A new study has connected changes in the movement of North Atlantic right whales to decreased food availability and rising temperatures in the Gulf of Maine's deep waters. In recent years, right whales have been showing up in unexpected places, putting the endangered species at increased risk. Researchers published the study in Oceanography and scientists from more than ten institutions conducted the research and provided insights to this vital issue complicating conservation efforts.
The lead author on the paper and a senior research scientist at Bigelow Laboratory for Ocean Sciences, Nick Record, said that the climate-driven changes rippling throughout the Gulf of Maine have severe consequences for the small number of remaining right whales. Record said further that climate change is outdating many of our conservation and management efforts, and it's challenging to keep up with the rapid evolution of this ecosystem.
In the North Atlantic Ocean, climate change has shifted circulation patterns such as the currents that flow into the Gulf of Maine's depths. This research discovered 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 whales' primary prey, a high-fat, rice-sized crustacean called Calanus finmarchicus.
A research scientist at the New England Aquarium and an author on the paper, Dan Pendleton, said that ocean conditions determine where right whales go and when they go there. Pendleton noted that for decades, they have known and when to find the right whales. Now that paradigm is breaking down, and they are seeing changes to behaviors that had remained consistent since before people starting observing them.
In preparation for winter, right whales have historically made an autumn journey to the mouth of the Bay of Fundy to feat. In the absence of abundant Calanus in that region, right whales are following their food, which means foraging well outside of the area established to protect them.
They are much more vulnerable to fatal encounters with ships and fishing gears due to the misalignment between conservation measures and the whales' current behavior. The researchers, however, believe that the secure connection between water temperature, Calanus, and right whales makes it possible to predict where new right whales habitats develop and to span accordingly.
Accurate prediction requires useful data, however, and routing measurements to monitor change in Calanus abundance in the Gulf of Maine have been drastically reduced due to a lack of funding. Researchers are working hard to recover capability in the region, and Record hopes that he may be able to develop models that use alternative data sources to forecast right whale locations, such as monitoring seawater for signs of whale DNA and collecting observations by citizen scientists.
