Bottom-trawling makes for skinny cod
Trawling the sea floor for bottom-dwelling fish is making cod skinnier, scientists have found.
The study looked at the size of cod, lemon sole, megrim and haddock in the Celtic Sea south of Ireland.
It found these fish tended to be smaller in heavily trawled areas and in worse general health.
The scientists, led by Samuel Shephard of the Galway-Mayo Institute of Technology in Ireland, concluded bottom-trawling removed the prey of such fish, like shellfish, sea-urchins and crabs.
These negative changes meant that fishermen ended up trawling for less valuable fish with smaller fillets, they said.
Writing in the journal, Proceedings of the Royal Society B, they warned that the study "implies that bottom trawling can reduce habitat-carrying capacity".
The practice "is likely to further diminish fisheries productivity and impair the recovery of threatened stocks and ecosystems."