PORTLAND (Maine), USA: In a fresh study, researchers from the National Oceanic and Atmospheric Administration (NOAA) have shed light on the alarming threats faced by marine mammals dwelling in U.S. waters due to climate change.
The assessment, the first of its kind, reveals the perilous vulnerability of whales, dolphins, and seals to warming ocean temperatures, rising sea levels, decreasing sea ice volumes, and alterations in ocean chemistry.
The study delved into over 100 stocks of American marine mammal species, revealing that more than 70% of these stocks are highly susceptible to significant threats, such as habitat and food loss, induced by the consequences of warming waters. Moreover, the impacts encompass loss of dissolved oxygen and modifications in ocean chemistry.
Among the most susceptible to climate change are large whales, including humpbacks and North Atlantic right whales. Toothed whales and dolphins are also at a heightened risk, according to the findings published last month in the journal PLOS ONE. The study emphasizes the urgent need for a shift in how the U.S. manages these marine creatures in the face of climate change, as advocated by marine mammal conservationists.
Matthew Lettrich, a biologist and lead author of the study, stressed the importance of adapting U.S. marine mammal management strategies in response to climate change. He pointed out that the effects of climate change are already evident, with some marine mammal populations more susceptible to these changes than others. The study demonstrates that a significant proportion of these populations are highly vulnerable.
The focus of the researchers was on marine mammals residing in the western North Atlantic Ocean, Gulf of Mexico, and Caribbean Sea. These animals fall under the stewardship and protection of the National Marine Fisheries Service, a federal government entity responsible for marine resource management.
Assessing the degree of exposure, sensitivity, and adaptability of these animals to climate change, the scientists found that 72% of the stocks were highly or very highly vulnerable to climate change. The primary harm caused by the warming ocean is the disruption of marine mammals’ ability to find food and the reduction of suitable habitat.
However, the scientists also highlighted that changes in ocean temperature and chemistry can alter sound transmission, affecting sonar-like echolocation used by marine mammals for communication and hunting. The study underlines the necessity of considering climate change in the adequate management of these species.
Regina Asmutis-Silvia, a biologist with Massachusetts-based Whale and Dolphin Conservation, emphasized the significance of utilizing the study’s insights to implement protective laws for whales. She stressed that the U.S., with its wealth of marine mammal data, should leverage this information to enforce robust laws for the protection of these creatures.
The study’s global approach is crucial, as climate change’s impact on marine mammals extends beyond specific species or narrow geographic regions. It affects a wide array of marine mammal stocks across the United States, emphasizing the urgency of comprehensive conservation measures.
The study also highlighted potential impacts on the distribution and behavior of marine mammals, including migratory patterns that traverse international boundaries, necessitating enhanced international cooperation.
In recent years, the federal government has implemented various strategies to safeguard declining whale species, such as imposing restrictions on commercial fishing and vessel speed. Yet, the study underscores the need for ocean managers to anticipate a future where warming waters may render current whale habitats less suitable.
Gib Brogan, campaign manager with environmental group Oceana, emphasized the study’s guidance for prioritizing vulnerable species and advocated for explicit consideration of ocean changes in conservation efforts. Preserving biodiversity, including marine mammals, requires a proactive approach to adapt to current and future changes in the ocean.
