Washington: The researchers found a connection between recent changes in the movement of North Atlantic right whales to decreased food availability and rising temperatures in the Gulf of Maine's deep waters.
Right whales have been showing up in unexpected places in recent years, putting the endangered species at increased risk. The study, which was published in Oceanography and conducted by scientists from more than 10 institutions, provides insights to this key issue complicating conservation efforts.
According to the recent study, the climate-driven changes rippling throughout the Gulf of Maine have serious consequences for the small number of remaining right whales. Climate change is outdating many of our conservation and management efforts, and it's difficult to keep up with the rapid evolution of this ecosystem.
"The climate-driven changes rippling throughout the Gulf of Maine have serious consequences for the small number of remaining right whales. Climate change is outdating many of our conservation and management efforts, and it's difficult to keep up with the rapid evolution of this ecosystem," said Nick Record, a senior researcher of the study.
Climate change has shifted circulation patterns in the North Atlantic Ocean, including the currents that flow into the Gulf of Maine's depths. This study found that some of these deep waters have warmed nearly 9 degrees Fahrenheit since 2004 - twice as much as the fastest warming waters at the surface.
These changes have drastically reduced the supply of right whale's primary prey - a high-fat, rice-sized crustacean called Calanus finmarchicus. Right whales have historically made an autumn journey to the mouth of the Bay of Fundy to feast in preparation for winter. In the absence of abundant Calanus in that region, right whales are following their food – which means foraging well outside of the areas established to protect them.
The misalignment between conservation measures and the whales' current behaviour makes them much more vulnerable to lethal encounters with ships and fishing gear.
However, the researchers believe that the strong connection between water temperature, Calanus, and right whales makes it possible to predict where new right whale habitats develop, and to plan accordingly.
As part of previous research in 2012, Record and Pendleton used data about Calanus and oceanographic conditions to develop an algorithm to identify right whale habitats. Working with collaborators, including Andrew Pershing from the Gulf of Maine Research Institute, they determined that the region south of Nantucket might be a previously unknown right whale habitat.
Recent surveys have revealed the area is indeed a hotspot for the species and the researchers now hope to develop similar tools to help people predict and prepare for the future movement of right whales.
