Guernsey diver John Fallaize said he had seen a shift in wildlife present in island waters, such as comber fish, which were usually found in the Mediterranean.
“This small fish is guaranteed on every dive irrespective of the locations around the islands,” he said.
Fallaize said he noticed more jellyfish, including mauve stingers which were also more commonly found in warmer European waters.
“More dolphins [are] being seen and from what I have seen they have been eating the jellyfish as there is no mackerel about either,” he said.
Fallaize added octopus had been “more plentiful and of a slightly smaller size than the last two years”.
Harris said the surge in numbers in recent years were due to “milder winters so there’s not a die-off event which we have previously had in the 1960s”.
With marine experts suggesting bluefin tuna are more likely to be seen, deputy Marc Leadbeater thinks Guernsey should be catching the fish, something that is currently not legal.
To allow the landing, the island needs a quota from the Department for Environment, Food & Rural Affairs (Defra) in the UK.
“I’d like to see us have access to some tuna quota, clearly Jersey’s moved ahead of us in that direction at the moment because they’ve got catch and release and commercial tuna quota from Defra,” Leadbeater said.
He said it would be a vital decision in helping to keep the island’s fishing industry afloat.
