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."

Barry’s Own Daniel White to Walk 190 Miles Back to Where His Round Table Story Began
1,300 people attend Flying Start Family Fun Day
Dispersal order put in place to tackle anti-social behaviour
Interim Chief Executive Appointed at Cardiff and Vale University Health Board
Cardiff Theatre Marks 50 Years of Service for Long‑Standing Staff Member
Council to review use of GP letters as evidence for disability claims
Plans have been put in place to redevelop a complex with more than 20 flats
Vale Council Reaccredited Under White Ribbon Scheme as Part of Ongoing Work to Tackle Violence Against Women and Girls
Two Vale Restaurants Among Those Set to Close as Whitbread Shuts Brewers Fayre and Beefeater Chains
Vale Council Issues Safety Warning After Gas Canisters Found in Household Recycling
Cogan Primary School Praised for its Inclusive Culture and Strong Leadership in Estyn Inspection
Senedd Members Call to Tackle Substance Use Stigma
Calls for Welsh Government to Match England's Pub Business Rates Cut
Caerdydd Penarth MS backs campaign to make rail station more accessible
Barry Waterfront Regeneration Project Moves a Step Closer
Age Cymru Responds to VAT cut to household electricity bills
Old Post Office in St Brides Major could be converted into a new house and set of flats
Kanishka Narayan retains AI Minister role as Burnham Signals Early Priorities
Victorian Building on Broad Street could become a new daycare centre