Species that depend on the sea are reacting more quickly to global warming than land-based life, according to a study in scientific journal Nature Climate Change, with implications for fisheries and food supplies.
Areas occupied by marine species including fish, corals and plankton are moving by an average of 72 kilometers (45 miles) a decade, typically toward the poles, the study by researchers at 17 institutions in 8 countries said today. That’s more than 10 times the 6.1 kilometer rate that land creatures are shifting.
Marine environments face a range of changes brought on by the rising carbon emissions that scientists blame for global warming. Arctic sea ice is melting at record rates, while the carbon dissolved in the oceans is causing acidity to rise, harming corals and shellfish. The latest analysis will have implications for fisheries, an author of the paper said.
“If the food a fish is eating is moving at a different pace, then the fish and their prey aren’t arriving at the same point at the same time,” Pippa Moore, a lecturer in aquatic biology at Aberystwyth University in Wales said in a telephone interview. “That has implications for the abundance of species and it will undoubtedly affect our food supplies and the species we’re used to seeing at our shores.”
The researchers compiled data from 208 prior studies that examined 857 species. They found species of phytoplankton are shifting their ranges at almost 470 kilometers a decade and bony fish are moving at 278 kilometers every 10 years. Less mobile species such as corals are moving more slowly, Moore said. The study included seabirds, seals and polar bears in the assessment as they live in a marine environment and feed mostly on sealife.
Researchers also uncovered shifts in seasonal behavior, or phenology, such as breeding, egg-laying and migration. Marine life is displaying behavior typical of both spring and summer about 4.4 days earlier a decade. That compares with estimates of 2.3 to 2.8 days for land-based creatures, the researchers said.
“This is the first comprehensive documentation of what is happening in our marine systems in relation to climate change,” Camille Parmesan, a co-author of the report and professor of oceans at Plymouth University in southwestern England, said in an e-mailed statement. “The changes that are occurring on land are being matched by the oceans. And far from being a buffer and displaying more minor changes, what we’re seeing is a far stronger response from the oceans.”