Sea Life colonizes islands of plastic waste in ocean, scientists say


There is enough plastic waste in the ocean to support the evolution of entire species and potentially harm others, according to a new study.

Published Thursday in the peer-reviewed journal Nature Communication, the report documents the emergence of “neopelagic” communities, those that evolved to live off plastic waste in the ocean.

The study, conducted by researchers at the Smithsonian Environmental Research Center, Williams College and a number of other ocean research institutes, builds on existing knowledge about how ocean species move along ribs on floating debris, such as plastic, seeds and algae. This process is known as ‘rafting at sea’ and it is well studied, but it has long been considered an ephemeral process, and previous research has focused on the transient movement of coastal fauna via rafts rather than on their residence supported on them.

According to the document, the exponential increase in plastic pollution in the ocean has created permanent opportunities for coastal species to exist on the high seas by colonizing floating debris.

In partnership with the non-profit Ocean Voyages Institute, researcher Linsey Haram, who was the first author of the study as a postdoctoral researcher at the Smithsonian Environmental Research Center, analyzed 103 tonnes of plastic from the subtropical gyre. North Pacific, a region of the Pacific. the ocean between California and Japan, and found a number of coastal species, such as anemones and shrimp-like amphipods that thrived on the debris.

“The problems with plastic go beyond ingestion and entanglement,” Haram said in an Press release. “This creates opportunities for the biogeography of coastal species to extend considerably beyond what we previously thought possible.”

Researchers first observed this phenomenon after the earthquake and tsunami that hit Japan in 2011, in which a large swath of debris was swept into the North Pacific Ocean near Hawaii and the west coast of North America. “Hundreds of Japanese coastal marine species” were found alive on debris that had traveled 6,000 kilometers – and many of these species were found to have grown and reproduced for years at sea, “the study said.

Although the data analyzed for their article varied only until 2017, Haram told Motherboard that she continued to monitor the litter that arrived on North American shores in the years that followed. She continued to see plastic traveling across the Pacific until 2021, but the wood stopped arriving a few years after the tsunami.

“This has led us to believe that the exceptional durability and buoyancy of floating plastic debris can provide a unique and sustainable habitat structure on the high seas where coastal species are able to survive,” Haram said in an email. .

This discovery paved the way for questions about how these communities evolved to survive specific ocean surface conditions atop the plastic debris. Haram and his co-authors coined the term “neopelagic” – “neo” meaning “new” and “pelagic” referring to the open ocean – to refer to these species, encompassing both the rafting species and the neuston, a category of oceanic species that live on the surface of the water and have developed unique mechanisms to survive at the “air-sea interface”, such as air sacs that catch the wind.

Floating plastic could also provide a vector for the movement of invasive species, according to the study; So while plastic waste has led to the proliferation of some species, it could turn out to be the downfall of others, who will compete for resources in coastal regions where neopelagic ecosystems land after traveling from the ocean.

“Coastal species are in direct competition with these ocean rafters,” Haram said in the statement. “They compete for space. They compete for resources. And these interactions are very poorly understood.”

The researchers hope their paper will lay the groundwork for future research into this and other biological consequence of the global plastic problem.

“The global plastic pollution crisis is reconfiguring algae and animal communities on the high seas,” Haram told Motherboard. “The downstream effects of this reconfiguration on ocean ecosystems are unknown. ”

Update: This article has been updated with comments from study co-author Linsey Haram.


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