Movement of marine life follows speed and direction of climate change

A press release from Princeton University: Scientists expect climate change and warmer oceans to push the fish that people rely on for food and income into new territory. Predictions of where and when species will relocate, however, are based on broad expectations about how animals will move and have often not played out in nature. New research based at Princeton University shows that the trick to more precise forecasts is to follow local temperature changes.

The researchers report in the journal Science the first evidence that sea creatures consistently keep pace with "climate velocity," or the speed and direction in which changes such as ocean temperature move. They compiled 43 years of data related to the movement of 128 million animals from 360 species living around North America, including commercial staples such as lobster, shrimp and cod. They found that 70 percent of shifts in animals' depth and 74 percent of changes in latitude correlated with regional-scale fluctuations in ocean temperature.

New research based at Princeton University shows that the trick to predicting when and where sea animals will relocate due to climate change is to follow the pace and direction of temperature changes, known as climate velocity. The researchers compiled 43 years of survey data on the movement of 128 million animals living around North America. Shifts in the animals' depth and latitude correlated with regional-scale fluctuations in ocean temperature. On average, changes in temperature moved north at 4.5 miles per decade and species shifted an average of 5 miles north per decade. But species-specific movements varied greatly. For example, lobster in the northeastern United States (above) moved north at a pace of 43 miles per decade. Nearly half of all species studied moved south...

"If we follow the temperature, which is easier to predict, that provides a method to predict where the species will be, too," said first author Malin Pinsky, a former Princeton postdoctoral researcher in ecology and evolutionary biology who is now an assistant professor of ecology and evolution at Rutgers University....

The researchers found a "complex mosaic" of climate velocity and species movement in nine areas central to North American fishing industries (above from left to right): the Aleutian Islands (light blue); the eastern Bering Sea (blue); the Gulf of Alaska (light green); the West Coast (purple); the Gulf Coast (orange); the Northeast (peach); Nova Scotia (pink); the southern Gulf of St. Lawrence (red); and Newfoundland (green). The insets (image A) show shifts in the maximum (blue), average (black) and minimum (red) latitude during the period studied for Pacific cod in the Gulf of Alaska, big skate on the West Coast and American lobster in the Northeast. The close-ups of the Eastern Bering Sea (B), the Gulf Coast (C) and Newfoundland (D) show the nuances of regional animal movements that global-scale models often miss. (Image by Science/AAAS)