Why Are Dead, Emaciated Gray Whales Washing Up On Pacific Shores?

Merrill Gosho, NOAA/Public Domain

Scientists are scrambling to uncover why North Pacific gray whales are emaciated and washing ashore along the coast.

Tourists from across the globe head to Monterey, California, each year to watch whales of all kinds in their natural habitats. But this year, according to The New York Times, not all whales on the West Coast are faring so well.

At least 167 dead North Pacific gray whales have washed ashore from Mexico to Alaska, the publication reported last week, and that is probably just the tip of the iceberg — most dead whales will sink to the ocean floor.

This particular “whale fall,” as scientists term such a happening, has risen to the degree of what is called an “unusual mortality event”.

Scientists have noted that many of the whales washing ashore appear emaciated, and those returning to their birthing grounds in the lagoons of Baja California in Mexico this year were emaciated as well.

Researchers have not yet determined the cause of this massive die-off but are working through myriad data to find out what might be going on. The Times cited “sea ice extent, ocean temperature, food availability, entanglement in fishing gear, marine pollution, toxic algae blooms, collisions with large ships and predation by killer whales” as avenues scientists are currently exploring.

It is possible that the population of about 27,000 gray whales simply exceeded the ocean’s ability to support them, and it is also known that warmer water temps, less oxygen in the oceans and the acidification of the water due to climate change negatively impacts all manner of marine life.

“A study using multiple climate and ecosystem models, published this month, projected that for every 1.8 degree increase in ocean temperature, there is an associated 5 percent drop in the total mass of sea animals,” the Times noted.

Read the full report here.