An investigation is underway into a recent salmon die-off of at a south coast aquaculture site.

Fisheries Minister Gerry Byrne indicates that there will be mortality in all types of agriculture and aquaculture, and there is currently no sign that fish escaped their pens in this recent incident.

Two of eight cages were damaged in what Cooke Aquaculture says was an unusual period of stormy weather on the south coast.

The cages contained a total of about 550,000 salmon, 77,000 of which are dead.

Minister Gerry Byrne says he was informed of the incident in mid-February.

He says no escapes have been reported and there is no evidence to suggest that there have been escapes.