Humanity is causing a mass extinction of sea life unprecedented by any in the fossil record, targeting larger species in a way never before seen in history, according to scientists.
In a new study conducted by Stanford University, researchers analyzed data on modern marine organisms to determine how body size and ecological traits were impacted over time.
"We've found that extinction threat in the modern oceans is very strongly associated with larger body size," says paleobiologist Jonathan Payne, a member of the Stanford study. "This is most likely due to people targeting larger species for consumption first."
Payne and his team investigated the current state of the ocean’s health by pulling data from 2,497 extinct and living marine species in the fossil record over the last 550 million years, as well as modern ocean industry statistics, says Science Magazine. By comparing the extinction threat modern marine genera face to their ancient counterparts, the researchers discovered a strong association between the modern extinction threat and body size.
"What our analysis shows is that for every factor of 10 increase in body mass, the odds of being threatened by extinction go up by a factor of 13 or so," says Payne. "The bigger you are, the more likely you are to be facing extinction."
In her coverage of the report, Maddie Stone, former environmental scientist and now a writer for Gizmodo, points out the there are some flaws to the Stanford team’s analysis. By only looking at extinction risks assessed by the International Union for the Conservation of Nature (IUCN), Stone argues scientists don’t have enough data to perform a proper threat assessment on many existing marine species. Additionally, Stone notes a flaw in the omission of corals from the study, which serve as a habitat for roughly a quarter of all marine life and therefore have a great impact on the health of the oceans overall.
Mark Eakin, a biological oceanographer with NOAA who was not involved with the study, expressed similar dissatisfaction with the scope of the Stanford team’s analysis.
“This study largely does not address the impact we are having on ocean ecosystems through global climate change,” Eakin reported to Gizmodo. “Our increases in atmospheric CO2 will add to the impacts found by the authors to broaden our species’ destructive reach.”
But according to scientists, there is still hope to save the ocean’s largest marine animals. Douglas McCauley, another author of the Stanford study, told The Guardian that an increasing trend for governments to provide large protected marine areas for larger animals could make a difference in threats of extinction.
“Recently Obama created the world’s largest protected [marine] area in Papahanaumokuakea, a protected area just over a million square [kilometers] in size,” McCauley said. “This is really good news as parks of this size will indeed provide meaningful protection for large vulnerable animals we highlight as being at risk.”
“We’re lucky in many ways,” said Malin L. Pinsky, a marine biologist at Rutgers University and a contributor to the Stanford report, reports The New York Times. “The impacts are accelerating, but they’re not so bad we can’t reverse them.”