In a New Zealand first, three Otago farmers, including former All Black Andrew Hore, were yesterday convicted and fined for killing a protected fur seal on the Otago coast, a crime described by Judge Peter Rollo as a "grossly irresponsible, spontaneous act of hooliganism".

The men had name suppression until their appearance in Dunedin District Court, where they all pleaded guilty to the charges.

Andrew Keith Hore, 26, farmer, of Ranfurly, Mathew Francis O'Connell, 28, farmer, of Middlemarch, and Hamish Richard Wilson, 27, farmer, of Ranfurly, admitted taking a marine mammal, namely a New Zealand fur seal, otherwise than under the Marine Mammals Protection Act 1978 or a permit, on June 12.

While there have been previous prosecutions under the act, the court was told this was the first time anyone in New Zealand had been charged for the deliberate killing of a marine mammal.

On that charge, the three were each fined $2500, court costs of $130 and solicitors' costs of $250.

O'Connell and Wilson also pleaded guilty to possessing a firearm in a public place - Pipikaretu Bay. Both had semi-automatic shotguns.

The pair will be discharged without conviction for that if they donate $1000 to the Department of Conservation, pay $130 court costs and forfeit the guns.

Hore had also been charged with the firearms offence for possessing a semi-automatic shotgun but that charge was withdrawn by police and he was granted diversion after he paid $500 to a charity, forfeited the firearm involved and voluntarily surrendered his firearm licence for two years.

In an unusual move, police and DoC shared the prosecution of the men.

Police brought the firearm charges, while DoC prosecuted under the Marine Mammals Protection Act.

Police prosecutor Tim Hambleton and DoC prosecutor Martin Kessick said that on June 12, the three accused were part of a group of eight men fishing from a boat round the Otago Peninsula.

During the group's return to land about 4pm, the boat went within 15-30m of the shore and the three defendants started shooting at rabbits on the cliff, said Mr Kessick.

They then saw seals on the beach and cliff and started shooting at them, sending the mammals fleeing for the water.

A member of a 45-strong tourist group viewing wildlife on a nearby beach caught the incident on video. At least 15 shots could be heard on the video.

The fishing party was met by police on returning to Carey's Bay and the three men were spoken to.

They all admitted firing the shots. DoC staff found one dead fur seal the next day.

Defence counsel for Wilson and O'Connell, Anne Stevens, said both her clients were ashamed of what they had done.

The strong media and public interest that had followed the case was deterrent enough, she said.

Both men had written letters of apology to the concerned parties and had offered to do voluntary work for DoC on department land adjoining their respective farms.

Campbell Savage, appearing for Hore, said his client needed no deterrent sentence.

"There is simply no way he will ever do it again."

He agreed with Mrs Stevens that the publicity had acted as a strong deterrent.

Judge Rollo described the offending as a "grossly irresponsible, spontaneous act of hooliganism".

He said letters written by the trio showed remorse, and references showed they all took an active part in community activities and were respected members of the community.

"You are all involved in rugby at a high level - you, Mr Hore, at the highest level."

Judge Rollo said he believed the aggravating features of the offending were the number of shots fired, the close proximity to the public and the fact that the area in which they were shooting was world-renowned for its wildlife.

Andrew Hore played six tests for the All Blacks between 2002 and last year.

He played 11 games for Otago and now represents Taranaki and the Hurricanes.

O'Connell played seven games for Otago between 1997 and 1999 and has also represented Southland.

Wilson plays premier-grade rugby for Maniototo.

The boat the men shot from, the Gem, an 11m commercial cray boat owned by John Scott, of Karitane, sank last week after hitting rocks off Taieri Mouth.