Fishing company Sanford says its annual net profit is likely to be substantially lower than the about $28 million it foreshadowed in May.
That's because catches in two important fisheries are down and Greenshell mussel production is lower than planned.
Sanford says its net profit for the 12 months ending September is now likely to be between $23 million and $25 million.
Those figures are still higher than the previous year's $21 million net profit.
Sanford managing director Eric Barratt said low catches experienced in the skipjack tuna fishery in the Pacific and in the toothfish fishery in the South Georgia fishing zone was something shared by all fishing boats in those areas.
He said science shows those fisheries are stable but there will be variations in catch from year to year depending on water temperatures, seasonal conditions and weather patterns.
Mr Barratt said speculation about the reasons for the lower Greenshell mussel production includes the summer drought and La Nina weather patterns.
He said he suspects it will be a seasonal issue and production will hopefully pick up next year.