During recent marine heat waves, millions of gelatinous, pickle-like filter feeders washed up on West Coast beaches.

Little has been understood about how the population explosion of the seemingly alien creatures, called pyrosomes, affected life in the Pacific Ocean.

But a new study shows the proliferation of the animals might have sucked up precious energy from the food web, likely affecting fish and animals higher up in the food chain.

The study by Oregon State University researchers working with the National Oceanic and Atmospheric Administration analyzed how a model of the ocean food web changed before and after recent marine heat waves.

The study found that the heat wave had wide-ranging effects on the movement of nutrients and energy in the Pacific Ocean, with pyrosomes absorbing much of the energy. The results are significant since the models suggest that most of the redirected energy to pyrosomes did not go on to feed other species.

In the last decade, the Northern California Current marine ecosystem, which extends from Vancouver Island in Canada to Cape Mendocino in California, has experienced a period of abnormally warm temperatures.

In 2014, a particularly intense marine heat wave brought temperatures roughly 5 degrees Fahrenheit above normal and was dubbed "The Blob," for its appearance on satellite temperature maps. According to NOAA, that heat wave continued until mid-2016, and abnormally warm temperatures have occurred in the North Pacific nearly every year since 2019.

Since then, regional research and studies have documented a decline in salmon runs, die-offs of sea birds and harmful algal blooms that closed Dungeness crab fisheries, all related to marine warming. The study from Oregon State University is one of the first to comprehensively analyze the heat wave's effects across the entire food web from the smallest phytoplankton and detritus on the seafloor to whales, fish and seabirds, said co-author Dylan Gomes.

"What this showed us is that these heat waves impact every predator and prey in the ecosystem through direct and indirect pathways," he said.

Researchers compared two "end to end" ecosystem models, one populated with data from 1999 to 2012 and one from after the onset of the marine heat wave in 2014 until 2022. Researchers estimated the biomass for 86 different organism groups with data from NOAA sampling and commercial and recreational fisheries, satellite information on phytoplankton and other studies.

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