Poaching of southern bluefin tuna was a problem once again for the industry this season.
Last year, the local tuna industry said damage done by poachers to the fishery was the worst it had ever seen.
Australian Southern Bluefin Tuna Industry Association chief executive officer Brian Jeffriess said poaching was again a problem for the industry at the start of the year.
"At the start of the tuna season, the poaching activity appeared to be higher than normal, particularly on the farms closest to eastern Boston Island," he said.
"However, it reduced considerably from March and April."
Mr Jeffriess said the reduction in poaching this year was almost certainly due to the dismissal of another employee on a tuna farm who had been providing information to poachers, and increased surveillance at key landing areas away from Port Lincoln.
"In 2014, this surveillance of landing areas will start as soon as the first tuna are brought in," he said.
"The surveillance will also be continuous, rather than just random."
Last season, Mr Jeffriess said the poachers caused significant damage to farming infrastructure as they cut the high nets to gain access to the tuna.
Cutting of the pontoon nets allows seals to get into the pontoons and poachers can also cause significant stress to the fish.