A slick, consciously unpleasant number about a mysterious plague that turns fish (from sharks to sardines) into ravening beasts ready to tear at anything that moves and that has the same effect on people incautious enough to eat the infected sea creatures. There are several memorably unpleasant scenes, including a man eaten alive by a school of bluefish and a maddened family slaughtering one another. Surprisingly for this genre, there's no happy ending. The hard-working ichthyologists whose environmental meddling precipitated the plague are unable to cure it, ending all hope of farming the oceans to provide food for a starving world. But the picture's not unremittingly bleak because girl gets boy and they sail off into the temporarily undiseased sunset. Manipulative but effective.