RESIDENTS are angry a “concrete dam” has appeared at Whipsiderry Beach, which is blocking a natural pool.
Leah Steward, who discovered the structure, says the wall has killed marine life that has been living there.
She believes someone has constructed the dam to prolong their wild' swimming in the mermaid pools.
Leah said: “I was walking my dog around to Whipsiderry on the low tide when I found that someone had built a concrete dam in the natural drainage channel of the mermaid pool, completely blocking it.
“I was shocked to see the concrete structure there.
“It looks so out of place in a beautiful natural pool. Whoever built it went to quite a bit of effort to get that amount of concrete, bricks, slate patio pieces, and block down to such a tricky site to access.
“It's sad to see that the concrete has encased and killed all the marine life that had been living in that section of the pool.”
A Duchy of Cornwall spokesperson said: “We have been made aware of an unauthorised modification to the natural environment at Whipsiderry Beach, we would appeal to the public to not carry out amendments on the beach and simply enjoy the beautiful landscape.”