Friday, February 17, 2006
Fish Counts Get Hi-Tech
Scientists are starting to use hi-tech NAVY equipment, formerly used to locate enemy subs, for fish counts, according to an article in the Sun Coast Today. Fisheries scientists are using this equipment on Georges Bank, in hopes that it proves more accurate than trawls. This torpedo shaped device snaps digital pictures of the fish using special cameras, and those images are used in combination with SONAR data to produce estimates of fish resources. The scientists feel this is more accurate than the old trawling technique because those surveys do not account for fishes that swim above or bounce off the net. Heading the effort are gradate students and faculty from UMass Dartmouth's School for Marine Science and Technology. They are using and underwater platform with a rotating SONAR device, which sends sound waves through the water. When the waves come into contact with fish, it bounces back an echo. This allows the scientists to gauge density and size of fish, but it cannot differentiate between species. The low light cameras, on the underwater vehicle mentioned above, snap pictures of the fish and the scientists pool together the data, generating estimates of fish populations.
This is good from two standpoints. One is that while trawling may catch everything, it is in no way 100% accurate. A lot of money and research is going into sonar sensing for fish, sav, everything. The technology is there and it can continue to develop to be very accurate. Second, trawling is devastating ecologically. The one thing I dislike about science research is all the death involved. Trawling kills hundreds if not thousands of fish, many of which are not the targeted species, commercial or scientific. It also changes the sea floor characteristics, removing structure, vegetation, etc. It is great that a technology is being developed to monitor fish populations that is both scientifically accurate, environmentally sound, and conservationist friendly at the same time. (Just as a reference, the photos are a reef before and after a trawl.)