Ken Schwarzenberg, 53, of Princes Highway, pleaded guilty in the Warrnambool Magistrates Court yesterday to possessing undersized abalone, obstructing a fisheries officer and failing to comply with a lawful direction.

He was not convicted, fined $400 and ordered to pay $501.40 costs while the possessing undersized abalone charge was proven and dismissed. The maximum fine for obstructing an officer is up to a $14,000 fine.

Fisheries officer Troy Duthie said that on December 29 last year Mr Schwarzenberg and another man were seen leaving the water off Ocean Drive, Port Fairy.

They were intercepted by fisheries officers who found Mr Schwarzenberg had one crayfish and five abalone. Three of the abalone were just under size, measuring 12.8cm and 12.9cm, instead of the 13cm minimum. 

Mr Schwarzenberg then returned the undersize abalone to the water despite being directed a number of times by fisheries officers that the abalone had to be photographed and seized. 

He admitted catching the abalone and said he was unable to measure them properly because of the rough sea conditions. 

Mr Schwarzenberg later apologised for his behaviour, saying he had a bad day after having a disagreement with his wife.

Defence counsel Alex McCulloch said Mr Schwarzenberg was a keen recreational diver and he had been teaching his son how to dive at the time of the offending.

Magistrate John Lesser said fisheries rules were about protecting the environment, which was a benefit for professional fishermen like Mr Schwarzenberg.

He said it was unacceptable that the defendant had ignored the instructions of the fisheries officers, something the magistrate found inexplicable.