Beijing – For years, marine scientists have warned that too much fish has been caught from the world’s oceans and have called for drastic measures to curb widespread overfishing. Yet those worries seemed to be undercut by the reported global yield of marine fisheries, which continued to rise through the 1990’s, particularly because of large increases reported by China. Now a detailed analysis of fishery statistics has found evidence of substantial overreporting during the last decade, mainly by China. In the past, the country’s lower officials had strong incentives to say they had met the government’s rising targets for fish catches. The apparent result was that they simply exaggerated the count to match their goals. So, instead of rising by an average of 330,000 tons per year since 1988, as recorded in United Nations data, the world’s catch has actually declined by an average of 360,000 tons per year, according to a study in the current issue of the journal Nature. The study raised doubts about the ability of fisheries to meet growing global demand for food, marine experts said, and it strengthened the case for sharp reductions in fishing fleets, a contentious issue in many regions. Over the last decade, as the reported catch climbed beyond the roughly 80 million tons a year that scientists saw as the outer limit of sustainable fishing, fishing industry representatives fought against stringent limits and cited the apparently continued growth in catches as a reason to keep expanding fleets. The authors of the study, Reg Watson and Daniel Pauly, fisheries scientists at the University of British Columbia in Vancouver, noted that the greatest effect of inflated catch statistics was to cause complacency about the state of the world’s marine stock and about overfishing. Spurious data, they suggest, have also deterred proper regulation. "A lot of people thought we could feed more people from the sea," Mr. Pauly said. "But it’s over." The only source of global fishery data is the United Nations Food and Agriculture Organization, which must rely on numbers provided by member governments.