DISTRIBUTION, ABUNDANCE, AND SIZE OF PENAEID SHRIMPS 

 IN THE ST. ANDREW BAY SYSTEM, FLORIDA 



Harold A. Brusher and Larry H. Ogren^ 



ABSTRACT 



Shrimp collections were made every 2 weeks at 12 stations in varying depths (1.5-12.2 m) of the St. 

 Andrew Bay system, Fla., from September 1972 through August 1973. The eight species of penaeid 

 shrimps caught in 312 trawl hauls were, in decreasing order of abundance: pink shrimp, Penaeus 

 duorarum; broken-neck shrimp, Trachypenaeus similis; rock shrimp, Sicyonia brevirostris; rock 

 shrimp, S. dorsalis; broken-neck shrimp, T. constrictus; brown shrimp, P. aztecus; white shrimp, P. 

 setiferus; and rock shrimp, S. typica. Of the total catch of penaeids, 57.7% were of the genus Penaeas, 

 22.6% oi Sicyonia , and 19.7% oi Trachypenaeus . Penaeids were more abundant in the sections of the 

 bay system close to the Gulf of Mexico. Seasonal abundance varied for each species. Shrimps of the 

 genus Penaeus were larger in deeper sections of the bay. The hydrological characteristics of the St. 

 Andrew Bay system are much more similair to the waters of the Gulf of Mexico than are those of other 

 estuaries of the northern gulf This similarity probably accounts for the relatively high abundance of 

 shrimps of the genera Trachypenaeus and Sicyonia in the bay system. Also, this similarity probably 

 delays the gulfward migration of shrimps of the genus Penaeus and accounts for their large sizes in 

 the system. 



Personal observations made on exploratory col- 

 lecting trips and on cruises aboard shrimp trawl- 

 ers within the St. Andrew Bay system in north- 

 west Florida had led us to believe that some 

 species of marine organisms normally found in 

 offshore waters of the Gulf of Mexico occurred 

 commonly within the system. For example, 

 penaeid shrimps of the genera Trachypenaeus 

 and Sicyonia, which are rare in bay systems of 

 the northern gulf, were observed frequently. Also, 

 shrimps of the genus Penaeus appeared to be 

 much larger within the St. Andrew Bay system 

 than other estuarine areas. It thus appeared to us 

 that the penaeid shrimps of the St. Andrew Bay 

 system were unusual in terms of species composi- 

 tion and size. 



Although utilization of estuarine waters by 

 populations of shrimps of the genus Penaeus is 

 well known (Lindner and Cook 1970; Cook and 

 Lindner 1970; Costello and Allen 1970), the 

 abundance, distribution, and size are not com- 

 pletely described for all penaeid species within 

 many estuarine waters. This information is espe- 

 cially lacking along the northwest Florida coast. 

 The objectives of our study were to estimate these 

 parameters for penaeid shrimps in the St. An- 

 drew Bay system. 



'Gulf Coastal Fisheries Center, Panama City Laboratory, Na- 

 tional Marine Fisheries Service NOAA, Panama City, FL 

 32401. 



STUDY AREA 



The St. Andrew Bay estuarine system is lo- 

 cated on the northwest coast of Florida between 

 lat. 30°00' and 30°20'N and long. 85°23' and 

 85°53'W. The system consists of four bays — 

 North, West, East, and St. Andrew (Figure 1) — 

 with mean depths of 1.8, 2.1, 2.1, and 5.2 m, re- 

 spectively, and covers an area of 280 km^ 

 (McNulty et al. 1972). Various aspects of the 

 physical and biological characteristics of the St. 

 Andrew Bay system have been presented by 

 Ichiye and Jones (1961), Waller (1961), Vick 

 (1964), Hopkins (1966), Salsman et al. (1966), 

 Cosper (1972), and McNulty et al. (1972). 



GUIF OF MEXICO 



Figure l. — Location of sampling stations in the St. Andrew 

 Bay System, Fla. 



Manuscript accepted July 1975. 

 FISHERY BULLETIN: VOL. 74, NO. 1, 



158 /S^^-/4(a. 



1976. 



