Drifting nets entangle birds, fish and mammals, making it difficult, if not impossible to move or eat. As our consumption of plastic mounts, so too does the danger to marine life. These materials may never become evenly diluted into a weakened mixture, and ocean processes may even concentrate some materials. Land-based alternatives for disposal also pose problems. Top of Page Raw Sewage Raw Sewage Around the world, untreated sewage flows into coastal waters, carrying organic waste and nutrients that can lead to oxygen depletion, as well as disease-causing bacteria and parasites that require closing beaches and shellfish beds Top of Page Adding New Species Alien Species For centuries, people have transplanted locally native marine species to new areas.
Most introductions are unintentional and unfortunate.
In their new homes, hitchhikers and stowaways often turn into troublemakers. Obviously, climate has a big influence on plants and animals in the natural environment, on oceans, and on human activities, such as agriculture, water supplies, and heating and cooling. The effects of climate change depend upon how much change there is, how fast it occurs, and how easily the world can adapt to the new conditions. For Questions and Comments, contact Jim Cornish , Grade Five Teacher, Gander Academy, Gander, Newfoundland, Canada. This page was last updated on July 15, 1998.