Microplastics pollute seafloor sediments along South East Australian Coast

Microplastics pollute seafloor sediments along South East Australian Coast

IMAS study of SE Australian coast finds highest concentration of microplastic pollution in Bicheno

BICHENO on Tasmania’s East Coast has been identified as a marine microplastic black spot in new national research.

Scientific sampling along the South East Australian coast found high concentrations of microplastics in seafloor sediments — which can be consumed by marine species and contaminate the whole food chain — even in remote stretches of coastline.

Researchers expected to find high levels of pollution close to capital cities, but the highest concentration of microplastic filaments in the nation was detected in the Tasmanian fishing and tourist community.

The Institute for Marine and Antarctic Studies scientists tested 42 locations in NSW, Victoria, South Australia and Tasmania and found an average of more than three plastic filaments or particles in every millilitre of marine sediment.

The locations sampled included Sydney Harbour, Jervis Bay, Eden, Port Phillip Bay close to Melbourne and towards The Heads, Port Adelaide and the coast south of Adelaide, Hobart’s Derwent Estuary and Tasmania’s East Coast.

IMAS researcher Dr Scott Ling, who led the study published in the journal Marine Pollution Bulletin , said the discovery of microplastic pollution at every location showed how easily plastic was dispersed in the marine environment.

Dr Scott Ling, from Hobart’s Institute for Marine and Antarctic Studies, said researchers were surprised by the quantity and wide dispersal of microplastics in marine sediments right along the South East Australian coast. Picture: SUPPLIED

“We were surprised by both the quantity of microplastics we found in marine sediments and their wide dispersal everywhere we looked along the South East Australian coast,” Dr Ling said.

“Our study took samples of marine sediments from depths between five and 13 metres at sites close to the major population centres as well as remote sites on the NSW South Coast and Tasmania’s East Coast.

“While we expected to find high levels of pollution close to the major capitals, we did not expect to find similar concentrations far from urban centres.

A microplastic sample from Derwent Estuary. Picture: BOUDEWIJN ZWEEKHORST

“In fact, the highest concentration of 12 microplastic filaments per millilitre of sediment was from Bicheno on Tasmania’s East Coast.”

The report said the microplastics found in sediment around Bicheno were dominated by what appeared to be plastic rope fibres, a material used heavily in maritime activities.

Dr Ling said microplastics were created both by the fragmentation of larger pieces of plastic in the ocean and were manufactured as microbeads for use in cosmetics, or microfibres in clothing.

“Because these filaments are often produced by household washing machines, and particles are transported with litter and by industrial discharge, we expected a stronger concentration of microplastics close to population centres but there was no such correlation,” he said.

Dr Ling said further research was needed to establish at what rate marine fauna were digesting these materials, and the impact they were having on individuals, populations and communities.

Source: HELEN KEMPTON, Mercury