And they call it progress. Today's giant mechanised ships that hoover fish from the ocean depths are less effective than 19th-century sailing vessels, a study has discovered. In fact, the UK's modern fishing fleet must work 17 times harder for the same catch as its Victorian counterparts. The nets are not the problem, nor the men who haul them in. It is the fish. All the fish in the sea doesn't mean the same any more.

Over-fishing is not a new environmental problem but, like its terrestrial cousin, habitat and biodiversity loss, it is one that society finds hard to grasp.

The study, released by experts at York University and the Marine Conservation Society, paints a dismal picture of life beneath the waves. One of the first to examine records of catches landed, the research assessed the availability of fish by comparing the effort trawling vessels put in with the amount they take home – called the landings of fish per unit of fishing power (LPUP).

The job of a fisherman is never easy, but the study highlights just how much more difficult it has become as their prey dwindles. From 1889 to 2007, the LPUP declined by 500 times for halibut, more than 100 times for haddock, and more than 20 times for plaice. In the waters of England and Wales, 19th-century fishermen were landing four times as much as today. In 1937, at the peak of the UK's fishing industry, the catch was 14 times what it is now.

The figures indicate fish stocks were in decline long before a dip in catch quantity in the 1960s. This was masked by technical development and the shift to new fishing grounds.

The experts say their findings reinforce calls for reform of EU fisheries policy. They are not the first to call for such a change to protect fish. Each year, scientists at the International Council for the Exploration of the Seas issue their dire roll call of stocks and urge politicians to curb quotas. Each year, the politicians ignore the advice and send their boats out again. And with every journey, so their task gets harder.