Boris Worm of Dalhousie University in Nova Scotia, Canada, led the international team that did the study. Professor Worm says species have recently been disappearing from oceans at increasing speed. At this rate, he says, all seafood species could collapse by 2048 and seafood supplies from the world's ocean could be almost gone by then. Other studies have also warned about the dangers of overfishing and the effects on ocean environments. But not everyone thinks the oceans are likely to be empty in fifty years. Some scientists said parts of the world do have problems, but others are doing a good job of protecting fish populations. Government officials in several countries with large fishing industries also questioned the research. The study appeared earlier this month in Science magazine. The researchers say damage to oceans affects not only fish populations but also the productivity of ecosystems. These complex systems help control water quality. The scientists say the loss of different kinds of sea life appeared to increase the risk of fish kills and beach closures from harmful algae growth. The scientists examined the results of thirty-two experiments and observed forty-eight protected areas. They also looked at records of catches worldwide. They studied records from the United Nations Food and Agriculture Organization for nineteen fifty to two thousand three. And they examined archeological information and other historical records for twelve coastal areas. That research reached back over a thousand years. Boris Worm says the findings were, in his words, "beyond anything we suspected." But he also said the situation is not too late to correct. He said that with good fisheries management, some species could completely recover in three to ten years. The research led by Boris Worm   _  .
was conducted by scientists from Canada referred to information of many countries lasted from 1950 to 2003 referred to records dating back to over 1,000 years ago.