One In Five Giant Marine Species Will Become Extinct Within Century, Scientists Predict
A significant number of sharks, whales and sea turtles could become extinct within the next 100 years, subsequently having a knock-on effect on marine ecosystems, a new study suggests.
Researchers from Swansea University examined traits of marine megafauna species – defined as the largest animals in the oceans, with a body mass that exceeds 45kg – to see what sort of effects their extinction would have on marine life.
As well as estimating almost one in five (18%) of marine megafauna would become extinct in the next century if current trends continue, the researchers also found this would translate to an 11% loss of the extent of ecological functions.
Researchers also envisioned a worst-case scenario in which up to 40% of marine megafauna species could disappear if all threatened species currently listed on the IUCN Red List go extinct. If this was to happen, the extent of ecological functions could be reduced by almost half.
Ultimately, this is because such species serve key roles in ecosystems, such as transporting nutrients across habitats, connecting ocean ecosystems, physically modifying habitats, and consuming large amounts of biomass.
Dr John Griffin, co-author of the study, said in a statement:
If we lose species, we lose unique ecological functions. This is a warning that we need to act now to reduce growing human pressures on marine megafauna, including climate change, while nurturing population recoveries.
Publishing their findings in the journal Science Advances, the researchers predicted that sharks would be ‘the most affected’, with losses of functional richness ‘far beyond those expected under random extinctions’. Other species at risk include a variety of rays, whales, seals, sea cows, polar bears, sea turtles, penguins, and octopuses.
Some of the specific traits of these animals leave them particularly exposed to the risk of extinction, with the study noting that great white sharks and whale sharks are vulnerable because they are ‘highly migratory’ and are therefore known to travel across large areas of the ocean, ultimately increasing their risk.
Dr Catalina Pimiento, who led the research from Swansea University, said:
Our previous work showed that marine megafauna had suffered an unusually intense period of extinction as sea levels oscillated several million years ago. Our new work shows that, today, their unique and varied ecological roles are facing an even larger threat from human pressures.
As a result, not only would we be losing some incredible animals if they were to go extinct, but we would also be losing a vital part of our marine ecosystem.
If you have a story you want to tell, send it to UNILAD via [email protected]