Marine heat wave kills nearly 1 million birds

1 million seabirds killed in the Pacific Ocean... Nearly 4 years after these mysterious deaths, a scientific study provides some details about the culprit.

This recent scientific study’s sad result resolves a mystery that dates back several years

Between summer 2015 and spring 2016, 62,000 common murres, who had starved to death were found beached. But that was just a tiny fraction of the total number of victims. Nearly 4 years after these events, scientists have estimated nearly 1 million birds have died and are providing some details about the causes.

The culprit was a marine heat wave that began in 2013 in the northeastern Pacific Ocean and intensified during the summer of 2015. As a result, a 1,600 km2 area warmed up by 3°C, disturbing ecosystems.

Some algae species that are essential to the food chain, grew rarer, while harmful algae ran rampant. Some predators, such as salmon, halibut, and cod, experienced metabolic changes causing them to eat more, putting them in competition with fish-eating birds. Finally, phytoplankton production also declined greatly, leading to deaths among other species.

This heatwave was not an isolated event. In New Zealand, a heatwave spanning 1 million km2, visible from space, was discovered in late 2019. Due to global warming, these phenomena could become more common.