A fishing boat skipper forced to release an estimated 30 tonnes of jack mackerel to save six dolphins caught in his net, is being praised for his actions by Sanford Ltd - and a boatload of recreational fishers who saw the drama unfold.

'They tried their hardest to get them out of their net without losing their catch, because they had a huge amount of fish in there,” says recreational fisher Paul Bowyer.

'It was all boiling up when we arrived and there were dolphins around the outside. The net was already round by then.

'We don't know how the dolphins got in there. We arrived on site looking for tuna and the dolphins were in the net.”

Paul says there were about five dolphins in the net. The San Columbia crew used the purse seiner's dory to try and round the dolphins up and herd them towards a gap they created in the net, but the dolphins just swam around or under.

About 45 minutes after recreational fishers arrived, the San Columbia released the catch.

'One guy was yelling, swearing, and carrying on, he must have been the skipper,” says Paul.

The San Columbia was fishing on the middle ground between Motiti and the Mount last Thursday. It was about sunset when the recreational fishers arrived on scene and approaching dusk when the catch was released.

Sanford Ltd general manager corporate communications Fiona MacMillan says the San Columbia was purse seine fishing off the Tauranga coast when half a dozen dolphins swam into the net.

'The crew were determined not to hurt the dolphins in any way if at all possible and they set about trying to free them by lowering the sides of the net. Unfortunately this did not encourage the dolphins to swim out, so the skipper faced a tough choice at that point,” says Fiona in a statement from the company.

'He either took further steps to try and free the dolphins and risk losing the catch of 30 tonnes of jack mackerel, or he faced the prospect of killing the dolphins.

'He believed that his first priority was to try and save the dolphins. So he made the decision to release one end of the net at the bow and that enabled all the dolphins to swim away, totally unharmed. In the process all the jack mackerel accidentally escaped too.”

While no fish were caught or harmed, Sanford is now required to report the jack mackerel as catch and it counts against the company's annual catch entitlement for this species, says Fiona.

'Sanford supports what the skipper of the San Columbia and his crew did in this situation. The skipper felt that he simply had no viable choice. He believes that any New Zealander in his position would have done the same and Sanford agrees with him.

'The skipper is a very experienced fisherman who has been fishing for 40 years and he goes to a lot of trouble to avoid fishing when dolphins are present, as he had done several times earlier on that day.”

While 30 tonnes of fish is a potentially significant financial loss, Fiona says Sanford's focus is on sustainability.

'Sanford supports the skipper and believes he did the right thing in saving the dolphins and all the fish. Costs comes second in a situation like this."