Man-made debris putting marine animals at extinction risk

Man-made debris such as plastic and glass are contributing to potential extinction of some of the already endangered marine species, a study says.

"It is evident that marine debris may be contributing to the potential for species extinction," said professor Richard Thompson from the Plymouth University in Britain.

From reports recorded from across the globe, the researchers found evidence of 44,000 animals and organisms becoming entangled in, or swallowing debris.

"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," Sarah Gall from the Plymouth University noted.

"And in nearly 80 per cent of entanglement cases this had resulted in direct harm or death," Gall added.

The authors said that while only four percent of cases involving ingestion were known to have caused harm, further study of sub-lethal impacts are needed.

The researchers presented evidence collated from a wide variety of sources on instances of entanglement, ingestion, physical damage to ecosystems, and rafting - where species are transported by debris.

Plastic accounted for nearly 92 percent of debris, and 17 percent of all species involved were found to be threatened or near threatened on the IUCN (International Union for Conservation of Nature) Red List, including the Hawaiian monk seal, the loggerhead turtle and sooty shearwater.

In total, they found that 693 species had been documented as having encountered debris, with nearly 400 involving entanglement and ingestion.

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.

Plastic rope and netting were responsible for the majority of entanglements and plastic fragments were the highest recorded substance for ingestion.

The study was published in Marine Pollution Bulletin.