The present trends of over fishing... threaten the world's food security

Scientists Reg Watson and Daniel Pauly

They named China as the culprit, saying officials hoping to impress their political leaders had inflated the size of catches by Chinese fishermen despite the fact that some of the seas around China had long been classified as over-exploited.

They say analysts using these figures concluded that fish stocks were healthier than they really were and, as a result, had seriously underestimated the effects of over-fishing.

Fish provide a substantial portion of the world's protein needs and the study - by Canadian scientists Reg Watson and Daniel Pauly - says continued over-fishing threatens global food security.

Chinese puzzle

The only authority to keep track of worldwide fishing, the Food and Agriculture Organisation (FAO) of the United Nations, reports that global fish catches amounted to around 80-million tonnes at the start of the 1990s and generally rose throughout the decade.

The scientists, from Canada's University of British Columbia (UBC), constructed a mathematical model that predicts catch size in different ocean regions.

Our science reporter, Helen Sewell, says elsewhere in the world the figures produced by the model matched the actual catches fairly well.

However, in the case of China, the stated catch figures and the modelled figures were far apart.

Promotion strategy

The scientists say this means that China could not have been catching as many fish as it claimed.

The researchers say this led the FAO to believe that global fish catches had increased, whereas in fact they had actually been dwindling.

A spokesman at the Chinese fisheries department said staff promotions used to be made on the basis of catch figures but the department had ended the practice two years ago.

He said the Chinese Government was now paying more attention to the preservation of resources.