A new report suggests a warm “blob” of water could be behind the mass starvation of a North Pacific seabird.
According to a report published in the science journal PLOS ONE, about 62,000 dead or dying common murres washed ashore between California and Alaska between summer 2015 and spring 2016. Carcass recovery brings the death estimate up to around one million in total.
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| On Jan. 1 and 2, 2016, 6,540 common murre carcasses were found washed ashore near Whitter, Alaska, translating into about 8,000 bodies per mile of shoreline – one of the highest beaching rates recorded during the mass mortality event. (Photo by David B. Irons) |
The report says there’s nothing to suggest the emaciated birds died from anything other than starvation.
Additionally, no murre chicks were born at breeding colonies between 2015 and 2017.
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Researchers linked the deaths to a “large mass of unusually warm seawater” known as the “Blob” and the strong El Niño that followed, creating a “severe marine heatwave” stretching from California to Alaska between 2014 and 2016.
In a statement, authors said the mass deaths “raise a red-flag warning about the state of marine ecosystems on the continental shelf of western North America.”
The study links to previous research suggesting that warmer marine temperatures reduce both the quantity and quality of phytoplankton – reducing the health and numbers of fish who eat them and increasing the metabolic needs of larger fish that compete with murres for food.
Researchers hypothesize that the warm water ultimately led to the birds’ mass starvation and lack of reproduction.
The murre die-off revealed a major disruption in marine food webs, with alarming declines not only in murres, but in other seabirds, commercial fish and great whales between 2016 and 2019.
Researchers say they are only beginning to understand “the mechanisms and full magnitude of effects of the 2014-16 heatwave, and what it portends if such heatwaves become stronger and more frequent, as predicted.”
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