Growth of five fishes 



in Texas bays in the 1960s 



Gary C. Matlock 



Texas Parks and Wildlife Department 



4200 Smith School Road, Austin, Texas 78744 



The estuarine sport and commercial 

 fish fisheries in Texas have histor- 

 ically relied upon five species: black 

 drum Pogonias cromis, red drum 

 Sciaenops ocellatus, sheepshead Ar- 

 chosargus probatocephalus, south- 

 ern flounder Paralichthys lethostig- 

 ma, and spotted seatrout Cynoscion 

 nebulosus. Regulation of these fish- 

 eries dramatically increased as hu- 

 man demand for fish generally in- 

 creased through the 1980s. For 

 example, the sale of red drum and 

 spotted seatrout caught in Texas 

 was prohibited in 1981, use of nets 

 in coastal waters was prohibited in 



1988, and size, bag, and possession 

 limits were imposed for each species 

 by 1988. Growth information was 

 used in selecting appropriate regu- 

 lations for optimizing yield and sus- 

 taining recruitment. However, com- 

 prehensive, coastwide growth rates 

 were available only for red drum, 

 black drum, and spotted seatrout 

 caught in the late 1970s and 1980s 

 when exploitation was extremely 

 high (Doerzbacher et al. 1988, 

 Green et al. 1990). Potential yields 

 may be underestimated when based 

 on growth rates obtained when 

 fishing mortality is high. Tagging 



Figure I 



Location of Texas 

 bay systems. 



data from which growth param- 

 eters could be estimated for those 

 species had been collected sporad- 

 ically from the late 1950s through 

 the early 1970s (Green 1986) when 

 fishing effort was presumably lower 

 than in the 1980s, but these data 

 have not been examined. The objec- 

 tive of this study was to describe 

 quantitatively the growth of black 

 drum, red drum, sheepshead, south- 

 ern flounder, and spotted seatrout 

 tagged in the 1960s. 



Methods 



Data on total length (TL, mm) at 

 tagging and recapture, and the 

 number of days free until recapture 

 for five fishes— black drum, red 

 drum, sheepshead, southern floun- 

 der, and spotted seatrout— tagged 

 by the Texas Parks and Wildlife 

 Department (TPWD) in Texas bays 

 (Fig. 1) and recaptured during the 

 period 1950-75 were obtained from 

 Green (1986). No length data were 

 available for fish tagged in the 

 Matagorda Bay system, however. 

 Data resulted from a variety of pro- 

 jects designed to obtain life history 

 information on fishes, mainly red 

 drum and spotted seatrout. Fish for 

 tagging were obtained using rod 

 and reel, trotlines, and trammel and 

 gill nets. Monel strap tags and in- 

 ternal abdominal tags were primar- 

 ily used. The release of tagged fish 

 and requests for information con- 

 cerning recaptured fish were adver- 

 tised through the news media and 

 posters placed in areas frequented 

 by fishermen. Non-monetary re- 

 wards of various types were usual- 

 ly offered for returned tags. Addi- 

 tional details are contained in Green 

 (1986). The mean daily growth rate 

 (G) was used to examine the suit- 

 ability of the von Bertalanffy model 

 for describing growth of each spe- 

 cies. The growth rate was calcu- 

 lated as follows: 



Manuscript accepted 9 March 1992. 

 Fishery Bulletin, U.S. 90:407-411 (1992). 



407 



