Crisis in the Pacific: North Pacific Humpback Whales Face Alarming Decline Due to Marine Heat Waves”
In less than a decade, the North Pacific humpback whale population has witnessed a staggering 20% decline, signaling a potentially troubling future for these majestic sea creatures. A study released on Wednesday points to marine heat waves as the primary culprit behind this alarming trend.
READ: Navigating Amsterdam’s Waterways: A Canal Cruise Experience
North Pacific
Conservation efforts and the cessation of commercial whaling in 1976 had contributed to a steady increase in the humpback population until 2012. However, over the past decade, researchers reported a sharp decline in whale numbers, challenging the assumption that the population would plateau at its natural “carrying capacity.”
The study, published in the journal Royal Society Open Science, involved a team of 75 scientists compiling the largest photo-identification dataset ever created for a large marine mammal. Tracking North Pacific humpback populations from 2002 to 2021 using images of their unique tails, the team logged over 200,000 sightings of more than 33,000 individuals.
Contrary to expectations, the humpback population experienced a significant decline from 2012 to 2021, falling 20% from around 33,000 individuals to just over 26,600. For a subset of whales wintering in Hawaii, the drop was even more pronounced, reaching 34%.
The study linked this decline to a marine heat wave between 2014 and 2016, the strongest and longest ever recorded in the Pacific Northeast. This heat wave caused temperature anomalies of 3 to 6 degrees Celsius (5 to 11 degrees Fahrenheit), disrupting the marine ecosystem and affecting the availability of humpback prey. The researchers estimated that approximately 7,000 whales likely starved to death during this period.
The abrupt decline in a long-lived species like the humpback suggests a major disruption in the oceans. The extreme marine heat is believed to have reduced the carrying capacity threshold for humpbacks, impacting not only their food source but also other marine species. The decline in tufted puffins, sea lions, seals, and disruptions in commercial fisheries further highlight the broader implications for ocean health.
The study emphasizes the need for climate action alongside conservation efforts. While the rebound of humpback whales from the brink of extinction is a success story, the changing oceans present new challenges that require urgent attention and adaptation to ensure the continued well-being of these magnificent creatures in the face of environmental threats.
