Three important coral habitats are vanishing

A new study from the University of São Paulo has concluded that the climate crisis will lead to detrimental changes in the stony coral habitats of the tropical Atlantic. The research, published by Frontiers, concludes that the loss of such species could have a devastating chain reaction of consequences for marine ecosystems unless urgent action is taken.

The researchers projected current and future distributions of three “ecosystem engineer” corals: Mussismilia hispida, Montastraea cavernosa, and the Siderastrea complex. Each species deposits calcium carbonate, an essential compound for the marine ecosystem maintenance.

“Coral reefs provide essential ecosystem services such as food provision, coastal protection, and nutrient cycling, that benefit millions of people – including those who live far from any coral reef,” stated study lead author Silas Principe. “If species that are important in structuring the coral reefs are lost, the provision of all those services is consequently also threatened.”

Human activity has harmed coral habitats worldwide; intense pollution, fisheries, and tourism all contribute to the loss of coral cover. The climate crisis is yet another factor. Climate change leads to key coral species moving to temperate waters at higher latitudes and may have cascading effects on marine wildlife communities.

The researchers collected data on the three reef types and used distribution models to model their suitability on their current habitat. They also used future projections based on three scenarios – pessimistic, optimistic, and moderate. 

Tragically, decreased abundance of stony corals is expected under each scenario. The Brazilian coast will be particularly affected, as it contains fewer habitat-building coral species.

The researchers urge conservation efforts to focus within the Abrolhos region, northeast coast of Brazil, western Caribbean, and the Gulf of Mexico. “We show that important reef builder species of the Atlantic will face shifts in its distribution due to climate change,” said Principe.

“Certain areas, such as the Abrolhos region in the coast of Brazil, will completely lose at least one of its species in any of the future scenarios. Major areas in the Caribbean will also lose species in the future, although in the coast of Africa some species may expand their current range.”

However, there is still hope for Atlantic stony corals. “Although our results predict major negative impacts on Atlantic shallow reefs, we also identified several areas where none or fewer changes are predicted,” said Principe. “Managers and policymakers can use this to support the planning process of conservation areas.” 

“Researchers and conservationists can use these results to focus research efforts on the so-called ‘refuge areas’ that may constitute safe areas for coral species in the future.”

The study is published in the journal Frontiers in Marine Science.

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By Calum Vaughan, Earth.com Staff Writer