Small flat fish with grey scales were found dead near the waters of Harwood and Portobello this week.
The fish were identified as Ray’s bream, a mid-water fish not normally found in Otago Harbour.
Ministry of Primary Industries regional compliance manager Garreth Jay said it was making inquiries after receiving calls from recreational fishers who saw many of the fish washed up on the Otago Peninsula.
There was no indication or evidence that it was the result of fishing activity.
Local residents reported they had seen the fish stranding on the outgoing tide, he said.
Ray’s bream are generally found in offshore waters and are a common bycatch when fishing for groper and bluenose and are often caught in the Bay of Plenty and Cook Strait waters.
They usually are not found in Otago Harbour or in shallow coastal waters.
There were many factors that could contribute to an event like this, including climate change or weather conditions, he said.
There had recently been a prolonged period of northeast swells and winds.
The conditions were typical for La Nina, a naturally occurring global climate cycle which affected weather patterns around the world, including New Zealand.
Those conditions may have caused the juvenile fish to be washed further south and caught in the shallow gradient beaches of Otago Harbour and Long Beach, and then stranded on the outgoing tide, he said.
Ray’s bream, also known as The Atlantic pomfret, are a white meat fish known for being good value eating.
It is usually found in the Atlantic, Indian and South Pacific Oceans at depths down to 1000m.
They measure about 40cm to 100cm as adults.
