Document Type



Virginia Institute of Marine Science

Publication Date



Special Scientific Report No. 124 V. 1996



The Virginia Institute of Marine Science (VIMS) has conducted a trawl survey dating back to 1955. Over the years methods and objectives have varied according to funding sources and state and/or federal mandates. The present thmst of the program is to provide juvenile indices of relative abundance for recreationally, commercially, and ecologically important fish and invertebrates. These measures of juvenile abundance are widely used as a key element in the management of the Atlantic States' coastal fishery resources. Estimates of juveniles ( age-0) have proven to be a reliable and early indicator of future year-class strength. A review of previously available indices of juvenile abundance for important fishery resource species of the Chesapeake Bay by the Chesapeake Bay Stock Assessment Committee (CBSAC), a federa1/state committee sponsored and funded by the National Oceanic and Atmospheric Administration (NOAA), resulted in the recommendation that, "a unified, consistent trawl program should be one of the primary monitoring tools for finfish and crab stock assessment." (Chesapeake Bay Program Stock Assessment Plan, Chesapeake Executive Council 1988). Several comments should be noted for the 1996 sampling year. The survey goal of a complete random stratified sampling design was accomplished in 1996 with the start of a RSD survey of the James River in March. Large rain/flood events associated with a winter storm in January, and tropical storms Bertha (June) and Fran (September), resulted in one of the largest annual flow rate ever recorded in the Chesapeake Bay. These events, along with a mild winter and lower than normal spring and summer temperatures may have had an effect on the lower catches of silver perch, summer flounder, and penaeid shrimp. However, other species, such as blue catfish, spottail shiners, and spotted hake showed increase catch rates. Additionally, the spawn of both white perch and striped bass seemed to be very successful, with record numbers of juveniles (less than 30 mm) being caught in June and July. The purpose of this summary is to provide an accurate account of trawl survey sampling performed during the calendar year 1996. Previous volumes of this series have served as excellent reference guides to resource managers, scientists, academics, as well as the general public. Since there are other venues which presently detail specific results of these data (Geer and Austin, 1996a), conclusions are kept at a minimum in order to provide the most information in the available space.