Plaid Cymru has backed calls to turn Barry's Old Harbour into a local nature reserve.
At a meeting last Tuesday, the council's Place committee said it backed the idea in principle and called on officers to work with local environmental groups, such as Barry Action for Nature, to address risks to wildlife in the area.
The petition noted concerns raised about the impact of sewage pollution at the harbour, as well as "irresponsible" dog walkers and jet skiiers.
The saltwater marsh - one of the rarest habitats in the UK - supports listed speices such as curlew and whimbrel in the winter, along with other rare birds.
Two Baruc ward councillors told a committee meeting that designating reserve status at the Old Harbour could have a positive impact on nature and engagement with local residents.

Cllr Mark Hooper said: "The Vale of Glamorgan Council declared a nature emergency in July 2021, so it is a no-brainer than we should have a programme of new local nature reserves."
"This is a local designation, supported by the local council, which engages with residents to support nature. Nature doesn't know or care what resources the Vale Council has, and has been substantially diminished in recent years."
"We should be looking to declare this local nature reserve in principle, whilst better understanding the resource this requires and look in particular at grants that can support us in achieving these goals."
"For many decades, the Cliff Woods/Golden Steps and Cwm Talwg have been declared as local nature reserves, so why not Barry Old Harbour, as well as other locations in the Vale such as Rhoose Point?"
Cllr Steffan William added: "I welcome the focus on the Old Harbour. We need to protect this area from pollution. I've always understood the grasses and saltmarshes to be a unique habitat and I would like a proper audit of everything within this area."
A Vale of Glamorgan Council spokesperson told Bro Radio News: "The council's Place scrutiny committee has recommended that additional work is carried out into the possibility of designating the Old Harbour site in Barry as a local nature reserve."
"This work will also consider whether other potential sites could also receive this classification. Any immediate risks to wildlife will be identified and addressed with Dwr Cymru invited to attend the next committee meeting for a further discussion."
"The matter will also be referred to the council's Cabinet for further consideration."

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