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Stone zone: Rebecca Morris and Anthony Luck install a pot along the harbour sea walls. Photo: James Brickwood

Resembling cut-in-half flower buckets, a series of marine pots are being fastened to sea walls in Sydney's waterways in an attempt to attract starfish and crabs back to the battered urban environment.

Fifty per cent of the city's natural foreshore has been replaced by sea walls to protect the growing number of coastal parks and property development. The artificial structures are gradually destroying the habitats of marine species.

PhD candidate Rebecca Morris has collaborated with a team of University of Sydney marine ecologists to research how the pots can act as substitute rock pools for algae, snails, starfish and crabs to live in.

"I would like to raise awareness about engineering artificial structures to make them more environmentally friendly, and for councils to consider ecological enhancement when building new sea walls," Ms Morris said.

Over the course of her three-year PhD she intends to compare the biodiversity at the sea wall with attached pots at Blackwattle Bay to the closest natural rock walls at Mrs Macquaries Point.

Last week Ms Morris was awarded almost $11,000 from the City of Sydney's Environmental Grants Program which she intends to spend on cameras to track mobile predator activity around the pots.

Anthony Luck, a garden product manufacturer, tested several pot designs to find the most durable option, as previous models that were set up in other council areas were lost to wave action.

"We trialled a lot of cement mixtures,'' said Mr Luck.