An elderly farmer says he has been made "to feel like a criminal" after creating a wildlife pond on his land.
Fred Meakin, 76, was forced to fill in the 20m (65ft) pond near his home at Brynteg, Anglesey or face a £5,000 Welsh Government fine.
The pond could pose a risk to rare fenland species, environmental officers warned.
But Mr Meakin said he was shocked by the decision.
"It's upset me terribly. They've made me feel like a criminal," he said.
The Welsh Government issued Mr Meakin with a remediation notice after doing an environmental impact assessment on the pond.
A government official said the land was classed as "semi-natural," meaning certain environmental regulations apply.
"The regulations are there to protect its natural habitats from changes which could endanger rare species of flora and fauna," they said.
Land owners should contact the Welsh Government before making any changes to semi-natural land, they added.