February 21, 2008

To the Victor goes the Spoils

(click for larger image)

Technology is increasing available to the layperson and Landsat images give a good account of what's happening in our oceans, and sadly most of it is not good. The image above is of the Gulf of Mexico in 1992. The cloudy water that you see is the direct result of commercial bottom trawlers dragging large, heavy nets across the seafloor, denuding it of all life in their quest for a few marketable fish and shrimps. Most trawling efforts capture 20 pounds of "bycatch" in the search for commercially viable fish, and in their wake leave large, suffocating clouds of mud and sediment that may take a month to settle.

Recently the impact of bottom trawling has been seen with services like Google Earth providing large amounts of Landsat images in a public forum. John Amos, president of SkyTruth in Sheperdstown, West Virginia states: "Until recently, the impact was basically hidden from view," he continued. "But new tools -- especially Internet-based image sites, like Google Earth -- allow everyone to see for themselves what's happening. In shallow waters with muddy bottoms, trawlers leave long, persistent trails of sediment in their wake."

The bigger problem is that most bottom trawling is done in deep open waters where damage to the sediment layer is invisible to satellite imaging. "Most .. trawling happens in deep waters, out of sight. But now we can more clearly envision what trawling impacts down there by looking at the sediment plumes that are shallow enough for us to see from satellites," said Les Watling, professor of zoology at the University of Hawaii-Manoa.

Sponges, corals, and other light dependent organisms fail to survive week long periods in the darkness and this in turn knocks out the habitat and food supply of most commercially available fish.

So what can you do to help reduce this environmental destruction? Until the industrial fishing industry proves that they are acting in a more environmentally responsible manner, you can boycott eating orange roughy, Chilean sea bass (Patagonian toothfish), and all shrimps. (Keep in mind that those shrimp species that are not caught by trawling are usually farmed in shallow coastal mangroves, which also leads to tremendous, and possibly irreversible, environmental damages).

Fortunately politics are starting to listen to the scientific community and in 2005 restrictions on bottom trawling were levied in the Mediterranean Sea and in shallow water areas off the coast of Alaska. In 2006, the South Pacific Island Nations voted to stop bottom trawling in their waters, which accounts for 14% of Earth's total surface. The UN will meet later this year to decide whether to place a moratorium on the high seas, which covers 45% of Earth's surface. Lets hope they listen to the people who monitor Earth's vitals.

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