Campaigners against a controversial water park at Cosmeston Lakes are considering legal action.
Over 350 people staged a protest at Cosmeston Lakes on Saturday as Aqua Park continues work to set up an inflatable assault course at the eastern lake.
Plans were given the go ahead last month despite concerns about the environmental impact of a two-month pilot scheme, which is due to begin on July 5th.
Opponents, who also held a protest last Monday, say it poses "a significant and direct threat" to local wildlife.
Aqua Park says the attraction, which will create 40 jobs locally, is being moved from Cardiff Bay because of concerns over water quality at the original site.
An online petition, set up by local resident Rachel Morgan, has now attracted nearly 6,300 signatures, while more than £1800 has been raised towards an independent ecologocial study and a water quality report.
Protest organiser Saar Lenaerts-Williams, who started an online crowdfunder, said: "Amongst other actions, we are seeking legal advice, we are undertaking thorough and independent wildlife studies and we are creating promotional materials to reach a wider audience."
Vale of Glamorgan Council insists water testing has been carried out as part of work with other agencies to ensure the lake is safe for Aqua Park visitors.
Last month, a council spokesperson said: "The eastern lake at Cosmeston has previously been used for a variety of activities – including boating, canoeing and paddleboarding – and the Aqua Park will have on-site security to reduce any opportunities for anti-social behaviour – including unauthorised camping, lighting of fires, vandalism, fly-tipping."
But Robert Curtis, a local nature activist, has accused the county council of "pushing through" the Aqua Park plans.
He said: "I have no doubt that the noise and disturbance from this attraction will have a very real negative effect effect on its wildlife."
"It is also ironic that the same councillor who proposed that the Vale of Glamorgan Council declare a "nature emergency" on 30th July 2021 is the same councillor now determined to ignore public concerns and push ahead with these badly thought out plans which will ultimately damage our precious local biodiversity."

Speaking on Bro Radio's "Ask Your" programme last month, council leader Lis Burnett denied the local authority was "putting profits first".
She said, "Income is always welcome, but this is actually a lot more than that. It's about improving what's available to local people."
"When we had the opportunity to try something out, just for one season, we felt it would be something to give us information that we needed so we could make future decisions from an informed perspective."
But the plans were criticised by the leader of the Welsh Conservative group on the council, Cllr George Carroll, who accused the ruling Labour group of being "out-of-touch" and accusing them of having "no regard for the natural environment or unique qualities that make Cosmeston so special."
Work on the new attraction began last Monday with tickets already on sale ahead of its July 5th opening - the park is due to remain open until mid-September before the pilot is evaluated.
Aqua Park founder Connor James said: "The country park is a fantastic venue for our exciting watersport experience, perfect for supervised adventure and family fun. With an exciting new course of obstacles, we can't wait to welcome visitors to our incredible new home."
"We are also really excited to be playing our part in giving people and families much-needed access to active outdoor experience, in a controlled and supervised environment to help boost their physical and mental well-being."

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