A Lot of What We Do Impacts the Sea

Habitat alteration, simply put, is a change to a particular environment. What is unclear from its designation, however, is the adverse affect changes — big or small — have on the broader environment and related plant and animal life. According to The Nature Conservancy, habitat alteration, along with invasive species, are the two main causes of fish extinction.

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Furthermore, in the United States 40 percent of fish and amphibians, 50 percent of crayfish and 70 percent of mussels are endangered due largely to habitat alterations resulting from such practices as bottom trawling, anchoring, coastal development, and cyanide and blast fishing. These activities create change with devastating effects on marine ecosystems.

Once restricted to sandy, flat-bottom areas, technical innovations such as rollers and rock-hopper devices have allowed for bottom trawling at depths as great as 6,000 feet. This practice entails the dragging of massive bag-shaped nets along the ocean floor to collect targeted fish. But they damage sensitive and complex deep-sea ecosystems along the way. With some rock-hoppers weighing as much as 300 pounds, coral forests, rock pinnacles and boulder-covered areas — great places for fish to hide, feed, and lay eggs — face serious long-term damage.

A quick pass of a trawl and one sweep can kill non-targeted marine life such as bottom-dwelling invertebrates that can take three, five or more years to recover. Additionally, fishing nets can become lodged on rock outcroppings, which in turn can wear away the polyps and upper tissue layers of the coral reef reducing useable habitat for fish, mammals and birds. According to the Pew Oceans Commission, fisheries in Northern California and New England are typically trawled more than once a year.

Article continues: http://www.ecori.org/green-opinions/2011/1/16/a-lot-of-what-we-do-impacts-the-sea.html