A recent study has revealed a significant decrease in the size of Pacific grey whales since 2000, highlighting the profound impact of climate change and human activities on marine life. Researchers from the University of St Andrews in Scotland and Oregon State University in the United States focused on approximately 200 whales from the Eastern North Pacific population, which consists of around 14,500 individuals.
By analyzing drone images captured between 2016 and 2022 of 130 whales with known or estimated ages, scientists discovered a striking trend: a grey whale born in 2020 is likely to reach a full-grown length of approximately 1.65 meters less than one born in 2000. This represents a considerable 13% decrease in the total length of mature grey whales, which typically measure between 11 and 12 meters.
The researchers emphasized the potential implications of this reduction in size on the whales’ survival rates and reproductive success. “Their diminished size could have significant impacts,” noted the study published in the journal Global Change Biology.
The study also found a correlation between the whales’ shrinking size and changes in the ocean’s “upwelling” and “relaxation” cycles—a process crucial for bringing nutrient-rich waters to the surface and supporting marine ecosystems.
This phenomenon is part of a broader pattern affecting marine mammals globally. The findings serve as a stark reminder of the interconnectedness of climate systems and the far-reaching consequences of environmental changes. For regions across the Pacific, including Asia’s coastal nations, these changes could impact biodiversity, fisheries, and the livelihoods of communities dependent on marine resources.
Reference(s):
Pacific coast grey whales shrinking in size as climate changes
cgtn.com
