On Wednesday, researchers published their findings in PLOS ONE of ecological fallout connected to an ocean heat wave experienced in the North Pacific between 2014-2016. Specifically, researchers looked at the mass die offs of the common murres sea birds. The authors of the study estimate that common murres suffered up to 1 million deaths during that two-year span. The report is a stark precedent of things to come as our planet’s temperatures rise.
Inside Climate News reports that the authors called the event “unprecedented and astounding.” Part of what makes news of the common murres demise so tragically “astounding” is that they are considered one of the more hearty and adaptable animals. Researchers looked to figure out why such high numbers of dead or emaciated common murres were being reported all over the northern Pacific coast, searching for parasites or any other reason that the very successful predatory common murres were starving and dying.
Eliminating other variables, the team was left with one—what scientists call “the blob.” This is the name for the expanding warm temperature phenomenon that was recorded through the north Pacific between 2014-2016.
Biologist John Piatt was one of the people searching for an answer, and found that when you looked at the bottom of the oceanic food chain, and while some argued initially that fish stock in the Pacific hadn’t fallen enough to hurt the murres, Piatt researched further and discovered that the heatwave seemed to have changed the very bottom of the chain: phytoplankton and zooplankton.
"The older, fatter, nutritionally richer zooplankton were replaced by southerly or offshore species that weren't as big and nutritionally rich,” he tells Inside Climate News. But it’s not only this drop in overall nutrition. Scientists have studied and found that rising temperatures lead to fish such as cod and flounder to raise their metabolism as much as 200%. This means these fish need a lot more food, and those fish eat the same food that the common murre does. So a combination of lowered nutritional value and rising competition has led to these mass die offs.
Inside Climate News reports that climate scientist Thomas Frölicher believes climate change is the big contributor to the record-breaking 2014-2016 Pacific Ocean heatwave, and that means things will be getting a lot worse before they get better. Frölicher tells Climate News that unabated, by 2100, ‘"If we follow a high-greenhouse-gas-emissions scenario, these heat waves will become 50 times more frequent than preindustrial times." That magnification would only be reduced to 20 times more heat waves if the planet’s inhabitants followed the Paris climate agreement.
In September, the National Oceanic and atmospheric Administration (NOAA) reported that scientists were monitoring a “new marine heatwave off the West Coast,” that resembled the 2014-2016 heat wave phenomenon that led to the death of the common murres.