Today we will be discussing aquatic species in the North Atlantic Ocean, and how climate change is affecting them. We will focus primarily on the North Atlantic right whale. Warming oceans, rising seas, droughts, ocean acidification are some factors that are affecting the quantity and distribution of aquatic species on the Northeastern U. S. continental shelf. Climate has a distinct effect on oceanic life on the Northeastern U. S. continental shelf ecosystem. Climate change and variability are driven by both natural and human activities. These factors combine with each other to create physical biological, and chemical variability in the ecosystem (Climate Change in the Northeast U. S. Shelf Ecosystem | NOAA Fisheries).
Over the course of the last twenty years, water temperatures off the Northeast coast of the U. S. have warmed at a faster pace than the global ocean. The most extreme example of this is found in the Gulf of Maine, where the water temperatures have warmed faster than 99 percent of the global ocean (See graph below).
Not only are we experiencing human related changes, but we are also seeing natural changes in the earth’s climate that are having an affect on the ecosystem on the Northeast U. S. continental shelf. One example of this is the oscillations in the North Atlantic Ocean that are linked with the North Atlantic Oscillation and the Atlantic Multidecadal Oscillation. The position and strength of the Gulf Stream are also tied to the oceanography and climate of the ecosystem on the Northeast continental shelf. When the Gulf Stream is located further North, it leads to warmer waters in the North Atlantic. Oceanography on the Northeast shelf can be impacted in a similar way by the Atlantic Meridional Overturning Circulation (Climate Change in the Northeast U. S. Shelf Ecosystem | NOAA Fisheries).
As we mentioned in the last section, the location of the Gulf Stream can impact the ecosystem of the North Atlantic. One species that is being negatively impacted by the Gulf Stream is the North Atlantic right whale. Shifts in the Gulf Stream are causing this species to go extinct by causing damage to the food chain, forcing the whales to relocate to waters that are more dangerous (According to a study by Oceanography). Professor Erin Meyer-Gutbrod from the University of South Carolina, along with her team of researchers found that a warming global climate has weakened the Gulf Stream. This has moved warmer water to the north and west into the Gulf of Maine and off Nova Scotia’s southern coast, the location where the right whale normally resides (Hess)
The right whale’s primary food source is the Calanus finmarchicus, a copepod species. Right whales tend to feed on this species most in its later stages of development. Because it is a primary food source, the number of Calanus finmarchicus is affected by the number of newborn right whale calves that are present. As a result of the warmer waters caused by the shifted Gulf Stream, there was a lower number of copepod in the waters off of Maine and Nova Scotia after the year 2010. For this reason, there was a noticeable decrease in the number of newborn right whale calves. Researchers have identified 187 North Atlantic right whales in Canada’s Gulf of St. Lawrence during the summer. This number is about 40 percent of the population. The photographs of North Atlantic right whales were collected during surveys conducted between 2015 and 2019 (NOAA Fisheries).
Because of the increase in water temperatures, fewer numbers of right whales were spotted in the typical areas. Instead, the whales moved to the north and west into the Gulf of St. Lawrence to the north of Nova Scotia. This created a problem because there was no management plan for them at the time. This lead to a spike in the number of right whale carcasses retrieved, with a total of 17 in 2017 and 10 in 2019. The death of many of the whales was attributed to being hit by ships or being tangled in fishing gear (Hess).
Climate Chane in the Northeast U.S. Ecosystem | NOAA Fisheries. May 24. 2021. Web. Feb. 5, 2021.
Hess, Lily. Climate Change driving North Atlantic right whales to extinction, study says. Landscape News. www.globallandscapesforum.org. Sept. 11, 2021. Web. Feb. 16, 2022.
NOAA Fisheries. Forty Percent of North Atlantic Right Whale Population Using Gulf of Saint Lawrence as Seasonal Habitat. December 2, 2021. Web. March 29, 2022.
NOAA Fisheries. Forty Percent of North Atlantic Right Whale Population Using Gulf of Saint Lawrence as Seasonal Habitat. Image. December 2, 2021. Web. March 29, 2022.