This stark image (of a prawn by-catch at an Irish port taken in a fine-mesh prawn trawl)shows the devastating impact of decades of intensive fishing of our seas.

An arsenal of environmental problems has been building beneath the waves, according to marine experts.

All this week the Belfast Telegraph is running a special ‘Save Our Seas’ series, revealing the devastating pressures that are draining our seas and waterways of life.

Cod stocks have crashed, as have sole and whiting. Our fishing industry now depend on catching vast quantities of prawns and that should be setting off warning signals.

This startling image shows the prawn by-catch at an Irish port taken in a fine mesh prawn trawl.

Marine expert Professor Callum Roberts, who revealed on Monday how much of our rich fishing grounds in the Irish Sea have been reduced to mud and sand, says it reveals how our prawn industry is a fishery of last resort.

“You can spot a few prawns in there, but they are overwhelmingly outnumbered by the collateral losses of juvenile fish, adult fish and seabed life that has been indiscriminately swept up, he said.

“This is a fishery of last resort. It is what remains when we have overexploited pretty much everything else, and while we continue fishing like this, there is no prospect of any recovery for the rest.

Environmental campaigners say the prawn fishery is only successful because all the predators have been fished out, leaving only scavengers.

Richard Devlin, of Northern Ireland Marine Task Force, described how the ‘blip’ during the Second World War that halted fishing on the Atlantic brought a surge in fish stocks.

“Just after the Second World War, it was said that you could walk from Ireland to New York on the backs of cod, he said.

“After less than 100 years of increasingly industrialised exploitation, habitats have already been lost, fish stocks have declined to alarming levels and the pressure on our marine world is increasing by the day.

“By the 1970s fish stocks crashed to alarming levels. We are now over-reliant on prawns because the fish stock we used to fish are gone.

“Fifty years ago we were landing the top predators cod, haddock, halibut.

“Now we are landing the scavengers with that fishing stock decline.

He and other green campaigners insist it is crucial that effective protected Marine Conservation Zones be set up as part of the forthcoming Marine Bill and this is vital to protect the health of our fisheries as well as conservation.

belfasttelegraph.co.uk