In addition, fish often are loaded with disease-causing worms and parasites. Many of the diseases fish harbor can only be treated in humans with antibiotics. If we aren't worried about the impact eating fish will have on our own health, we should be concerned about the impact fishing has on the earth's health. The World Conservation Union lists over 1,000 fish worldwide as endangered or threatened. Over 100 Pacific salmon communities are already extinct and dozens more are seriously depleted.
Depleted fisheries have ripple effects throughout the entire marine ecosystem.
Major predator-prey situations have been changed. Loss of sea lions deprived killer whales of their primary source of nutrition and they have shifted to eating sea otters. As a result, sea otters have also declined by 90 percent since 1990, resulting in a surge by their prey, sea urchins. The environmental impact of aquatic farming is also cause for concern. First, wild stocks are displaced as introduced fish invade spawning grounds and compete for food.