SEASONALITY OF FISHES OCCUPYING A SURF ZONE HABITAT IN 



THE NORTHERN GULF OF MEXICO 



Timothy Modde* and Stephen T. Ross^ 



ABSTRACT 



The ichthyofauna occupying the surf zone habitat of Horn Island, Mississippi, between 1975 and 1977 

 was dominated by immature clupeiform fishes. The dusky anchovy, Anchoa lyolepis, and the scaled 

 sardine, Harengula jaguana , together constituted 80.2^'f of the 154,469 fishes collected. The greatest 

 number of fishes were collected in the late spring and summer, followed by a secondary peak in late 

 winter. Occurrence of the fishes within the surf zone is divided into three categories according to 

 seasonal utilization: spring and summer, summer only, and winter Factors affecting numerical abun- 

 dance within the surf zone differed among the most frequently appearing species. Differences in the 

 numbers of clupeiform fishes — A. lyolepis; A. hepsetus, striped anchovy; and H. jaguana — were more 

 closely associated with diel changes including tidal stage and time of day. The abundance of the Florida 

 pompano, Trachinotus carolinus, and the gulf kingfish, Menticirrhus littoralis, were more dependent 

 upon seasonal effects such as temperature. 



Relatively few studies have investigated the role of 

 exposed surf zone habitats in the early life history 

 of fishes. While Springer and Woodburn (1960) de- 

 scribed the surf zone region as an "extreme habitat 

 offering little environmental diversity," this 

 habitat does provide several benefits to fishes. Ad- 

 vantages suggested by Warfel and Merriman 

 (1944) included the abundance of food (concen- 

 trated by incoming tides), increased metabolic 

 efficiency via heat acquisition, and protection 

 from predation. 



Surf zone ichthyofaunas are numerically domi- 

 nated by relatively few species. For instance, 

 McFarland (1963) stated that 60-80% of the ich- 

 thyofauna occupying the surf regions along the 

 south Atlantic and Texas coasts was comprised of 

 only a few species. Gunter (1958) found high simi- 

 larity in species composition between Mustang Is- 

 land, Texas, and Atlantic coast surf zones and 

 suggested that the surf zone region was dominated 

 by a small group of species which remained rela- 

 tively constant over wide geographical areas. 



Much of the literature regarding shore zone 

 fishes is restricted to either descriptions of species 

 occurrence or seasonal characterizations, seldom 

 exceeding one annual cycle. Reid (1955a, b), 

 Schaefer (1967), and Hillman et al. (1977) have 



'Department of Biology, University of Southern Mississippi, 

 SS Box 5018, Hattiesburg, Miss.; present address: Department of 

 Wildlife and Fisheries Sciences, South Dakota State University. 

 Brookmgs, SD 57007. 



^Department of Biology, University of Southern Mississippi, 

 SS Box 5018, Hattiesburg, MS 39401. 



sampled the same habitats in successive seasons 

 and have observed annual changes in species com- 

 position. Fewer studies have attempted to relate 

 physical or biological parameters to the abun- 

 dance of fishes within the shallow beach habitat. 

 Gunter (1945) and Warfel and Merriman (1944) 

 attributed the distinct seasonal fluctuations in 

 fish abundance to temperature. Both Anderson et 

 al. (1977) and de Sylva,^ using multiple regression 

 analyses and crosstabulation, respectively, also 

 indicated that temperature was a significant fac- 

 tor in determining seasonal abundance of the most 

 numerous fish species. 



The present study describes seasonal and an- 

 nual variations in fish species composition and the 

 factors affecting fish occurrences within the surf 

 zone of Horn Island, Miss., a barrier island in the 

 northern Gulf of Mexico. 



METHODS 



The study area was located along the southern 

 shore of Horn Island, Jackson County, Miss. Horn 

 Island is in a chain of barrier islands lying parallel 

 to the Mississippi-Alabama Gulf coast (Figure 1). 

 The island lies approximately 14 km off the main- 

 land and has a length of 19 km with a maximum 

 width of 1.2 km. The beach is partially protected 

 from oceanic wind-driven waves by a series of sand 



^de Sylva. D. P. 1962. Fishes and ecological conditions in 

 the surf zone of the Delaware River estuary, with notes on other 

 species collected in deeper water. Univ. Del. Mar. Lab Inf 

 Serv. 5, 164 p. 



Manuscript accepted April 1980. 



FISHERY BULLETIN: VOL. 78, NO. 4, 1981. 



911 



