Research note: Relative blue crab abundance in Texas coastal waters

Populations of the blue crab Callinectes sapidus Rathbun were monitored from December 1977 to November 1981 by the Texas Parks and Wildlife Department (TPWD) using 18.3-m bag seines in fishery-independent sampling in Galveston, Matagorda, San Antonio, Aransas, and Corpus Christi bays and the upper and lower Laguna Madre. Catch rates were analyzed for differences using a three-way analysis of variance examining years, seasons, and bay systems. Mean annual coastwide rates were found to vary significantly (P= or less than 0.05) among years. Catch rates increased from 1978 to 1979 and stabilized through 1981. Greatest relative abundance of blue crabs occurred during spring and summer. Significant variations in annual coastwide catch rates were detected. These variations indicated that stratfying data into one high-catch season (spring-summer) and one low-catch season (fall-winter) would provide more precise estimates of relative abundance than yearly analyses thereby aiding in future management decisions and the analysis of the impact of such decisions.