mesh, 6.4 mm tail mesh, and 0.9 m doors at 18 

 stations in the Mississippi Sound and with a 12.2 

 m standard otter trawl with 19.1 mm mesh, 6.4 mm 

 tail mesh, and 1.3 m doors at 6 stations in the 

 passes and outside the barrier islands. One sample 

 was taken at each station per month, except at 

 Fort Point (station 30) where two samples were 

 taken: one with the 15.2 m seine and one with the 

 BPL. 



In the fall of 1979 and the spring of 1980, collec- 

 tions were made during National Marine 

 Fisheries Service groundfish cruises (U.S. De- 

 partment of Commerce 1979, 1980). Samples were 

 taken by the RV Oregon II in depths of 9.1-91.4 m 

 (5-50 fathom lines) from Mobile Bay, Ala., to Ship 

 Shoal, La., extending to the east and west beyond 

 Mississippi coastal waters (Fig. 2). Three succes- 

 sive 10-min tows were made at each station with a 

 12.2 m standard otter trawl with 19.1 mm mesh, a 

 1.22 m vertical opening, and 2.44 m doors, and 

 samples were randomly taken. Specimens were 

 frozen on board the ship, except ripe females which 

 were preserved in 10% Formalin 2 for future use in 

 fecundity estimates. 



In the laboratory, each fish was weighed to the 

 nearest 0.1 g and standard length measured to the 

 nearest 1 mm. If the sample exceeded 50, a sub- 

 sample of 50 was weighed and measured individu- 

 ally. The remainder of the catch exceeding 50 was 

 counted and gross weight taken. 



Salinity was determined with a refractometer 

 (accuracy of IX) at stations sampled monthly, and 

 on the groundfish cruises by titration at the Na- 

 tional Marine Fisheries Service Laboratory (U.S. 

 Department of Commerce 1979, 1980). Tempera- 

 ture was taken with a YSI Model 54 oxygen meter 

 at monthly stations and with a centigrade ther- 

 mometer on the groundfish cruises. Where a trawl 

 was used, bottom water samples were collected 

 with a Niskin or a Kemmerer bottle depending on 

 the location and vessel used. 



The length-weight relationship was calculated 

 for southern kingfish by following the procedure of 

 Rounsefell and Everhart (1953). 



Results 



Geographic Range 



The distribution of southern kingfish in Missis- 

 sippi extends from as far north as Bayou Bernard 



2 Reference to trade names does not imply endorsement by the 

 National Marine Fisheries Service, NOAA. 



(station 36) to offshore beyond the barrier islands 

 (Fig. 1). Fish were captured at all monthly sample 

 sites at some time during the year except at seven 

 stations where water depth ranged from 0.3 to 

 19.5 m. 



During the fall groundfish cruise, southern 

 kingfish were captured from 4.8 km south of the 

 barrier islands to below the Mississippi River 

 Delta and from long. 88°10'-91°25'W (Fig. 2). Dur- 

 ing the spring cruise the geographic range was 

 about the same; however, populations were denser 

 near the Chandeleur Islands and at the southern 

 tip of the Mississippi River Delta. Catches of 

 shrimp, a primary food of southern kingfish, were 

 high in these areas, indicating the fish could have 

 concentrated because of an abundant food sup- 

 ply- 



Size of the southern kingfish captured varied 



with the geographic location. Specimens 50-150 

 mm SL frequented estuaries and inshore waters, 

 while adults exceeding 150 mm SL were found on 

 the Gulf of Mexico side of the barrier islands and 

 offshore in waters as deep as 69.5 m. Distribution 

 and size of the fish captured were also related to 

 gear selectivity — trawls were used to capture 

 adults in the passes and offshore, whereas smaller 

 mesh gear types were more effective for obtaining 

 juveniles and young-of-the-year in estuaries and 

 inshore waters. Trawls accounted for 42 r /c of the 

 total catch at monthly sample sites. 



Seasonal Distribution 



A total of 1,554 southern kingfish was captured 

 from October 1979 through September 1980. The 

 numbers of fish gradually increased from De- 

 cember with a peak in February; from March 

 through September there was no apparent numer- 

 ical pattern (Fig. 3). On the other hand, the 

 monthly catch by weight peaked in April with a 

 lesser peak in January. Weight gradually declined 

 during the remainder of the year. 



Although overall catches for January and Feb- 

 ruary were high, stations in the passes between 

 the barrier islands and offshore accounted for the 

 majority of southern kingfish in these months. 

 Few southern kingfish were found in the estuaries 

 during winter, and no kingfish were landed at any 

 of the offshore stations during May, June, and 

 July. 



During the fall offshore groundfish cruise, 121 

 southern kingfish (100-280 mm SL) were captured. 

 The spring cruise was more productive with 307 

 fish (70-270 mm SL) taken. No previous data on 



429 



