“Shrinking Gray Whales: A Warning Sign for the Pacific Northwest Coast Ecosystem”

The study conducted by Oregon State University researchers has revealed a concerning trend among gray whales in the Pacific Northwest. The study focused on the Pacific Coast Feeding Group (PCFG), a subset of about 200 gray whales that spend their summers feeding in the shallow waters off the Oregon coast. These whales have been found to be significantly smaller in size compared to their counterparts in the larger Eastern North Pacific (ENP) population.

Researchers from OSU’s Marine Mammal Institute’s Geospatial Ecology of Marine Megafauna (GEMM) Lab have been monitoring the PCFG gray whales since 2016, using drones to measure their size. The data collected from 2016 to 2022 revealed that the whales born after 2000 are expected to reach adult body lengths that are 1.65 meters shorter than those born prior to 2000. This represents a loss of more than 13% of their total length, which is a significant decline.

Enrico Pirotta, the lead author of the study, emphasized the importance of body size for animals, affecting their behavior, physiology, and overall health. Smaller whale calves may struggle with independence, impacting their survival rates. For adult gray whales, reproductive success is a major concern, as smaller size may affect their ability to allocate energy towards reproduction and maintaining their health.

The study also highlighted the impact of changes in the ocean environment on the food availability for these gray whales. The balance between upwelling and relaxation in the ocean plays a crucial role in providing nutrients for the growth of plankton and other prey for the whales. Changes in these patterns, possibly influenced by climate change, could be contributing to the decline in whale size.

Researchers are now focused on understanding the downstream consequences of the declining body size of PCFG gray whales and identifying the environmental factors driving these changes. The long-term monitoring of this subgroup provides valuable data for detecting changes in body condition and investigating the underlying causes.

The findings of this study raise concerns about the health and reproductive success of the affected gray whales and highlight the importance of monitoring and protecting these iconic marine mammals. Further research is needed to address the underlying factors contributing to the decline in body size and to develop conservation strategies to ensure the long-term survival of these whales.