Three men face fines of up to $100,000 and two years in prison after being found guilty of whitebaiting in Fiordland National Park.
David Egerton, 54, of Ōtautau, Michael Egerton, 45, of Tuatapere and Allan Rickard, 52, of Cromwell were found guilty of taking native fish from a national park and possessing nets in Fiordland National Park.
A judge-alone trial was held this year after the three men were found to be fishing on the Waitutu River.
The National Parks Act 1980 prohibits whitebaiting in a national park without specific permission.
Department of Conservation Te Anau biodiversity principal ranger Tony Preston said the guilty verdict showed that ignoring the rules was unacceptable.
"Over the past couple of years, we have made a concerted effort to communicate exactly where that boundary is to fishers - engaging a surveyor, putting up notices in huts and speaking directly with fishers in the area. There is no room for confusion in regards to where people can and can't fish," Mr Preston said.
"The south coast boundary of Fiordland National Park is the mean high water spring mark which crosses all main rivers, including the Waitutu."
DOC had been in contact with fishers in the area and had been undergoing compliance checks for some time, he said.
"Ultimately it's the responsibility of whitebaiters to check they are legal on their chosen river - ignorance is no excuse."
The penalties for breaching the National Parks Act includes fines of up to $100,000, a two year imprisonment or both.
The trio are expected to be sentenced next month.