Whales and sea turtles hit especially hard
FRISCO — Not long after researchers managed to quantify the unbelievable amounts of plastic waste going into the world’s oceans, another team of scientists at Plymouth University said they’ve traced how many species are affected by the debris.
In all, nearly 700 species of marine animals have been recorded as having encountered man-made debris such as plastic and glass, the scientists said after looking at records of 44,000 animals and organisms that became entangled in, or swallowed debris.
Plastic accounted for nearly 92 per cent of cases, and 17 per cent of all species involved were found to be threatened or near threatened on the IUCN Red List, including the Hawaiian monk seal, the loggerhead turtle and sooty shearwater.
These incidents had occurred around the world, but were most commonly reported off the east and west coasts of North America, as well as Australia and Europe.
“The impact of debris on marine life is of particular concern, and effects can be wide reaching, with the consequence of ingestion and entanglement considered to be harmful,” said researcher Sarah Gall, coauthor of the study published in the Marine Pollution Bulletin. “Reports in the literature began in the 1960s with fatalities being well documented for birds, turtles, fish and marine mammals.”
Plastic rope and netting were responsible for the majority of entanglements, with a high number of incidents affecting northern right whales, green, loggerhead and hawksbill turtles, and the northern fulmar.
Plastic fragments were the highest recorded substance for ingestion, with the green sea turtle and northern fulmar again, the Laysan albatross, the Californian seal lion, the Atlantic puffin, and the greater shearwater among the worst affected species.
“We found that all known species of sea turtle, and more than half of all species of marine mammal and seabird had been affected by marine debris – and that number has risen since the last major study,” Gall said. “And in nearly 80 per cent of entanglement cases this had resulted in direct harm or death.”
The authors said only 4 percent of cases involving ingestion were known to have caused harm, but added that more study of sub-lethal impacts are needed, with areas of concern around the impact upon metabolism and reproduction.
“Encounters with marine debris are of particular concern for species that are recognized to be threatened, and with 17 per cent of all species reported in the paper as near threatened, vulnerable, endangered or critically endangered on the IUCN Red List, it is evident that marine debris may be contributing to the potential for species extinction,” said Professor Richard Thompson, one of the world’s leading experts on microplastics in the marine environment.