Incidental occurrence of bay scallops in texas research ponds

Bay scallops (Argopecten irradians) were discovered in 0.4- and 0.8-hectare earthen research ponds at the Texas Parks and Wildlife Department’s Perry R. Bass Marine Fisheries Research Station near Palacios, Texas. These ponds were filled with unfiltered Matagorda Bay water during April 1990 and were drained on 19 September and 8 October 1990, respectively. Mean surface water temperatures and salinities were 27.1°C and 27%o for the 0.4-hectare pond and 26.6°C and 2891» for the 0.8-hectare pond. Mean total shell lengths of bay scallops harvested were 37 mm in the 0.4-hectare pond and 53 mm in the 0.8-hectare pond. One thousand live bay scallops were moved to the bottom of another 0.4-hectare pond for overwintering, and four 6-mm-mesh plastic cages containing 50 scallops each were suspended in the pond. By April 1991, 50% of the caged scallops had survived, but survival was 0% by May. When the pond was drained on 6 December 1991, none of the 1,000 bay scallops stocked on the bottom had survived.