Authorities will continue removing hundreds of kilograms of debris from beaches north of Newcastle after dozens of containers fell from a cargo ship sparking fears for marine life.

Eighty-three containers fell from the YM Efficiency during surging storms last week while about 30 more were damaged.

The ship was making its way from Taiwan to Sydney when it was hit by heavy swells about 30km off the coast of Port Stephens.

Plastic, building material and other items have begun washing up raising concerns for marine animal welfare.

"I don't know what else was in these containers, if there was anything toxic, but certainly turtles and whales and large marine creatures think they are food and swallow the stuff," Port Stephens environmentalist Nigel Dique said. 

State Marine Pollution Controller Angus Mitchell said many of the damaged containers would have already sunk to the ocean floor while the others would be taking on water.

As a result he couldn't estimate how much more debris was going to escape as the containers disintegrate.

He also warned the submerged containers posed a considerable risk to boats in the area.

Authorities have asked concerned residents not to help in the clean-up but many volunteers spent time removing rubbish.

Locals have collected dozens of bags of plastic material, jars, packaged food, clocks, nappies and sanitary items.

It goes on and on and on – it is just plastic, plastic, plastic," Sims said.

The NSW Greens warned plastic poses a particular threat to marine life, including sea birds, whales, dolphins and turtles.

It has called on the state government to fast-track the clean-up to prevent further damage.

"The NSW coastline is a very busy maritime route, we should have excellent emergency response protocols but it looks like they have either failed or are grossly inadequate," Greens marine spokesman Justin Field said.

NSW Environment Minister Gabrielle Upton said the Australian Maritime Safety Authority, Roads and Maritime Services and the state's Environment Protection Agency were working with local councils to ensure all material was cleaned up.

The government said it will try recoup the cost of the clean-up from the ship's owner.

The ship's insurer has employed local company Varley to put skip bins out for residents to dispose collected rubbish and use a helicopter to find the debris floating at sea, local MP Kate Washington said.

The Australian Transport Safety Bureau is investigating the incident.