Millions of strange blob-like creatures have washed up on West Coast beaches in recent years due to warming waters caused by climate change.
Gelatinous, transparent mas have been found along the coasts of northern California and Oregon, and occasionally as far as Alaska, but generally live in warm seas and at great depths.
Now, scientists at Oregon State University have discovered that these pyrosomes or “marine pickles” are appearing en masse due to a major marine heatwave that began in 2013 – marking the first time that these animals have been observed for 25 years.
Since the proliferation of pyrosomes in the Pacific Ocean, they also consume the majority of the sea’s energy, leading to a decline in the number of salmon and seabirds.
Pyrosomes are a gelatinous blob-like creature that resembles a pink tube with rigid bumps covering its body.
Pyrosomes wash up on the coasts of Oregon and northern California
Pyrosomes feed on phytoplankton, which form the basis of marine food webs that provide food for a wide range of marine creatures, but the growing number of marine pickles means there isn’t enough to go around .
These creatures can range from a few inches to 60 feet long and resemble a pink tube with rigid bumps covering its body.
Pyrosomes are colonies of thousands of animals called zooids that form in a hollow tube that can grow large enough for a human to fit through.
Marine animals have a gene called luciferase that produces light and when it reacts with a luminescent chemical, it sends light up and down the tube, allowing it to see several meters in front of it.
They can also reproduce through asexual reproduction – effectively cloning themselves – or with a sexual partner.
A new study has found that pyrosomes, also known as marine pickles, consume the majority of energy in the ocean off the west coast of the United States.
Pyrosomes are not an adequate food source for other species, as 98% of their waste ends up on the sea floor.
The researchers looked at data from 80 groups of creatures, three nutrient pools, five detritus pools and two fisheries collected since 2014.
“The pyrosomes consume the animals at the base of the food web and trap that energy,” said Lisa Crozier, a research scientist at the NOAA Fisheries Northwest Fisheries Science Center and co-author of the paper.
“They take energy out of the system that predators need,” she added.
Pyrosomes can be up to 60 feet long and before 2014 had not been seen for 25 years
Pyrosomes are not eaten as frequently as other creatures, like jellyfish, and the study suggests that this “may be because they are more difficult to digest, offer lower energy content, or remain new in the food web, so predators have not yet reacted.”
According to the study, pyrosomes have long been considered “trophic dead ends” because they cannot serve as an energy source for other species and their nutritional value for other creatures that have consumed them in recent years remains unclear. .
“This impacts the entire ecosystem… the pyrosome consumes energy that would normally have passed through multiple prey to ultimately end up in a salmon,” said Dylan Gomes, co-author of the study. Seattle weather.
Pyrosomes are not eaten as frequently as other creatures, like jellyfish, and the study suggests that this “may be because they are more difficult to digest, offer lower energy content, or remain new in the food web, so predators have not yet reacted.”
The 2013 marine heatwave, nicknamed “the Blob”, increased water temperatures, allowing pyrosomes to thrive while some fisheries closed due to declines in salmon, cod and Dungeness crab .
Scientists wonder whether rising temperatures are to blame because animals’ metabolic rates increase in warmer water and force them to use more energy.
“You can think of it this way: There is more consumption for the same amount of seafood produced,” Gomes said. NewScientist.
Gomes said the study does not incorporate factors that could affect the decline of marine life, such as falling oxygen levels caused by warming waters.
However, he added: “This is a first attempt to try to understand how marine heatwaves are changing ecosystems in the northeast Pacific.”
The team also compared other sea creatures to pyrosomes and found that they benefited the most from the ecosystem, while other species like jellyfish, cod, sardines, sea snails and other creatures did not emerge, leading to a decrease in their population.
While other creatures like salmon pass on their energy source to feed larger animals, the study suggests this is not the case for pyrosomes, where 98% of their waste and remains accumulate in the seafloor – called detritus ponds.