Biofouling (biofouling or biological fouling) is a natural and widely studied phenomenon that consists of the accumulation of living organisms (from bacteria to plants, algae and animals, the best known cases being limpets and mussels) on an artificial submerged surface or in contact with water (buoys, boat hulls, jetties...). For a few years now, this process has been taking place, and they have also observed and studied it in the garbage that floats or remains submerged in seas and oceans. This new biofouling manifests itself, for example, in the pieces of plastic that are covered by living organisms, and that move like an improvised boat beyond their natural habitats.
A study led by experts from the Smithsonian Environmental Research Center and the University of Hawaii at Manoa (both institutions in the United States), has now analyzed the biofouling generated by plastic waste in the waters of the large known waste accumulation area. as the North Pacific Subtropical Gyre and has reached a very interesting conclusion: floating plastic debris is facilitating the spread and reproduction in the high seas of species that until now were only present in coastal waters.
This observation may seem anecdotal -microorganisms, plants and animals migrating on board pieces of plastic- but it is scientifically relevant because it can mean important alterations in various ecosystems and species, warns this study whose first author is Linsey E. Haram. Thus, after reaching the high seas, these species that navigate on plastics -from the California coast, for example- can also reach remote islands such as those of Hawaii, indicate the authors of this study to show the seriousness of the situation. The results of this work have been published in the journal Nature Ecology and Evolution (April 17, 2023).
"Our results suggest that coastal organisms can now reproduce, grow and persist in the open ocean, creating a new community that did not exist previously, sustained by the vast and growing sea of plastic debris," said Gregory Ruiz, co-author of the study. "We are facing a paradigm shift - a totally new situation - in what we consider to be barriers to the distribution and dispersal of coastal invertebrates."
Previous studies have shown that various organisms, including some coastal species, colonize marine plastic debris, but until now they did not know that established coastal communities could persist in the open ocean.
"These findings identify a new human-caused impact on the ocean, documenting the scale and possible consequences that were not previously understood," the authors of the new study warn.
The presence of coastal species that persist in the North Pacific Subtropical Gyre and then approach Hawaii is a change from the situation known so far, indicating that the islands are at greater risk of colonization by invasive species, the authors of the research detail. .
Those responsible for the study analyzed 105 plastic samples collected by The Ocean Cleanup during its 2018 and 2019 expeditions in the North Pacific Subtropical Gyre.
"We were very surprised to find 37 different species of invertebrates that normally live in coastal waters, more than triple the number of species we found living in open water, not only surviving on the plastic, but also reproducing," Linsey explained. Haram. "We were also impressed with the ease with which inshore species colonized new buoyancy, including our own instruments, an observation we are investigating further."
