FOR years a remote patch of the North Pacific has served as a benchmark of global marine plastic pollution - and now it appears we have our own.

Seabirds which forage in the Tasman Sea are mistaking plastic for food, eating it and perishing on Lord Howe Island.

''The problem is here - in our backyard,'' a zoologist, Jennifer Lavers, said.

Large amounts of plastic are being recovered from flesh-footed shearwaters on Lord Howe. In the latest survey, one bird's stomach contained more than 200 pieces and others held more than 50.

The sharp-edged fragments tear internal organs and toxic substances bind to the plastic. Mercury, which is toxic to birds at four parts per million, was found in the shearwaters at up to 30,000 ppm, according to Dr Lavers.

The bird's numbers are plummeting on Lord Howe, once an Australian stronghold. Dr Lavers, of the Tasmanian Museum, said in last month's survey 95 per cent of nesting shearwaters had some plastic in their stomachs and it was hard to find living chicks.

Other seabird deaths linked to plastic are also emerging around our coastline as the UN Environment Program calls for intensified research on its impacts and Birds Australia warns it must be treated as a serious threat.

The first clear evidence of the scale of the problem came with the discovery of the ''North Pacific garbage patch'' - a gyre, or giant circular current, north of Hawaii where Asian and North American plastics gather. (read more)