a 1000 pound marlin out of the depths of the open ocean during your deep-sea fishing charter. It's a thrill that some fisherpeople get addicted to, a feeling they live for.
Our deep oceans contain the biggest fish in the world. Fishers will travel the world over for the chance to reel in a honkin' tuna or a shiny Dorado. Deep-sea fishing is a considerable recreation and travel industry that supports fishing guide businesses around the world.


[caption id="attachment_1892427" align="alignnone" width="1920"]<img class="wp-image-1892427 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/sea-3652697_1920.jpg" alt="open ocean" width="1920" height="1280" /> Ain't much to look at when you're deep-sea fishing. Photo by <a href="https://pixabay.com/users/dimhou-5987327/" target="_blank" rel="noopener">Dim Hou</a> via <a href="https://pixabay.com/photos/sea-water-ocean-quiet-horizon-3652697/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>What is Deep-Sea Fishing?</h2>
Most people call any type of recreational fishing done below 100 feet in ocean waters deep-sea fishing.  While commercial fishing boats often fish at these depths, this article won't cover that kind of deep-sea fishing.
Any sort of freshwater or saltwater bay fishing isn't considered deep water fishing. Since the deep seas are, by their nature, far from land, deep-sea fishing is always done on a boat. Sometimes boats can get to deep-sea depths relatively close to shore. Other times this sort of fishing is done dozens, or even hundreds, of miles from the nearest land.
Some fisherpeople also call this type of fishing sport fishing or trophy fishing.


[caption id="attachment_1892430" align="alignnone" width="1280"]<img class="wp-image-1892430 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/hanging-3045269_1280.jpg" alt="deep-sea fishing lures" width="1280" height="835" /> Various kinds of deep-sea fishing lures. Photo by <a href="https://pixabay.com/users/paulbr75-2938186/" target="_blank" rel="noopener">Paul Brennan</a> via <a href="https://pixabay.com/photos/hanging-hook-lures-fishing-3045269/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>Different Types of Deep-Sea Fishing</h2>
Most fishers hire a guiding company for their deep-sea fishing excursions. These fishing charters vary depending on the location, guide company, and species of fish. One thing is certain; deep-sea fishing isn't for those without their sea legs. The open ocean has big, rolling waves, which constantly rock even the nicest boats. With only water on the horizon, even strong-stomached anglers can get nauseous. You can opt for either a deep-sea fishing charter with a group or as a private charter.
Guides will usually let their customers try various kinds of fishing methods during a deep-sea fishing excursion. These methods can include trolling, chumming, popping, and jigging. Trolling is where anglers dangle their lines behind a quickly moving boat, sometimes with live bait. Chumming includes throwing bait onto the water to lure deep-sea fishes up to the surface. Jigging is a type of lure fishing where the lure is attached to a lead weight that makes it dance in a particular way deep beneath the surface. Fishers usually set these jigs at various depths with the boat slowly drifting along. Popping is a more unusual way to deep-sea fish. It involves using larger lures called 'poppers' that slap the water to make sounds that entice nearby fish.

<h3>Half-Day Trips</h3>
The cheapest option for sport fishing trips is usually a half-day tour. These shorter tours typically don't go too far from the land because it takes a long time to venture way out into the ocean.

<h3>Full-Day Trips</h3>
Full-day fishing trips are a common type of trophy fishing. These charter boats leave the shore early in the morning and sometimes return after sunset. Full-day trips give anglers a better chance of trying different methods of deep-sea fishing.

<h3>Night Fishing Adventures</h3>
Some kinds of fish only bite at night. To catch these fish some guides lead night-time deep-sea fishing tours.

<h3>Multi-Day Excursions</h3>
These deep-sea fishing trips are the creme de la creme. While they are the most expensive, they also offer the widest variety of opportunities. Fishers can expect to fish during different times of day with multiple methods. This variety gives anglers the best chance to catch their dream fishes.


[caption id="attachment_1892431" align="alignnone" width="1280"]<img class="wp-image-1892431 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/boat-5429345_1280.jpg" alt="deep-sea fishing" width="1280" height="857" /> Dorado, or mahi-mahi, is an exciting deep-sea fish species to catch. Photo by <a href="https://pixabay.com/users/larsen9236-47917/" target="_blank" rel="noopener">Lisa Larsen</a> via <a href="https://pixabay.com/photos/boat-fishing-fishing-boat-5429345/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>What Kinds of Fish do Sport Fisherpeople Catch?</h2>
Most of the desired deep-sea fish live in the pelagic zone of the ocean. The pelagic zone is all of the ocean that isn't close to some sort of boundary. These boundaries include the seafloor, the ocean surface, and any coast. Deep-sea fishers usually aren't going for <a href="https://www.earth.com/earthpedia-articles/seven-surprising-secrets-of-the-deepest-sea-creatures/" target="_blank" rel="noopener">those awfully strange</a>, truly deep-ocean fish that live near the seafloor. The pelagic ecosystem is based on photosynthetic plankton. These plankton live near the upper reaches of the pelagic zone because they need sunlight to live. Pelagic fishes will <a href="https://www.vox.com/unexplainable/22348461/ocean-twilight-zone-mysteries-unexplainable-podcast" target="_blank" rel="noopener noreferrer">migrate to different depths</a> or locations based on the availability of plankton.
All coasts of the U.S. have deep-sea fishing opportunities. The East coast <a href="https://www.frontiersin.org/files/Articles/491041/fmars-07-00012-HTML/image_m/fmars-07-00012-g005.jpg" target="_blank" rel="noopener noreferrer">represents about 40%</a> of recreational marine fishing. The Gulf of Mexico and Hawaii account for <a href="https://www.frontiersin.org/files/Articles/491041/fmars-07-00012-HTML/image_m/fmars-07-00012-g005.jpg" target="_blank" rel="noopener noreferrer">20% each</a>. Alaska and the West coast account for <a href="https://www.frontiersin.org/files/Articles/491041/fmars-07-00012-HTML/image_m/fmars-07-00012-g005.jpg" target="_blank" rel="noopener noreferrer">about 10% each</a>. Abroad, coastal countries around the world offer unique deep-sea charters and experiences.

<h3>West Coast</h3>
Off the California, Oregon, and Washington coast, people like to fish for yellowtail, sturgeon, albacore tuna, rockfish, barracuda, white sea bass, and lingcod. The ocean around California's Channel Islands is a uniquely beautiful place to fish with abundant deep-sea fisheries.

<h3>East Coast</h3>
Off the East coast of the U.S. people catch bluefin and yellowfin tuna, cod, striped bass, and <a href="https://www.earth.com/news/volcanic-eruption-fishing-industry/" target="_blank" rel="noopener">mackerel</a>. People can even leave for these trips from mega-cities like New York and Boston.

<h3>Gulf of Mexico</h3>
The Gulf of Mexico is a major deep-sea fishing destination. People can access the Gulf of Mexico from Florida, Texas, the eastern coast of Mexico, and the Caribbean islands. This gulf is a particularly biodiverse body of water, making it an interesting place to sport fish. Fishers can catch Dorado, shark, king mackerel, red snapper, and Spanish mackerel.

<h3>Alaska</h3>
Alaska is world-renowned for its fishing. This massive state has plenty of open ocean to choose from. Deep-sea fishers can expect to fish for massive halibut and salmon, as well as crab.

<h3>Hawaii</h3>
Who wouldn't want to fish the tropical waters of Hawaii? As the only islands for hundreds of miles around, Hawaii is an excellent jumping-off point to quickly access the true open ocean. Fishers can fish for awesome species in Hawaii like the Yellowfin ahi tuna, giant blue marlin, dorado, sailfish, swordfish, and wahoo.


[caption id="attachment_1892429" align="alignnone" width="1920"]<img class="wp-image-1892429 size-full" src="https://www.earth.com/wp-content/uploads/2021/06/charter-4682523_1920.jpg" alt="deep-sea fishing rods" width="1920" height="1281" /> Fishing rods wait for bites from deep-sea fish. Photo by <a href="https://pixabay.com/users/jasongillman-1088827/" target="_blank" rel="noopener">Jason Gillman</a> via <a href="https://pixabay.com/photos/charter-fishing-water-marine-4682523/" target="_blank" rel="noopener">Pixabay</a>.[/caption]
<h2>Does Deep-Sea Fishing Harm Fish Populations?</h2>
In raw numbers, deep-sea fishing doesn't account for a whole lot of the global fish take. <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00012/full" target="_blank" rel="noopener noreferrer">Less than 1%</a> (by mass) of marine fish killed annually are by recreational fishers. Industrial fishing fleets take the vast bulk of the world's catch, with subsistence artisanal fishers taking varying degrees depending on the fishery. <a href="http://www.seaaroundus.org/data/#/eez/44?chart=catch-chart&amp;dimension=sector&amp;measure=tonnage&amp;limit=10" target="_blank" rel="noopener noreferrer">The Bahamas</a> is an extreme case where 30% of fish taken out of the ocean is for recreation.
However, even though recreational fishing doesn't take a huge amount of fish out of the ocean, some scientists are concerned with the species of fish and the particular individuals that recreational fishers target.

<h3>Small Numbers Can Be Deceiving</h3>
Even though deep-sea fishers don't catch that many fish, the particular species and individuals they target can affect fish populations. Trophy fishers often aim to catch the big fish species that reproduce slowly. <a href="https://www.biologicaldiversity.org/species/fish/Atlantic_bluefin_tuna/natural_history.html#:~:text=LIFE%20CYCLE%3A%20Atlantic%20bluefin%20tuna,octopus%2C%20crabs%2C%20and%20sponges." target="_blank" rel="noopener noreferrer">Tuna</a> often live 40 years. Most other deep-sea fishes sought by recreational fishers live decades. Fish that live a long time typically take more years to reach their reproductive age. This means that if the adults from a population of these fish are reduced by overfishing, it can take a long time for their population to rebound.
Moreover, sport fishers target the largest individuals of these slowly reproducing species. By their nature, these large fishes are <a href="https://www.sciencedirect.com/science/article/abs/pii/S0308597X14001754?via%3Dihub" target="_blank" rel="noopener noreferrer">often the best reproducers</a> in the population. Some scientists are concerned that targeting the healthiest individuals of a population puts significant pressure on the population. Sports fishers are increasingly turning to catch-and-release methods instead of killing fish. While this method is preferable from the fish's standpoint, it can <a href="https://www.earth.com/news/catch-release-fishing-damages/" target="_blank" rel="noopener">still have lasting impacts</a> on the fish.
In particular, the trophy fishing of <a href="http://www.seaaroundus.org/sea-around-us-collaborator-says-shark-fishing-should-be-considered-ocean-vandalism/#more-18610" target="_blank" rel="noopener noreferrer">threatened species of sharks</a> is alarming.
Lastly, outside of the U.S., <a href="https://www.frontiersin.org/articles/10.3389/fmars.2020.00012/full" target="_blank" rel="noopener noreferrer">scientists don't have much data</a> on what species of fish and how many fish recreational fishers take out of the oceans. Their estimates vary from 0.5 million tons per year to 10 million tons per year! Without this data, it is difficult to say the extent to which recreational fishing impacts fish populations.

<h2>Get Fishing!</h2>
With a fish species, a destination, and a budget in mind, you can figure out the fishing trip that is right for you. Maybe it's near your home, or perhaps it is a getaway to some tropical coastline half the world away. Best of luck on your angling adventures!
Featured image by <a href="https://pixabay.com/users/scottslm-10594535/" target="_blank" rel="noopener">Scott</a> via <a href="https://pixabay.com/photos/deep-sea-fishing-boat-fishermen-boat-5847660/" target="_blank" rel="noopener">Pixabay</a>.
Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

What Actually is Deep-Sea Fishing?

You've been rocking on the boat all day and haven't...

A nudibranch is a kind of sea slug. With over <a href="https://ocean.si.edu/ocean-life/invertebrates/collage-nudibranch-colors" target="_blank" rel="noopener">3,000 species</a> in the order of Nudibranchia, these colorful clowns are full of intrigue and surprise. Living in a variety of marine ecosystems, nudibranchs have some fascinating qualities...and they aren’t trying to be discrete. These shell-less gastropods have evolved into a rainbow of bright colors and patterns, with some crazy appendages too! In fact, the name “nudibranch” derives from the Latin word nudus meaning “naked” and the Ancient Greek word bránkhia meaning “gills,” referring to their naked gills that protrude like stalks or feathers from their bodies. Beyond their wild appearances, nudibranchs have also developed some pretty alien adaptations. Read on to learn more about their incredible ecology and aquatic superpowers!
 
<h2>Life As a Nudibranch</h2>
 
These bejeweled slugs are not just funny-looking, they also have a fascinating ecology. Below, we’ve provided a bit of background on nudibranchs, including helpful terms and fun facts.
 
[caption id="attachment_1892200" align="alignnone" width="1920"]<img class="size-full wp-image-1892200" src="https://www.earth.com/wp-content/uploads/2021/05/nudibranch-202327_1920.jpg" alt="Nudibranch" width="1920" height="1082" /> Image by <a href="https://pixabay.com/users/vjacob1-78318/?utm_source=link-attribution&amp;utm_medium=referral&amp;utm_campaign=image&amp;utm_content=202327" target="_blank" rel="noopener">Vivi Ann Jacobsen</a> from Pixabay.[/caption]
 
<h3>Nudibranch Morphology</h3>
 
The first impression of a nudibranch might make you think it’s the love child of the 1970’s psychedelic era and aliens from the future. But we (along with marine biologists around the world) have learned to accept a wild appearance when it comes to ocean life. Nevertheless, these squishy invertebrates should get awards in both funk and spunk, given their diversity in color and texture.
However, there are a handful of characteristics that all members of the order have. For starters, nudibranchs stay smaller than 10 cm in length, though some can be microscopic while the largest species is almost 40 cm. Though different species may appear very different, their similar morphology can give us fascinating insight into their physiology. Below are a few terms and their descriptions to help you better understand these. 
 
<table>
<tbody>
<tr>
<td>Nudibranch Characteristic</td>
<td>Description &amp; Function</td>
</tr>
<tr>
<td>Mantle</td>
<td>The dorsal portion of a gastropod body. Without a shell, a nudibranch’s mantle has evolved to be quite decorative and includes the protruding cerata.</td>
</tr>
<tr>
<td>Cerata</td>
<td>External appendages of the nudibranch’s digestive and circulatory tract. Functioning as the gills, the cerata allow for gas exchange. In many species, the nematocysts are stored in the cerata and are used as the organism’s defense.</td>
</tr>
<tr>
<td>Rhinophores</td>
<td>Similar to antennae, rhinophores are sensory organs positioned on the head. Primarily used for chemosensory like smell and taste, they help the nudibranch find food.</td>
</tr>
<tr>
<td>Oral Tentacles</td>
<td>Used more for the tactile sense, the oral tentacles help the nudibranchs navigate around the seafloor.</td>
</tr>
<tr>
<td>Radula</td>
<td>At first, the radula appears to be similar to a tongue. However, on closer inspection, it is a ribbon of tiny teeth that it uses to eat its prey.</td>
</tr>
</tbody>
</table>
 
<h3>Taxonomy</h3>
 
Nudibranchs are found in the phylum Mollusca (mollusks) and share the class Gastropoda with other slugs and snails. Gastropods are the most specious class of animals outside of insects. That means we’re dealing with quite a few types of slugs and snails. They can be found on land and in water, and even these marine gastropods can be found across several different orders. That’s where our nudibranchs break off. They fall in the order of Opisthobranchia, including all the <a href="https://www.earth.com/news/sea-slug-movement-efficient-robots/" target="_blank" rel="noopener">marine slugs</a> such as sap-sucking slugs, sea hares, side gill slugs, and bubble snails. Finally, because of their diet and gill placement, the suborder Nudibranchia breaks off from the other opisthobranchs.
This classification goes further with two subgroups of nudibranchs, divided again based on more specific gill placement. Dorid nudibranchs are the most common types of nudibranchs and have a concentration of cerata that form a ring around their anus, called a branchial plume. (You read that right - they breathe where they poop!) Aeolid (or eolid) nudibranchs, on the other hand, have cerata spread more evenly across their mantle.
 
[caption id="attachment_1892199" align="alignnone" width="1920"]<img class="size-full wp-image-1892199" src="https://www.earth.com/wp-content/uploads/2021/05/nudibranch-1196451_1920.jpg" alt="Nudibranch" width="1920" height="1374" /> Image by <a href="https://pixabay.com/users/monicavolpin-1476511/?utm_source=link-attribution&amp;utm_medium=referral&amp;utm_campaign=image&amp;utm_content=1196451" target="_blank" rel="noopener">Monica Volpin</a> from Pixabay.[/caption]
 
<h3>Nudibranch Diet</h3>
 
Surprising as it may be, these small, squishy, colorful slugs are all predatory carnivores. However, hunting isn’t a very athletic pursuit. They feed on <a href="https://nsuworks.nova.edu/cnso_stucap/23/" target="_blank" rel="noopener">filter-feeding animals</a> like corals, sponges, barnacles,  and anemones. Some species of aeolid nudibranchs do trap sea jellies as their food source, though this is about as tactical as they get.  Some nudibranchs will even eat members of their own species.
 
<h3>Habitat &amp; Distribution</h3>
 
Living throughout the world’s oceans, these marine slugs peruse the seafloor from tidepools to depths up to 6,500 feet. Most species of nudibranch prefer benthic, or ground-dwelling, life and spend their time oozing across the sea bed. However, a couple of types are more agile swimmers and hunt for food near the surface or in the water column. 
 
<h3>Nudibranch Life Cycle</h3>
 
Like most gastropods, nudibranchs are hermaphrodites, meaning a single individual has both male and female genitalia. However, they can not self-fertilize, so will still seek out another nudibranch to mate. They will then lay a gelatinous mass of up to <a href="http://legacy.earlham.edu/~brickte/" target="_blank" rel="noopener">one million eggs</a>. When the baby nudibranchs hatch, the larvae look more like snails as they have tiny shells. When the larval form metamorphosizes, however, the shells fall off to reveal the shell-less adults in all their colorful glory. Like many mollusks, nudibranchs don’t live very long. With some fluctuation depending on environmental conditions and resource availability, the lifespan for most species sits around 18 months.
 
[caption id="attachment_1892198" align="alignnone" width="1920"]<img class="size-full wp-image-1892198" src="https://www.earth.com/wp-content/uploads/2021/05/nudibranch-2328630_1920.jpg" alt="Nudibranch" width="1920" height="1080" /> Image by <a href="https://pixabay.com/users/misterflo-5415806/?utm_source=link-attribution&amp;utm_medium=referral&amp;utm_campaign=image&amp;utm_content=2328630" target="_blank" rel="noopener">Florent Horn</a> from Pixabay.[/caption]
 
<h2>Nudibranch Superpowers</h2>
 
Just as a pretty addition to the coral reef, nudibranchs are fascinating. But there’s a bit more to their crazy and beautiful world. In fact, most nudibranchs have some unbelievable adaptations, akin to superpowers. Who knows? Maybe the next blockbuster superhero movie will be inspired by these marine slugs!
 
<h3>Stealing the Sting</h3>
 
If you ask a nudibranch its favorite meal, it will most likely say anything in the phylum Cnidaria. This fascinating and diverse group of creatures includes <a href="https://www.earth.com/news/uncovering-the-secrets-of-coral-evolution/" target="_blank" rel="noopener">coral</a>, true jellyfish, hydroids, anemones, and box jellies. And they all have one thing in common...they sting. 
All <a href="https://www.earth.com/news/jellyfish-kill-toxin-genes/" target="_blank" rel="noopener">cnidarians</a> have specialized stinging cells called <a href="https://ucmp.berkeley.edu/cnidaria/cnidaria.html" target="_blank" rel="noopener">nematocysts</a>. Each cell contains a barbed, coiled thread that can spring out in self-defense and inject the threat with venom! This strategy has mostly worked out for cnidarians, as very few animals want to eat them. But that leads us back to the real stars of the show. 
Nudibranchs demonstrate a phenomenon in which they can eat their cnidarian prey without activating the nematocysts. Instead, they are able to <a href="http://legacy.earlham.edu/~brickte/" target="_blank" rel="noopener">incorporate these specialized cells</a> into their own anatomy by passing the nematocysts from their digestive tract to their skin and repurpose them for their own self-defense. Nudibranchs essentially absorb the defense adaptations of another creature for their own gain! 
 
<h3>The Blue Dragon</h3>
 
One amazing example of this can be found in the <a href="http://www.eeb.cornell.edu/harvellcom/2019/03/25/voyage-of-the-blue-dragon/" target="_blank" rel="noopener">Blue Dragon</a> nudibranch with the scientific name Glaucus atlanticus. Unlike its bottom-dwelling relatives, this nudibranch swims toward the surface to pick off its prey. Quite the daring feat, as its prey is none other than the Portuguese man o’ war. To hunt it, the nudibranch sucks air into its body to help it rise to the surface where it floats upside down, waiting for its prey. Since the Blue Dragon steals from one of the most dangerous siphonophores in the ocean, its readapted sting can also pack quite the punch. 
 
[caption id="attachment_1892197" align="alignnone" width="1920"]<img class="wp-image-1892197 size-full" src="https://www.earth.com/wp-content/uploads/2021/05/chromodoris-1537996_1920.jpg" alt="Nudibranch" width="1920" height="1440" /> Image by <a href="https://pixabay.com/users/arhnue-1896944/?utm_source=link-attribution&amp;utm_medium=referral&amp;utm_campaign=image&amp;utm_content=1537996" target="_blank" rel="noopener">Arhnue Tan</a> from Pixabay.[/caption]
 
<h3>Photosynthetic Animals?!</h3>
 
Not only can nudibranchs steal the stinging cells from their prey, but a small group of aeolid nudibranchs can also swipe another amazing superpower. These marine slugs add a type of zooxanthellae (microscopic green algae) to their diets, allowing them to incorporate cells containing chloroplasts into their own anatomy. As a result, they can make their own food from sunlight through <a href="https://www.earth.com/earthpedia-articles/things-you-forgot-in-high-school-photosynthesis-in-plants/" target="_blank" rel="noopener">photosynthesis</a>! 
 
<h3>Coloration</h3>
 
Famous for their bright colors, nudibranch’s appearance captivates scuba divers and blog readers alike. But why do these sea slugs look like they are headed to Coachella? Depending on the species, there can be two different answers to this question: camouflage or aposematism.
When an organism uses striking colors and patterns to warn of its toxicity, this adaptation is called aposematism. Think of it as a visual “Don’t Eat Me” sign. Since nudibranchs are able to absorb the stinging cells of their prey, this warning is a good thing for their potential predators.
In addition, many nudibranchs spend most of their time perched on the corals, sponges, and anemones that they eat. Since many of these ocean critters are brightly colored themselves, the nudibranchs are barely perceptible among the reefs. It turns out that their spectacular colors make for a cryptic camouflage (blending in with their environment)!
 
<h2>A World to Explore</h2>
 
Without a doubt, these tiny, rainbow slugs are a true treat of marine life. And as official members of the nudibranch fan club, we can all do our part to support more research, education, and conservation of these incredible animals. Unfortunately, most species haven’t been accessed, so we don’t have a great idea how environmental challenges affect them. However, early research shows that obstacles such as pollution, habitat degradation, and <a href="https://www.earth.com/news/ocean-acidification-will-be-worse-than-expected-in-the-arctic/" target="_blank" rel="noopener">ocean acidification</a> have caused declines in nudibranch populations. For the sake of all the amazing oceanic ecosystems, let’s do what we can to keep the psychedelic nudibranch around to inspire generations to come.
[Featured Image by <a href="https://unsplash.com/@kmkr" target="_blank" rel="noopener">Kris Mikael Krister</a> on Unsplash.]


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Diving Into the Crazy and Beautiful World of Nudibranchs

A nudibranch is a kind of sea slug. With over...

Cnidarians

Cnidaria is a phylum of the animal kingdom. It is...

The overwhelming majority of our Earth’s surface - 71% - is water. Of that water, <a href="https://www.usbr.gov/mp/arwec/water-facts-ww-water-sup.html#:~:text=Water%20covers%20about%2071%25%20of%20the%20earth's%20surface.&amp;text=97%25%20of%20the%20earth's%20water,most%20industrial%20uses%20except%20cooling).&amp;text=3%25%20of%20the%20earth's%20water%20is%20fresh." target="_blank" rel="noopener noreferrer">97%</a> of it is located in our oceans. Somewhat counterintuitively, this means that the vast majority of Earth’s topographic features - valleys, plains, mountains - are located under water as well. 

[caption id="attachment_1884693" align="alignnone" width="1024"]<img class="size-large wp-image-1884693" src="https://www.earth.com/wp-content/uploads/2020/10/awdfaw-1024x576.png" alt="ocean floor features" width="1024" height="576" /> [Image courtesy of the <a href="https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-floor-features" target="_blank" rel="noopener noreferrer">NOAA Office of Education</a>][/caption]Let's take a look at many prominent submerged features. Before taking the plunge, stop for a moment to examine the above diagram from the National Oceanic and Atmospheric Administration <a href="https://www.noaa.gov/education/resource-collections/ocean-coasts/ocean-floor-features" target="_blank" rel="noopener noreferrer">(NOAA).</a> It will serve as a convenient visual guide as we descend into the deep.
<h2>Continental Shelf</h2>
Continental shelves are large landmasses that surround each of the continents. This area is usually very shallow (comparatively), typically less than a few hundred feet. Continental shelves account for roughly 8% of all submerged features. Interestingly, continental shelves can drastically vary in size. 

For example, the continental shelf off the coast of Siberia extends 1,500 km (930 miles) into the Arctic Ocean. Conversely, off the coast of Africa, the continental shelf extends <a href="https://oceanexplorer.noaa.gov/edu/curriculum/section4a.pdf" target="_blank" rel="noopener noreferrer">only 10 km</a> (6 miles) into the Atlantic Ocean.

Continental shelves also serve as bastions of biological diversity. According to some estimates, about <a href="https://www.amnh.org/explore/ology/ology-cards/180-continental-shelf#:~:text=The%20shallow%2C%20sunlit%20waters%20of,found%20along%20the%20continental%20shelf." target="_blank" rel="noopener noreferrer">90% of the world’s fish</a> are found along the continental shelf. More interestingly, practically all of the world’s oceanic plants and most types of algae also live along the continental shelf. 

Perhaps the most famous of continental shelves is the <a href="https://oceanconservancy.org/protecting-the-arctic/take-deep-dive/bering-strait-gateway-arctic/" target="_blank" rel="noopener noreferrer">Bering Strait</a>. A mountain of evidence supports the hypothetical land bridge that anthropologists, geologists, and climate scientists believe allowed humans to cross over to North America from Asia some <a href="https://www.nps.gov/bela/learn/historyculture/other-migration-theories.htm#:~:text=As%20of%202008%2C%20genetic%20findings,Americas%20by%2016%2C500%20years%20ago." target="_blank" rel="noopener noreferrer">17,000 years ago</a>. 

Although the strait is now underwater, it is just barely submerged. The deepest section is less than 55m (180 feet) underwater. 

[caption id="attachment_1884694" align="alignnone" width="445"]<img class="wp-image-1884694 size-full" src="https://www.earth.com/wp-content/uploads/2020/10/continental-slope.jpg" alt="ocean floor features; continental slope diagram" width="445" height="210" /> [image via <a href="https://commons.wikimedia.org/wiki/File:Continentalmargin.jpg" target="_blank" rel="noopener noreferrer">Wikimedia Commons</a>][/caption]
<h2>Continental Slope</h2>
The end of the continental shelf is referred to as the continental slope. Geologists may refer to this location as the “seaward border of the continental shelf.” This ocean feature accounts for roughly 9% of the entirety of the ocean floor. 

On average, the ocean's continental slope descends into the sea at an angle of 4°. This may not seem like much, but over the course of 100km (60 miles) of the continental slope, the <a href="https://www.earth.com/earthpedia-articles/how-deep-is-the-ocean/">ocean depth</a> will increase by 70 km (43 miles)!

While the average slope of descent for continental slopes is 4°, some are much steeper. About 1,600 km (1000 miles) off the Cape of Good Hope, Africa, the continental slope drops some 20,000 feet over the course of only 16 km (10 miles). This corresponds to an average slope of 70°!
<h2>Abyssal Plain</h2>
Abyssal plains are the most common land feature on planet earth. They make up half of all of the ocean floor. The International Hydrographic Organization (<a href="https://iho.int/en/" target="_blank" rel="noopener">IHO</a>) defines abyssal plains as “extensive, flat, gently sloping or nearly level region at abyssal depths.” 

Abyssal depths are approximately 3,000-6,000 meters (10,000-20,000 feet). When the IHO says that these plains are flat - they’re not kidding. 

Compared to continental slopes, which fall roughly 2,800 meters (9,000 feet) for every 1,000 meters (3,000 feet), abyssal plains fall, on average, less than 1 meter per 1000 meters!

Abyssal plains are also the largest habitat on earth. Even so, extremely little is known about the organisms that inhabit this zone. 

This is mainly due to the stark lack of sunlight that penetrates to these depths. Sunlight only reaches roughly 1,000 meters (3,000 feet) down into the ocean. 

Considering that the abyssal plains exist, at the shallowest depth, at 3,000 meters, absolutely no sun reaches the floor here. 

[caption id="attachment_1884695" align="alignnone" width="1024"]<img class="wp-image-1884695 size-large" src="https://www.earth.com/wp-content/uploads/2020/10/bora-bora-685303_1920-2-1024x461.jpg" alt="ocean floor features" width="1024" height="461" /> [Image via Pixabay from <a href="https://pixabay.com/users/mariamichelle-165491/" target="_blank" rel="noopener noreferrer">Mariamichelle</a>][/caption]
<h2>Abyssal Hill</h2>
Abyssal hills are exactly what they sound like: relatively small hills that rise out of the <a href="https://www.earth.com/earthpedia-articles/what-is-the-hadal-zone/">abyssal plain</a>. These features comprise roughly 30% of the ocean floor. 

Typically, they rise no more than a few hundred meters above the abyssal plain and are less than 100 meters (300 feet) in width.
<h2>Seamount</h2>
Breaking down the term seamount we see two parts: sea and mount. The “sea” part references the fact that these features are under water. 

The “mount” part stems from “mountain.” Putting these two together, you have the definition of a <a href="https://oceanservice.noaa.gov/facts/seamounts.html" target="_blank" rel="noopener noreferrer">seamount</a>: an underwater mountain! Importantly, seamounts cannot break the water’s surface. 

[caption id="attachment_1884696" align="alignnone" width="1024"]<img class="size-full wp-image-1884696" src="https://www.earth.com/wp-content/uploads/2020/10/awf.jpg" alt="mariana trench" width="1024" height="683" /> [Image via Wikipedia. 1840489pavan nd / <a href="http://creativecommons.org/licenses/by-sa/4.0" target="_blank" rel="noopener noreferrer">CC BY-SA]</a>[/caption]
<h2>Ocean Trench</h2>
Deep, deep below the water’s surface lie vast, unexplored regions of the ocean floor: <a href="https://www.whoi.edu/know-your-ocean/ocean-topics/seafloor-below/ocean-trenches/" target="_blank" rel="noopener noreferrer">trenches</a>. These underwater canyons are the deepest spots in the ocean. In fact, from sea level, the surface of the earth extends further down than it does up! 

Mt. Everest is the tallest point on earth (elevation wise) at 8,848 meters (29,029 feet). In comparison, the Mariana Trench stretches down 11,034 meters (36,201 feet) below the surface. 

If we were to place Mt. Everest in the bottom of the trench, its summit would still be about 1.6 km (1 mile) below the surface!
<h2>Volcanic Island</h2>
Volcanic islands are usually referred to by their common name: islands. <a href="https://www.iwr.usace.army.mil/Missions/Coasts/Tales-of-the-Coast/Americas-Coasts/Hawaiian-Coast/Volcanic-Islands/" target="_blank" rel="noopener noreferrer">By definition</a>, seamounts that break the water's surface are called islands. In places like Hawaii, one can actually see the process of new land being formed as lava cools as it enters the ocean. 

<a href="https://www.nps.gov/havo/index.htm" target="_blank" rel="noopener noreferrer">Hawai’i Volcanoes National Park</a> is a prime example of this. Islands make up a relatively tiny fraction of the total area, but they are very numerous. The amount of islands in the world is practically impossible to estimate. 

Presently, the estimation ranges from about 5,000 oceanic islands to over 100,000. This figure also changes over geologic time. 

Islands tend to be somewhat unstable, and as global sea levels fluctuate over millions of years, new islands are exposed while others are submerged.

[Featured image via Pixabay from <a href="https://pixabay.com/users/mariamichelle-165491/" target="_blank" rel="noopener noreferrer">Mariamichelle</a>]

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Ocean Floor Features You Should Know About

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Nushagak Bay, a large estuary in southwest Alaska. Nushagak runs mainly north to south and exits in Bristol Bay, a large body of water in the Bering Sea.



"The bay is primarily fed by the Nushagak River, which begins in the Alaska Range and flows southwest approximately 450 km. The bay is also fed by several additional rivers including the Wood, Igushik, Snake and Weary rivers," says ESA.



"The dark colors of the Nushagak River are most likely due to tannins or lignins (chemical substances found in plants). Tannins and lignins from roots, leaves, seeds, bark and soil can leach into the water and give it a brown or even black colour. The sediments then flow southwards where it is mixed with the bluer waters of the bay."



Video/ Image Credit: ESA



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Nushagak Bay in southwest Alaska

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> (ACS) reveals that proteins on flu viruses are actually flexible, tilting and waving in a “breath-like” motion. According to the experts, these proteins could be used to better defend against the flu.



"The main antigenic targets of influenza virus are two surface glycoproteins, hemagglutinin (HA) and neuraminidase (NA). Whereas the structural and dynamical properties of both glycoproteins have been studied previously, the understanding of their plasticity in the whole-virion context is fragmented," wrote the researchers.



To investigate, the team conducted detailed simulations of the influenza A H1N1 virion, or the swine flu. The experts concluded that the visualizations show many new vulnerable states of flu viruses, which could improve future vaccines and antiviral drugs.



Video/ Image Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Flu viruses are more flexible than expected

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Lake Trasimeno, which is located west of Perugia in central Italy. It is the fourth largest lake in the country. While Trasimeno’s water level varies, it has a maximum depth of approximately six meters.&nbsp;



"In this Copernicus Sentinel-2 image, captured on 6 August 2022, the lake’s emerald green colour is likely due to the presence of phytoplankton. Streaks in the water, particularly visible in the west, indicate the presence of soil and sediments which have been stirred up by winds. Dark colored waters in the southern part of the lake indicate a presence of submerged and floating macrophytes (aquatic plants) as well as algae," says ESA.



"Surrounded by hills on three sides, Trasimeno is subject to heavy storms created by winds, especially from the north and west. There are three islets in the lake: Maggiore, Minore and Polvese (the largest). The lake’s shores are sparsely inhabited with only two popular villages: Castiglione del Lago and Passignano sul Trasimeno."



"Italy is experiencing its worst drought in 70 years which has affected drinking water supplies, hydroelectric power and agricultural production. High temperatures, hot winds and lack of rainfall are the main causes of drought in the Umbrian region which saw Lake Trasimeno’s drop 1.3 m, reaching the limit of the hydrometric zero in July 2022."



Video/Image Credit: ESA&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Lake Trasimeno in Central Italy

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Today's Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> describes a new self-powered nanosensor that can instantly detect mercury contamination with the tap of a finger.&nbsp;



The oxidized form of mercury can be harmful when it is ingested through contaminated water or food. This makes it necessary for experts to develop sensors that can quickly and accurately detect the presence of mercury.&nbsp;



Zong-Hong Lin and colleagues have now created a triboelectric nanosensor (TENS) that can detect mercury by simply by touching a sample. According to the researchers, their TENS could serve as the basis for similar devices to safely and remotely monitor other pollutants.



Video Credit: American Chemical Society&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Detecting mercury contamination with the tap of a finger

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Today’s Video of the Day from the <a href="https://www.acs.org/">American Chemical Society</a> explores the ability of salt to transform the way that foods and beverages taste. Salt is known to cover up undesirable flavors, such as bitterness in coffee or beer, but how exactly does sodium chloride change the taste of other compounds?



One previous study showed that, not only does salt suppress bitterness, but also enhances sweetness and sourness. Another study revealed that bitterness reduction by salt seems to be happening at the tongue receptor level as well as in the brain.&nbsp;



While it is known that salt taste is mediated by the presence of sodium channels in the form of taste buds, experts believe that there is also an unknown receptor responsible for how we taste salt that has not yet been identified.&nbsp;



Video Credit: ACS Reactions



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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How does salt makes things taste better?

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Santiago, the capital city of Chile. The city is located in the center of the Santiago Metropolitan Region, which has a population of about eight million people.&nbsp;



'The weather of Santiago resembles the Mediterranean climate with dry and warm summers with temperatures reaching up to 35°C (from October to March) and cool and humid winters that can drop to 0°C (from April to September)."



"The city lies in the centre of the country’s central valley around 80 km from the Pacific Ocean to the west and borders Argentina to the east. A tiny part of Argentina is visible in the top-right corner of the image where the mountain crest of the Andes Mountains acts as a divider between the two countries," says ESA.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Santiago, Chile in South America

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Spiral,Galaxy,,Illustration,Of,Milky,Way

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Astronomers at <a href="https://www.jhu.edu/">Johns Hopkins University</a> have created an interactive map of the universe, including the actual position and real colors of 200,000 galaxies. The map allows the public to access data that was previously only available to scientists.



The map was developed using data collected by the Sloan Digital Sky Survey. For over two decades, a telescope in New Mexico was aimed at slightly different locations to capture the night sky.&nbsp;



"Growing up I was very inspired by astronomy pictures, stars, nebulae and galaxies, and now it's our time to create a new type of picture to inspire people," said map creator Brice Ménard, a professor at Johns Hopkins. "Astrophysicists around the world have been analyzing this data for years, leading to thousands of scientific papers and discoveries. But nobody took the time to create a map that is beautiful, scientifically accurate, and accessible to people who are not scientists. Our goal here is to show everybody what the universe really looks like."



"In this map, we are just a speck at the very bottom, just one pixel. And when I say we, I mean our galaxy, the Milky Way which has billions of stars and planets. We are used to seeing astronomical pictures showing one galaxy here, one galaxy there or perhaps a group of galaxies. But what this map shows is a very, very different scale."



"From this speck at the bottom, we are able to map out galaxies across the entire universe, and that says something about the power of science."



The <a href="https://mapoftheuniverse.net/">interactive map</a> is available online, where it can be downloaded for free.



Video Credit: Johns Hopkins&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



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Interactive map of the universe includes 200,000 galaxies

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Lesotho: Africa's "Kingdom in the Sky" Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features northwest Lesotho in South Africa.



According to ESA, Lesotho is the only nation in the world that lies completely above 1,000 m in elevation. The country is famous for its tall mountains and narrow valleys, and is known as Africa's "Kingdom in the Sky."



Out of a population of around two million people, about 80 percent live in rural areas. More than 75 percent of these people are engaged in <a href="https://www.earth.com/news/climate-change-will-have-a-global-impact-on-agriculture/">agriculture</a>, including rainfed cereal production and animal grazing.&nbsp;



ESA reports that the country’s agricultural system faces a growing number of issues, with climate-related vulnerabilities such as drought, floods and extreme temperatures occurring more frequently. 



Diamonds are amongst the minerals found in the mountains. Indeed, Lesotho can truly be called the Kingdom in the Sky. Beautiful, culturally rich, safe, affordable, and easily accessible from Durban and Johannesburg, mountainous Lesotho is a vastly underrated travel destination. the Kingdom of Lesotho (Sotho: 'Muso oa Lesotho) is an enclaved country in southern Africa. It is just over 30,000 km2 (11,583 sq mi) in size and has a population of around 2 million.



Video Credit: ESA&nbsp;&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer 



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Lesotho: Africa's "Kingdom in the Sky"

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features Dublin, the capital and largest city of Ireland. Beyond its pub culture, Dublin is known as a modern culinary destination and a UNESCO City of Literature.



"Dublin is located near the midpoint of Ireland’s east coast in the province of Leinster. The city, which covers an area of around 115 square kilometers, is bordered by the Dublin Mountains, a low mountain range to the south, and is surrounded by flat farmland to the north and west," says ESA.



"The city straddles the River Liffey, which rises in the Wicklow Mountains and flows around 80 kilometers eastwards through the city of Dublin, in which it is canalised and bordered with quays. It then empties into Dublin Bay, an arm of the Irish Sea."



Dublin has an abundance of green spaces, including one of the largest enclosed public parks in any European capital city. Phoenix Park, which was originally formed as a royal hunting park in the 1660s, includes 707 hectares of green space.



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The city of Dublin on Ireland's east coast

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Today's Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the province of Zaragoza in northeast Spain. The image was captured by the Copernicus Sentinel-2 mission.



"Together with the provinces of Huesca and Teruel, Zaragoza formed the old kingdom of Aragon. Its capital, also called Zaragoza (not visible in this image) is home to around half of Aragon’s population," says ESA.



"The Ebro River can be seen winding its way through the province from west to east in this image. Between its source in the Cantabrian Mountains in the northwest and its delta on the Mediterranean coast, the Ebro River is fed by more than 200 tributaries as it flows 910 km across much of northern Spain."



Since rainfall is very scarce in this region, irrigation in the Ebro basin is critically important. In the valleys surrounding the Ebro River, many fields are used for growing crops such as corn, wheat, and barley.



Video/ Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The province of Zaragoza in northeast Spain

[sendtonews key="oL4FnPTGCV-2384527-12187" type="single"] Today's Video of the Day from the...

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> reveals the evolution of the Columbia Glacier in southeastern Alaska. Columbia is among the fastest shrinking glaciers in the world, and the video documents its rapid retreat over the years.&nbsp;



Columbia Glacier is a large, multi-branched calving glacier that flows out of the Chugach Mountains to the Prince William Sound.&nbsp;



According to USGS, Columbia had a long history of stability prior to 1980, with a length 41 miles, and small, short-lived advances or retreats.



In the years since 1980, however, satellite images have captured Columbia’s alarming retreat. By using false-color images, scientists can distinguish between snow and ice, open water, vegetation, and rocky debris on the glacier’s surface.



The series of false-color images featured in today's video were acquired over the span of 35 years. You can see that by 2021, the glacier’s main branch had retreated about 15 miles from its initial position.



The Columbia Glacier has also lost more than 50 percent of its volume, mostly due to calving. <a href="https://www.earth.com/video/nasa-reveals-3d-visual-of-an-atmospheric-river/">NASA</a> reports that while climate change likely started the retreat, mechanical processes kept the disintegration going.



The NASA images are provided by Jesse Allen, Robert Simmon, Joshua Stevens, and Lauren Dauphin using data from Landsat satellites, from the U.S. Geological Survey, and data from MODIS on NASA’s Terra satellite. The structure of Columbia’s moraine played a large role in the stability of the glacier before 1980. 



Like other tidewater glaciers, the Columbia built up a moraine over time, and the mixture of ice and rock functioned like a dam keeping out the sea. It was supported on one end by the shoreline and by the underwater terminal moraine at the other.



Video Credit: NASA Earth Observatory/&nbsp; NASA’s Scientific Visualization Studio



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The rapid retreat of the Columbia Glacier

[sendtonews key="0879czfG3k-1785905-12187" type="single"] Today’s Video of the Day from NASA...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> features the Pyrenees Mountains, which form a natural boundary between France and Spain in southwest Europe.



The mountain range is 430 kilometers in length. It stretches from the Mediterranean Sea on the east to the Atlantic Ocean on the west.



At an elevation of 3404 meters, Pico de Aneto is the highest mountain peak in the Pyrenees, and the third-highest peak in Spain. Pico de Aneto is located in the Posets-Maladeta Natural Park, which spans more than 82,000 acres.&nbsp;



"Geological studies have revealed that the Pyrenees Mountains have been around for longer than the Alps, with their sediments first deposited in coastal basins during the Paleozoic and Mesozoic eras," reports ESA.



"The entire mountain range formed due to the upwelling of large sedimentary rocks by the collision of the Iberian and the Eurasian plate around 100 to 150 million years ago, followed by intense erosion from ice and water."



The western Pyrenees receive more precipitation due to moisture blowing in from the Atlantic Ocean. The mountain range contains many lakes, several small glaciers, and some of the highest waterfalls in Europe.



Video &amp; Image Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The Pyrenees Mountains in southwest Europe

[sendtonews key="6HyfrAJTBI-1831843-12187" type="single"] Today’s Video of the Day from the...

Earth,Like,Exoplanet,3d,Render

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Today's Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes two exoplanets that are orbiting a star 218 light-years away. A team of researchers led by the University of Montreal has found evidence that these planets are "water worlds."



The experts used data from NASA’s Hubble and Spitzer Space Telescopes. They discovered that exoplanets Kepler-138 c and Kepler-138 could be composed largely of water.



"We previously thought that planets that were a bit larger than Earth were big balls of metal and rock, like scaled-up versions of Earth, and that's why we called them super-Earths," explained study co-author Björn Benneke.&nbsp;



"However, we have now shown that these two planets, Kepler-138 c and d, are quite different in nature and that a big fraction of their entire volume is likely composed of water. It is the best evidence yet for water worlds, a type of planet that was theorized by astronomers to exist for a long time."



Video Credit: NASA Goddard



Image Credit: NASA, ESA, and Leah Hustak (STScI)



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Two distant planets may be "water worlds"

[sendtonews key="QIoVYJqRBi-2434608-12187" type="single"] Today's Video of the Day from NASA...

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Satellites reveal how Earth's systems are interconnected Today’s Video of the Day from <a href="https://www.nasa.gov/goddard">NASA Goddard</a> describes Earth’s interconnected systems, and how this network is affected by rising temperatures.&nbsp;



During 2020, average global temperatures matched the hottest year on record. The hurricane season was also record-breaking, with many of the storms intensifying at extraordinary speeds. Hot water in the ocean is fuel for hurricanes. The satellite data shows that it's all one interconnected system showing how Satellites reveal how Earth's systems are interconnected.



According to NASA, dust swept up from Northern Africa plays a major role in the formation of hurricanes, and is also a key source of fertilization in the Amazon rainforest. As a result of<a href="https://www.earth.com/news/seagrass-wasting-disease-is-fueled-by-climate-change/"> climate</a> change, dust plumes are expected to decline, which will have an effect on vegetation far away.&nbsp;



Images from Earth-observing satellites show how the world’s plant life is affected by natural disasters, fires, and deforestation. Satellites also reveal how widespread changes in vegetation impact waterways,&nbsp; the climate, air quality. Satellites communicate by using radio waves to send signals to the antennas on the Earth. "Earth From Space" is a groundbreaking two-hour special that reveals a spectacular new space-based vision of our planet. 



Video Credit: NASA Goddard&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites reveal how Earth's systems are interconnected

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Today’s Video of the Day from the <a href="https://welcome.miami.edu/">University of Miami</a> Rosenstiel School of Marine and Atmospheric Science explores how changes in water temperatures have affected tiger shark habitats and movements in the North Atlantic Ocean. The study reveals that rising temperatures have caused the sharks to shift toward the poles over the past 40 years.



“Tiger shark annual migrations have expanded poleward, paralleling rising water temperatures,” explained study lead author Neil Hammerschlag. “These results have consequences for tiger shark conservation, since shifts in their movements outside of marine protected areas may leave them more vulnerable to commercial fishing.”



The researchers analyzed nine years of tracking data from satellite-tagged tiger sharks, combined with four decades of conventional tag and recapture data provided by National Oceanic and Atmospheric Administration (NOAA) Cooperative Shark Tagging Program.



The experts found that during the last decade of record heat, for every one-degree Celsius increase in water temperatures, tiger sharks migrated further poleward by over 400 kilometers. They also migrated two weeks earlier than usual to waters off the northeastern coast of the United States.



“Given their role as apex predators, these changes to tiger shark movements may alter predator-prey interactions, leading to ecological imbalances, and more frequent encounters with humans,” concluded Professor Hammerschlag.



Video Credit: University of Miami Rosenstiel School of Marine and Atmospheric Science



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Tiger sharks are shifting poleward as temperatures rise

Today’s Video of the Day from the University of Miami...

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> is focused on the melt ponds that emerge during the spring and summer on the Greenland Ice Sheet, which is the largest ice mass in the northern hemisphere.



"Melt ponds are vast pools of open water that form on both sea ice and ice sheets and are visible as turquoise-blue pools of water in this Copernicus Sentinel-2 image," says ESA.



"When snow and ice melts atop glaciers, water flows in channels and streams and collects in depressions on the surface. These melt ponds can speed up the melting of the surrounding ice since they greatly reduce the ice’s ability to reflect sunlight."



"This can create a positive feedback where an increasing number of melt ponds absorb more heat which causes ice cover to melt even faster."



According to ESA, Greenland has been hit with a late-season heatwave that began in early September. This caused the type of melt event that usually occurs in the middle of summer.



"In a recent paper published in Nature Climate Change, scientists found that major sea-level rise from the melting of the Greenland ice cap is now ‘inevitable’ even if the burning of fossil fuels were to halt overnight," says ESA. "Using satellite observations of Greenland ice loss and ice cap from 2000 to 2019, the team found the losses will lead to a minimum rise of 27 cm regardless of climate change."



Video Credit: ESA&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Melt ponds on the Greenland Ice Sheet

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes a new map of Mars that is providing insight into the planet’s watery past. The map also reveals where future missions could safely land on Mars.&nbsp;



The map has been created over the last decade using observations of water-rich rocks and mineral deposits. The images were captured by ESA’s Mars Express and NASA’s Mars Reconnaissance Orbiter.



"A big surprise is the prevalence of these minerals, with the map revealing hundreds of thousands of water-affected locations in the oldest parts of the planet," says ESA. "The new data will help answer exciting questions about Mars’ climate history, whether water was globally persistent or confined to short, intense episodes, and whether the conditions were ever suitable for life."



"Specifically, the map shows the locations and abundances of aqueous minerals. These are from rocks that have been chemically altered by the action of water in the past, and have typically been transformed into clays and salts."



According to John Carter of the Institut d’Astrophysique Spatiale (IAS), our collective understanding of Mars has been oversimplified. He explained that planetary scientists have tended to think that only a few types of clay minerals on Mars were created during its wet period, then as the water gradually dried up, salts were produced across the planet.



The new map shows that the composition of Mars is much more complicated than what we thought. For example, while many salts formed after Martian clays, there are some salts that are presumed to be older than some of the clays.&nbsp;



“The evolution from lots of water to no water is not as clear cut as we thought, the water didn’t just stop overnight. We see a huge diversity of geological contexts, so that no one process or simple timeline can explain the evolution of the mineralogy of Mars. That’s the first result of our study. The second is that if you exclude life processes on Earth, Mars exhibits a diversity of mineralogy in geological settings just as Earth does,” said Carter.



Video Credit: ESA



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

The history of Mars is much more complex than we thought

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Today's Video of the Day from the <a href="https://www.stowers.org/">Stowers Institute for Medical Research</a> describes how cavefish adapted to a sedentary lifestyle over tens of thousands of years. 



The experts found that the muscle metabolism of cavefish has been genetically reprogrammed over time. As a result, the animals have experienced major changes in their morphology and behavior. Despite these changes, however, the cavefish remain healthy and fit.



The research may provide new clues about the evolutionary consequences of prolonged physical inactivity in humans.&nbsp;



“It’s no surprise that people are moving less and less as technology has advanced,” said Rohner. “With cavefish, we have a unique system where we can study what might happen if people remained couch potatoes over very, very long periods of time.”



Video Credit: Stowers Institute for Medical Research



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Cavefish are healthy despite their sedentary lifestyle

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Today’s Video of the Day from <a href="https://earthobservatory.nasa.gov/">NASA Earth Observatory</a> some of the most incredible waves in the world, as seen by Landsat satellites.



"With more than 370,000 miles of coastline on Earth, there are plenty of places where epic waves build up, curl over, and hurtle toward the shore.- much to the thrill of surfers," says NASA. "There are some places where these waves are so magnificent that they can be seen from space."



"With the broad perspective of satellites, we can see how these iconic waves develop into the world’s tallest, longest, fastest, and heaviest."



Video Credit: NASA Earth Observatory&nbsp;



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By <a href="mailto:csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Editor



Check us out on <a href="https://www.earth.com/earthsnap/">EarthSnap</a>, a free app brought to you by Eric Ralls and Earth.com.

Satellites capture the world's biggest and fastest waves

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Today’s Video of the Day from the <a href="https://www.esa.int/">European Space Agency</a> describes why satellite images and measurements of our planet have become "essential to our survival, offering a new outlook of our world."&nbsp;



Rising sea levels pose one of the biggest societal threats associated with climate change. According to ESA, satellite altimeter missions such as Copernicus Sentinel-6 are essential in monitoring global and regional changes in sea level.



"Unbeknown to many, the island of Crete, Greece, plays an important role in the Copernicus satellite altimetry constellation and on an international stage," reports ESA.



"Satellite altimetry data have to be continuously monitored at the ESA’s Permanent Facility for Altimetry Calibration where different techniques have pioneered the use of transponders to provide the best measurements to validate satellite altimeters in space soon after launch."



Dr. Craig Donlon explains that, by understanding planet Earth through satellite measurements, we are able to find evidence of change.&nbsp;



Video Credit: European Space Agency&nbsp;



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By <a href="http://csexton@earth.com">Chrissy Sexton</a>, <a href="https://www.earth.com/staff/">Earth.com</a> Staff Writer

Satellites have become essential to our survival

[sendtonews key="761m2QQvR1-2035772-12187" type="single"] Today’s Video of the Day from the...