Over the past year, weakened, malnourished, and sometimes dead seabirds have turned up along the Pacific coast from California to Alaska at an alarming rate.
Now, thousands of these birds have been discovered dead on the shores of an Alaskan lake. The finding was unusual in both the scale of the die-off and their location — given that they typically stick to the ocean.
The Associated Press reported this week that between 6,000 to 8,000 common murres were found on the shore of Lake Iliamna.
John Piatt, a research wildlife biologist for the US Geological Survey, told the AP that although murres occasionally land in fresh water, thousands of birds “is pretty mind-blowing.”
This winter, thousands of dead common murres washed ashore a beach along western Prince William Sound near the town of Whittier, Alaska. Testing of the birds found that most were dying of starvation. Biologists have hypothesized that the birds may be starving because warmer ocean waters — due to climate change and El Niño — are causing fish to swim deeper in search of cooler water, too deep for the murres to reach.
However, researchers have noted that there are many unknowns. Murres’ winter diets are less studied than their summer diets and fish surveys in Alaska are not routinely done.
It is not completely unusual for common murres to die in large numbers, but this die-off, with 36,000 confirmed dead so far, is “far higher” than previous die-offs, wildlife biologist Sarah Schoen told the AP. In addition, typically only a fraction of dead birds wash ashore and not all of the many beaches in Alaska have been surveyed, so the total number of deaths could be in the hundreds of thousands.
So far, it is unclear what the finding of dead murres at Lake Iliama means, including whether and how it that die-off is related to the die-off that has been happening along the Pacific coast all winter. Perhaps the murres went searching for food or perhaps they ended up at the lake for another reason.