Table 3. — Monthly size distributions of Gulf menhaden in 

 East Bay and East Bay River, April-September, 1971. 



Size 



Apr. 



May June July Aug. Sept. 



more than 1 mile (1.6 km) from the freshwater- 

 low salinity zone. As the young increased in size 

 they moved downstream to the lower Bay where 

 salinities generally were greater than 10 o/oo. 

 In June 1971, for example, the average sizes of 

 fish were 72.5 mm in the lower Bay and 46.2 mm 

 in the upper Bay. The smalle.st juveniles were 

 found in the River. The fishes in the Bay aver- 

 aged from 3 mm larger in April to 45 mm larger in 

 August than those in the River. Collections by 

 seine indicated that larval and juvenile menhaden 

 also occurred inshore during the months they 

 were captured by channel net and trawl. Relative 

 abundance and sizes of young in these shallow 

 waters were similar to those of fishes caught at 

 comparable times offshore. 



Young, 31 to 50 mm TL, in April 1971 appeared 

 to attain a size of 91 to 120 mm by August (Table 

 3). They probably emigrated Gulfward in Sep- 

 tember since few fish over 90 mm were captured 

 that month. The small size of all catches after 

 August indicated that most juveniles had moved 

 out of the estuary (Table 2). The time of emigra- 

 tion of juveniles from estuarine waters agrees 

 with the results of Suttkus (1956) for Louisiana 

 but not with those of Springer and Woodburn 

 (1960), who indicated that movement from Tampa 

 Bay occurred in June or July. The bimodality of 

 lengths evident for June and for August in Table 

 3 indicates two spawning peaks, as did the larval 

 data for Pensacola Bay. 



Yearlings, hatched late in the 1969-70 spawn- 

 ing season, also appeared in East Bay and East 



Bay River from April (over 90 mm long) to Sep- 

 tember (over 150 mm long) in 1971 (Table 3). 

 In Table 3, size distributions were based on two 

 subsamples representing the largest catches in 

 the Bay and the River. 



SIGNIFICANT ASSOCIATES 



Anchovies may be the most important com- 

 petitors to menhaden for food and space in the 

 East Bay River area. The striped anchovy, 

 Anchoa hepsetus, and particularly the bay an- 

 chovy, A. mifchilli, were abundant in the bay at 

 the same time and at similar lengths as the Gulf 

 menhaden. In December, for example, 113 men- 

 haden, 24 to 32 mm, were collected in a seine 

 haul with 5,250 bay anchovy, 20 to 35 mm. Both 

 species form large schools, and anchovies and the 

 larval stage of menhaden feed by filtering zoo- 

 plankton. 



Various clupeids occurred with menhaden but 

 in numbers too small to suggest serious compe- 

 tition. Captured were 52 threadfin shad, Doro- 

 soma petenense, one skipjack herring, Alosa 

 chrysoch Ion's, and eight scaled sardines, Hare7i- 

 gnla penaacolae. 



The silver perch, Bairdiella chrysura, and prob- 

 ably many other species of fishes prey on young 

 menhaden in East Bay and East Bay River. In 

 the only stomach analysis of this study, 8 of 12 

 perch (152 to 199 mm) had 1 to 3 whole menhaden 

 (45 to 55 mm) in their stomachs. All the preda- 

 tors on menhaden found by Reid (1955), Cyno- 

 scion arenarius, Micropogon undidatus. Anus 

 felis, Bagre marinus, Flops saurits, and Synodus 

 foetens, were also found in our study area. 



SEASONAL OCCURRENCE 

 OF OTHER FISHES 



A summary of the number and size ranges of 

 species caught in this study is presented in 

 Table 4. Nomenclature and taxonomic arrange- 

 ment follow Bailey et al. (1970). Gulf menhaden 

 and bay anchovy made up approximately 92% 

 by number of all fish captured. Species not pre- 

 viously recorded from the Pensacola bays and 

 rivers are flat anchovy, Anchoviella perfasciata; 

 rough silversides, Membras marfinica; chain 

 pipefish, Syngnathus louisianae; and web burr- 

 fish, ChUomycterus antillarum. The only other 



