Google Earth improves image for catching fish

One type of fishing trap known as weirs that jut out from coastlines is now facing scrutiny as Google Earth images reveal the traps be snaring six times as many foish than what is officially reported. Using satellite imagery from Google Earth, University of British Columbia researchers estimated that there were 1,900 fishing weirs along the coast of the Persian Gulf during 2005 and that they caught approximately 31,000 tonnes of fish that year. The official number reported by the seven countries in the region to the United Nation's Food and Agriculture Organization was 5,260 tonnes. Fishing weirs are semi-permanent traps that take advantage of tidal differences to catch a wide variety of marine species. The basic purpose is to capture fish by limiting their movement without greatly impeding water flow. In the case of intertidal weirs (like those found in the Persian Gulf), fish swimming parallel to shore at high tide encounter the "wing" and invariably try to escape by swimming into deeper water, eventually entering a smaller enclosure where they are captured by receding tides.



http://www.enn.com/wildlife/article/46733