As the world continues to warm and natural habitats change, many species are expected to be displaced, both on land and at sea,media New Atlas reported. Scientists have studied data on benthic shellfish for more than half a century and found evidence of a destructive feedback loop in which generations of marine life are trapped in warm areas that threaten their survival.
The study, conducted at Rutgers University, sheds some counterintuitive questions about the migration of marine species. Many creatures cope with warming waters by seeking refuge in cooler areas, but scientists have found that some species do the opposite, calling the phenomenon “wrong migration.”
These species include scallops, mussels, clams and round clams. The team noted that these shellfish are a valuable resource for the shellfish industry and concluded from data from more than 50 species on the northeast coast of the United States over 60 years. About 80 per cent of the species studied can no longer be found in traditional habitats, but instead appear in shallower, warmer waters.
“These deeper, colder outer shelf waters should provide a refuge from warming, so it’s inexplicable that species distribution shrinks to shallower waters,” said Heidi Fuchs, lead author of the study.
According to scientists, warmer seawater is causing these species to lay their eggs early in the spring and summer seasons. This exposes scallop seedlings to wind patterns and currents that they do not normally experience, which carry weak swimmers into areas they do not normally live in. Once there, they are unlikely to survive, but scallops that survive and continue to grow become part of a destructive feedback loop that in turn causes their offspring to lay their eggs earlier and then cycle back and forth.
Although the study looked only at benthic invertebrates in one general location, the results were consistent with trends observed in animals affected by climate change in other habitats. Sometimes referred to as the “extinction elevator” phenomenon, animals such as birds and butterflies are driven to higher and higher altitudes to escape rising temperatures until they are no longer found in the area where they originally lived.
The study was published in the journal Nature Climate Change.