Atlantic walrus are at high risk of extinction

The Atlantic walrus faces unprecedented threats due to the relentless cycle of climate change and historical human exploitation, resulting in isolated and diminutive populations, warns a frightening study conducted by Lund University in Sweden.

The present-day population of the Atlantic walrus is in a precarious state, grappling with an array of hazards that have intensified due to soaring Arctic temperatures and decades of rampant human exploitation.

Unraveling the past of Atlantic walrus

The research team embarked on an exploration of how walrus adapted to historical climate change patterns. Employing revolutionary techniques in ancient genomics, they managed to extract, sequence, and analyze ancient genetic data from teeth and bones found in the Arctic’s frost-bound archaeological sites.

By integrating these findings with contemporary genetic samples, the team then reconstructed the genetic diversity modifications of the Atlantic walrus during previous global warming cycles.

Peter Jordan, Professor of Archaeology at Lund University, remarked, “Arctic warming has led to a surprisingly high genetic separation of local walrus stocks due to their very specific habitat requirements. This has precipitated the swift distribution, isolation, and, often, extinction of various walrus populations.”

Survival amidst ice ages

The last Ice Age, which climaxed between 27,000 and 19,000 years ago, subsumed the Arctic under massive glacial sheets. This compelled marine mammals, including walruses, to migrate southward to regions with more open water and ice floes.

Walruses managed to survive in select southern Atlantic areas, and with the subsequent rise in temperatures, they rapidly shifted northwards again. This climate-induced relocation resulted in local walrus populations undergoing extensive genetic differentiation.

Human impact and exploitation

Furthermore, the past millennium witnessed the Atlantic walrus facing extinction events from many angles, mainly due to human hunting and commercial pursuits.

Norse settlers’ expansion into Iceland and the North Atlantic in search of valuable walrus ivory and industrial-scale walrus population culling in more modern times have severely affected their populations.

Diminishing genetic diversity

Atlantic walrus stocks now exhibit a mere fraction of their former genetic diversity, leaving them increasingly susceptible to burgeoning pressures such as rapid ice loss, disruptions due to Arctic shipping, resource extraction, and expanding tourism.

“The receding Arctic sea ice will force the already depleted walrus stocks into smaller, more isolated refuges, heightening their vulnerability to stressors like shipping, resource extraction, and mass tourism due to the heightened genetic isolation and reduced connectivity,” Professor Jordan elucidates.

Conserving the Atlantic Walrus

This research emphasizes the crucial need for revisiting conservation objectives for species inhabiting the rapidly transforming Arctic marine ecosystems. As Peter Jordan concludes, “Our findings emphasize the immediate need for re-evaluating conservation strategies for species inhabiting the swiftly altering Arctic marine landscapes.”

In summary, the study accentuates the escalating danger to the last standing Atlantic walrus stocks, urging a reevaluation of conservation efforts and drawing attention to the complex interplay of climate change and human activities that are driving this species towards isolation and possibly, extinction.

The synthesis of ancient and modern genetic data sheds light on the longstanding impacts of climate variations on the Atlantic walrus, providing a dire warning and a call to action to safeguard the remaining populations against the multifaceted threats they are confronting.

More about the Atlantic walrus

The Atlantic walrus (Odobenus rosmarus rosmarus), an integral component of Arctic marine ecosystems, finds itself amidst a relentless battle for survival. As we learned above, they are in a battle for survival against the mounting pressures of climate alterations and historical human encroachments.

Physical description

The walrus is renowned for its distinctive physical attributes which are well adapted to the harsh and unforgiving environment of the Arctic and Subarctic regions.

Size and weight

Adult males typically weigh between 900 to 1,400 kilograms, while females are generally smaller, weighing between 560 to 880 kilograms. The body length of adult males ranges from 2.2 to 3 meters, with females measuring approximately 2 to 2.5 meters.

Tusks

One of the most distinctive features of the Atlantic walrus is its long, prominent tusks, which are elongated upper canine teeth.

Both males and females possess tusks, with those of males being larger and longer, sometimes reaching lengths of up to 1 meter. Tusks are used for various purposes including fighting, dominance display, cutting through ice, and aiding in pulling themselves out of the water onto ice.

Vibrissae (Whiskers)

Walrus have a set of highly sensitive whiskers, or vibrissae, which are used to detect prey on the ocean floor. These whiskers are attached to muscles and are rich in nerves, making them highly sensitive to stimuli, aiding in the location of food such as clams and other benthic invertebrates.

Blubber

The walrus possesses a thick layer of blubber, sometimes up to 15 cm thick, which serves multiple purposes. It acts as an insulator against the extreme cold of its environment, provides buoyancy while swimming, and serves as an energy reserve during periods of food scarcity.

Pectoral flippers

They have large, strong pectoral flippers that aid in swimming. These flippers allow the walrus to steer and generate propulsion in the water, and they also use them to crawl on land or ice.

Skin and coloration

The skin of the Atlantic walrus is tough and wrinkled and can be up to 4 cm thick. The coloration of the skin is generally brownish, but it can appear reddish or pinkish when the walrus is warm due to blood flow to the skin’s surface to release heat.

Eyes and ears

Walruses have relatively small eyes adapted to the high-latitude environment, and they possess external ear flaps which can be closed while diving to prevent water entry.

These physical attributes, along with their unique behavioral adaptations, allow the Atlantic walrus to survive and thrive in one of the most extreme and unforgiving environments on our planet.

Atlantic walrus reproduction

The reproduction process of the Atlantic walrus is a fascinating aspect of its biology, adapted to its unique Arctic and Subarctic environments.

Mating season

Atlantic walruses typically enter their mating season from December to March, when males engage in competitive displays and physical confrontations to establish dominance and secure mating rights with females.

Courtship and mating

During courtship, male walruses utilize vocalizations, referred to as “knocking” or “tapping,” to attract females, and they employ their tusks in aggressive encounters with rivals. Once a male successfully secures a mate, copulation occurs in the water.

Gestation and birth

After successful mating, female walruses undergo a gestation period that lasts about 15 to 16 months, which includes a delayed implantation period where the fertilized egg does not immediately implant in the uterus.

This adaptive strategy ensures the birth of the calves aligns with optimal environmental conditions. Females give birth to a single calf, typically between May and June, although twins can occur on rare occasions.

Calf dependency and weaning

The newborn calf, weighing around 45 to 75 kilograms, exhibits a strong dependency on its mother, relying on her for nutrition and protection. The mother walrus nourishes her calf with rich, fatty milk, allowing it to gain weight rapidly.

Although calves begin to consume solid food at around five months of age, they continue to nurse and remain close to their mothers for over two years, until the weaning process completes.

Sexual maturity

Atlantic walruses generally reach sexual maturity at around six to seven years of age for females and ten years for males. However, males are usually not successful in securing mates until they attain physical maturity and sufficient body size, typically around 15 years of age.

The intricate reproductive behaviors and strategies of the Atlantic walrus, including delayed implantation and prolonged calf dependency, reveal the species’ adaptations to the harsh and variable conditions of its Arctic habitat. These adaptations play a crucial role in the survival and perpetuation of this remarkable species in its challenging environment.

Diet

The Atlantic walrus predominantly forages in shallow marine areas and pursues a diet consisting mainly of benthic invertebrates.

Clams and mollusks

The walrus primarily consumes clams and other mollusks, utilizing its highly sensitive vibrissae (whiskers) to locate prey on the sea floor. It employs a unique suction technique to extract the soft parts of the clams, discarding the shells.

Additional prey

While clams are the dietary staple, the walrus also consumes a variety of other marine organisms. It eats worms, gastropods, sea cucumbers, and other benthic invertebrates available in its habitat, showcasing some dietary diversity.

Occasional predation

In some instances, the Atlantic walrus also preys on fish, seals, and even seabirds when benthic invertebrate resources are scarce, demonstrating opportunistic feeding behavior to adapt to the availability of food resources.

Foraging behavior

Typically, the Atlantic walrus embarks on foraging dives that can last up to 30 minutes and reach depths of up to 80 meters, although most dives are usually shorter and shallower. During these dives, it uses its powerful forelimbs to excavate the seabed, stirring up the sediment to expose hidden prey.

Energy requirement

Due to its large body size and high energy expenditure, especially during swimming in cold waters, the Atlantic walrus needs to consume a significant amount of food. It is estimated that an adult walrus must eat around 3% to 6% of its body weight daily to meet its energy requirements.

The diet of the Atlantic walrus, primarily revolving around benthic invertebrates, is a crucial component of its biology, allowing it to thrive in the unique and harsh environments of the Arctic and Subarctic regions. The availability and abundance of its preferred prey significantly impact its distribution, behavior, and overall well-being in its natural habitat.

Conservation and protection

As mentioned in the Lund University study above, conservation and preservation of the Atlantic walrus needs to become an urgent priority for humanity. The current system involves multifaceted strategies aimed at mitigating threats and ensuring the survival and well-being of this species in its natural habitat.

Legal protections

Several countries within the range of the Atlantic walrus have enacted legal protections to safeguard this species. Regulations typically prohibit or strictly regulate hunting, thereby reducing human-induced mortality. The enforcement of these laws is crucial to curb illegal hunting and ensure compliance with conservation measures.

Habitat protection

Conservation organizations and governments are working to protect crucial walrus habitats, including breeding and feeding grounds. The establishment of marine protected areas helps in preserving the essential habitats of the Atlantic walrus, mitigating the impacts of human activities such as shipping and oil exploration.

Climate change mitigation

Given the significant impact of climate change on the Atlantic walrus’s habitat, efforts to combat global warming are integral to its conservation. International initiatives aiming at reducing greenhouse gas emissions are crucial to slow the pace of Arctic warming and sea ice loss.

Monitoring and research

Ongoing monitoring and research are being conducted to understand the population dynamics, health, and behavior of the Atlantic walrus better. The collection of robust scientific data is vital to inform conservation strategies and adapt them to the changing needs of the species.

Public awareness and education

Conservation organizations are actively promoting public awareness and education about the Atlantic walrus. Raising awareness about the plight of this species and its importance in the Arctic ecosystem can garner public support for conservation measures and foster a sense of stewardship for the environment.

International cooperation

Walrus conservation necessitates collaboration among the countries within its range. International partnerships facilitate the sharing of knowledge, resources, and expertise, enabling the development and implementation of cohesive and effective conservation strategies across borders.

Sustainable resource management

Balancing the need for resource extraction with conservation is crucial. Implementing and enforcing sustainable resource management practices can help minimize the negative impacts of human activities such as fishing and oil drilling on the Atlantic walrus and its habitat.

In summary, conservation of the Atlantic walrus is paramount, requiring a comprehensive and integrated approach that addresses both direct and indirect threats to the species. The synergy of legal protections, habitat conservation, climate change mitigation, research, public awareness, international cooperation, and sustainable resource management is pivotal to ensure the long-term survival and prosperity of the Atlantic walrus in a rapidly changing Arctic environment.

The full study was published in the journal Proceedings of the Royal Society B Biological Sciences.

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