Analysis showed the presence of plastic fibers and electrical insulating and flame retardant materials
A survey of sediments, fish and invertebrates that live in depths, between 400 and 1,500 meters below the surface, points to the presence of microplastics and so-called POPs (persistent organic pollutants). The collections were carried out in , approximately 140 kilometers from the coast.
The study was published in the Marine Pollution Bulletin by researchers from IO-USP (Oceanographic Institute of the University of São Paulo) and Ipen (Institute for Energy and Nuclear Research).
“This is another step towards understanding the occurrence of these pollutants in the deep sea of Brazil. The biggest challenge, however, is determining the origin of the compounds, since both microplastics and POPs are transported in the atmosphere, and how they impact deep-sea fauna”says Gabriel Stefanelli-Silva, first author of the study, carried out during his doctorate at IO-USP with a scholarship from .
The work was supervised by Paulo Sumida, coordinator of LAMP (Deep Sea Ecology and Evolution Laboratory) at IO-USP.
The study is also part of the project “Diversity and evolution of deep ocean fish (DEEP-OCEAN)”supported by FAPESP within the scope of the Biota Program and coordinated by Marcelo Roberto Souto de Melo, professor at IO-USP who also signed the work.
In the study, two categories of POPs were analyzed in sediments and fish: PCBs (polychlorinated biphenyls), which are electrical insulators, and PBDEs (polybrominated diphenyl ethers), which act as flame retardants.
In sediments, the only POPs detected were PCBs. In fish, two classes of persistent pollutants were found. Among the species studied were Parasudis truculenta, Hoplostethus occidentalis, Coelorinchus marinii and Neoscopelus macrolepidotus.
The samples were obtained during two cruises on the oceanographic ship Alpha Crucis, from USP, which carried out a series of collections for different studies in September and November 2019.
Microplastics
While the analysis of sediments and fish looked for POPs, in invertebrates the objective was to evaluate the presence of microplastics, which are fragments of plastic less than 5 millimeters in length.
“Even when the origin of plastic pollution is the coast, at some point these particles reach the deep sea, as the entire marine environment from 200 meters deep is called. Detritivorous organisms [que se alimentam de detritos no leito marinho] and filters are especially prone to ingesting microplastics.”explains Stefanelli-Silva.
It is no coincidence that among the 9 invertebrate species analyzed, the one that contained the most microplastics in the digestive system was the sea cucumber Deima validum.
Of all the types of fibers found, 5 were classified as microplastics. Among the polymers detected are polyamide and polyacrylonitrile, used in the textile industry. As for polyaryletherketone and polystyrene, which are resistant plastics with diverse applications, and polysulfide, a synthetic rubber, the possibility is raised that the source of contamination comes from the offshore industry in the Santos Basin. Currently, 5 platforms operate in the area and 6 others are planned for 2027.
To avoid contamination of the samples by microplastics present in the research environment, the researchers followed a protocol that included the use of clothing and analysis instruments without synthetic fibers. In addition, strict control of microplastics was carried out on the surfaces used and even in the air in the environment.
The researchers emphasize that this was a first survey, which should be deepened in future studies. In previous work, Stefanelli-Silva, Sumida and other researchers analyzed animals collected in Antarctica between 1984 and 2016, deposited in the Prof. Biological Collection. Edmundo F. Nonato, from IO-USP.
Among the finds, the oldest record of the presence of microplastics in Antarctica was found, a fiber measuring just over 2 millimeters detected in the viscera of a small crustacean, similar to a shrimp and collected in 1986.
“The deep sea is difficult to access, has a very high cost for research, but is very important to monitor. The presence of microplastics and persistent pollutants shows part of the impact of human activities and how this environment is not as far from people as one might think”concludes Sumida.
O artigo Microplastics and POPs on the Southwestern Atlantic deep-sea floor: a study of megafauna and sediments pode ser lido .
This text was originally published by , on May 20, 2026. The content is free for republication, the source is cited, and was adapted to the Poder360 standard
