Fish stocks changing in warmer seas

August 03, 2014 - 1:00:25 am

LONDON: Cod and chips could soon become a dish of the past, as Britain’s waters become ever warmer. Marine experts have warned that rising sea temperatures are transforming the makeup of fish stocks in our coastal waters.

Where cod and haddock once thrived, sea bass, hake, red mullet and anchovies are now being caught in rising numbers. If Britain wants sustainable fisheries round its shores, it will have to turn to these for the fish suppers of the future, they add.

“We are going to have to be much more flexible about the fish we eat as our coastal waters continue to warm,” said Professor Richard Lampitt of the National Oceanography Centre, Southampton.

“The idea that the cod is the only fish worth eating is part of a mindset that we can no longer support.”

Marine scientists have found that the seas round the UK have risen in temperature by a remarkable 1.6C since 1980, a jump that is almost four times the global average rise for ocean temperatures. Britain’s position on the relatively shallow continental shelf of Europe, and the enclosed nature of our seas – the North and Irish seas and the Channel – have intensified the impact of global warming.

As a result, our waters are now attracting more and more unexpected visitors, including dolphins and a pair of humpback whales – a rarity for UK waters – that were seen in the Irish Sea last month. Other changes have been even more profound. “Over the last 35 years, 15 of the 36 species surveyed in the North Sea have shifted latitudes,” said oceanographer Professor Callum Roberts of York University. “The average shift was 300km north.”

Cold-loving fish have moved north towards Iceland and the Faroe Isles while warm-water fish have moved up from the south to take their place, added Roberts. Cod is now hardly found in our waters, for example, while the John Dory, a narrow-bodied fish with a long, thin jaw that was once found only near the south-west tip of England, has colonised the North Sea as far as Scotland.

“The trouble is that our national appetite for fish is still monopolised by the ‘big five’: cod, haddock, tuna, prawns and salmon,” said Professor Stephen Simpson of Exeter University. “But very few of these are caught in our waters. So we have to import them – cod from Iceland, tuna from the tropics, for example – or they are grown on fish farms, like the salmon. Only haddock survives in some northern UK waters.”

At the same time, however, stocks of gurnard, sea bass, John Dory, ling, hake, sardines and other fish are spreading from the south into British coastal waters. “Unfortunately, UK fishermen who are bringing them in cannot find any market for their catches in the UK.

“As a result they having to sell them to Spain and other European countries,” said Simpson.

“We should be eating these fish. They come from our waters today and if we ate them instead of cod we would no longer have to import so much fish. But we won’t do that until we change our attitudes to the fish we eat in Britain. We are out of date. It is as simple as that.”