Juvenile Finfish and Blue Crab Stock Assessment Program Bottom Trawl Survey Annual Data Summary Report Series Volume 1988

Abstract

The Virginia Institute of Marine Science (VIMS) has conducted a trawl survey of the Virginia tributaries to the Chesapeake Bay dating back to 1955. Over these forty years, methods and objectives have varied according to funding sources and state and/ or federal mandates. The present thrust of the program is to provide juvenile indices of relative abundance of recreationally, commercially, and ecologically important finfish and invertebrates. In 1988, the main area of focus was as a monitoring device of the resources of the Chesapeake Bay and its tributaries, as well as a way to create juvenile indices of key target species. These measures of juvenile abundance are widely used as a key element in the management of the Atlantic States\u27 coastal fishery resources and serve as early indicators of future year class strength. In addition to the river trawl survey, a comprehensive Bay-wide trawl survey of Virginia waters, which was performed in the past with varying sampling methods, was reintroduced in 1988 as a random stratified sampling design. This design was based on depth and three 20° latitudinal regions (top, middle and bottom). The design was altered slightly beginning in 1989 to create four regions (top, upper, lower and bottom). The purpose of this change was to associate each tributary with a mainstem Bay segment. Results are shown as this altered method. The Bay survey accounted for over 70 percent of the annual sampling and two-thirds of the overall 1988 catch. The bay anchovy in 1988 continued to be the most abundant species caught in the river trawl survey and was most abundant overall. The second most abundant species, spot, was captured at near historic high levels in 1988 (the highest since 1984 ). H.ogchoker, weakfish and Atlantic croaker complete the top five species caught overall