Boris Worm of Dalhousie University in Nova Scotia ,prefix = st1 /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 could collapse by 2048 .        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 tears . Some scientists said parts of the world do have problems , but others are doing a good job of protecting fish populations . Government officals 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 f fish kills and beach closures from harmful algae growth .        The scientist 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 from nineteen fifty to two thousand three . And they examined archeological information and other historical records for twelve coastal areas . That research 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 . Which of the  following isn't the damage to the oceans ?
The species of fish in the oceans is reducing . Sea water is polluted Sea Water quality is improved Less productivity of ecosystems