Humpback whales face threats from warming seas in the Pacific

Humpback whales, including the notable matriarch Big Mama, have begun to return to the Salish Sea after a long absence, signaling a positive trend in their conservation. However, this resurgence is threatened by climate change, which is altering ocean temperatures and affecting the whales' breeding and feeding patterns. Ideal sea temperatures for calf births range from 21C to 28C, but rising global temperatures may push many breeding grounds beyond this range by the end of the century. A 2022 study from the University of Hawaii and the Pacific Whale Foundation predicts that under a moderate climate scenario, approximately 37% of humpback breeding areas could exceed the upper temperature limit. The study highlights the significant impact of greenhouse gas emissions on the viability of these habitats, emphasizing the need for protective measures to accommodate the whales' shifting breeding grounds. In addition to temperature changes, climate change is also affecting the timing of the spring thermal transition day, which influences the migration patterns and habitat use of humpbacks. This shift may disrupt the availability of prey, further complicating the whales' survival. Large mammals like humpbacks are less likely to adapt quickly to these changes compared to smaller marine species. Moreover, increased human activity, such as whale watching, poses additional risks through noise pollution and potential collisions with boats. As scientists continue to monitor these changes, the urgency to protect humpback whales and their habitats becomes increasingly critical.