Feb. 15, 2002 – All recreational and commercial fishers in the St. Thomas-St. John district are advised that the U.S. Environmental Protection Agency vessel R/V Anderson, along with V.I. Fish and Wildlife Division, will be conducting ultrasonic ocean-floor mapping from Saturday through Wednesday.
Boaters and divers as well should be aware of the surveying, and avoid the designated areas.
Fishermen are urged to remove fish traps and to avoid boating or fishing in two areas during those days. Divers will accompany the survey vessel and will try to untangle lines, but removal of traps will avoid any losses, and V.I. Planning and Natural Resources requests cooperation, according to a release.
The benthic, or ocean-bottom, mapping survey complements the National Oceanic and Atmospheric Administration survey of St. Thomas and St. John nearshore and shallow-waters of some years back, results of which are available on the NOAA site. DPNR and Fish and Wildlife are grateful to EPA for providing this survey, said Dr. Barbara Kojis, director of Fish and Wildlife, as "their vessel can survey for 24 hours straight" – more than local Fish and Wildlife vessels can provide.
The present survey will allow investigation at depths below 50 feet, down to at least 110 feet, which is the depth near the artificial reef off Saba Island south of St. Thomas.
The two areas to be surveyed are:
–The artificial reef area south of St. Thomas, an area of one square mile at 18"17.5'N 64"59.0'W. This reef, in place for more than 10 years, originally was created from boats, concrete, metal barges, and the like, and all parts of it are below 50 feet depth, according to Kojis. This area is shown in the graphic at top of article.
–A large area south of St. John, beyond the 3-mile limit and including the south shelf edge and portions of the area beyond the edge. The graphic in the DPNR faxed release was not of reproducible quality, and requests to DPNR for more details were not answered.
"Benthic" is a term used to describe everything that covers a portion of the ocean bottom, "inanimate as well as animate, stationary or extremely slow-moving," said Dr. Ken Roger Uwate, Chief of Fisheries at Fish and Wildlife. Sonar images will report outcroppings of rock, corals, seagrass beds, algae communities (in particular, branch algae at depths around 80 feet and ball algae at depths to 110 feet, as described by Kojis), other habitats, and manmade deposits.
After the ultrasound images are obtained, said Uwate, "ground truthing" will be conducted in a manner similar to that done for topographic maps following aerial photography. Drop cameras and divers will be used to provide more detail of specific ultrasound images.
Eventually graphic results of the survey will be posted on the Internet.
Contact Uwate at 775-6762 for more information and exact locations being surveyed.