374 



FISHERY BULLETIN OF THE FISH AND WILDLIFE SERVICE 



approaching nursery ground capacity should 

 not be discounted. 

 Upper Gulf Populations 



Pink shrimp play a comparatively minor role 

 in the penaeid species complex characteristic of 

 the northern Gulf coast. Only along the more 

 easterly reaches do they enter commercial catches 

 in any quantity, and then with very irregular 

 frequency. In some areas, especially in Texas, 

 pink shrimp are bought and sold as brown shrimp. 

 Such a practice masks the actual contribution 

 of this species to local fisheries, and at certain 

 seasons may seriously bias data of brown shrimp 

 landings as well. 



Condensed statistics of trawling efifort and 

 pink shrimp landings in the Apalachicola and 

 Pensacola-Mississippi River areas are given in 

 appendix tables 1, 3, and 5. Trace amounts of 

 pink shrimp taken in areas west of the Mississippi 

 River are also recorded in table 4. 



Commercial yield. — Yields of pink shrimp from 

 offshore waters in the Apalachicola and Pensa- 

 cola-Mississippi River areas averaged about 7 per- 

 cent of all shrimp taken annually in these areas 

 during the period 1956-59. Production in the 

 Apalachicola area fluctuated widely between a 

 maximum of 2.1 million pounds in 1958 and a 

 minimum the following year of only 11,000 pounds 

 (fig. 23). Landings originating in waters oflF 

 Alabama, Mississippi, and eastern Louisiana 

 collectively showed a steady decline from a 1956 

 high of about 0.8 million pounds. Production in 



£ COMMERCIAL VIELD tm.llions of pounds, heoi)*-on) 

 • -APALACHICOLA 

 o-PENSACOLA-MISSISSIPPi RIVER 



APALA- PENSACOLA. 

 CHICOLA MISS RIVER 



Figure 23. — Yield and biomass of pink shrimp populations 

 off the northeastern Gulf coast, 1956-59. 



both areas closely followed the seasonal patterns 

 typical of related species, reaching a maximum 

 during the spring or early summer. The largest 

 quantity of pink shrimp taken elsewhere off the 

 upper Gulf coast was 0.1 million pounds caught 

 off Texas in 1958. As noted earlier, this figure 

 (as well as landings of the same species in other 

 years) is too low due to misclassification of the 

 pink shrimp in the Texas coast area. 



Fishable biomass. — Limited data provide a 

 sketchy picture of offshore populations during 

 the 4-year study period. For the pink shrimp 

 population off Apalachicola, they indicate a 

 significant buildup in strength during 1956-58, 

 followed by a dramatic and inexplicable decline 

 in 1959 (fig. 23B). Peak abundance of small to 

 medium shrimp occurred annually during May- 

 July with especially large quantities available in 

 1957 and 1958. There is general similarity in 

 pink shrimp yield and population patterns be- 

 tween the Sanibel-Tortugas and Apalachicola areas 

 (cf. figs. 19 and 23), stinudating conjecture as to 

 population continuity in the eastern Gulf. 



As expected on the basis of low yield, biomass 

 indices reflected a correspondingly low level of 

 abundance for pink shrimp occupying the waters 

 between Pensacola and the mouth of the 

 Mississippi River (fig. 23B). Seasonal modes 

 occurred either slightly in advance of, or at about 

 the same time as those observed for the Apalachi- 

 cola area. Year-to-year variation in their magni- 

 tude was insignificant, there being no evidence of 

 a population trend during the 4 years of study. 

 Inshore population phases. — Even less note- 

 worthy than its offshore status was the pink 

 shrimp's status in adjacent inshore waters. Bays 

 and estuaries in the Apalachicola area yielded a 

 maximum of only 416,000 pounds in 1957, and 

 those in the Pensacola-Mississippi River area a 

 maximum of 196,000 pounds in the same year 

 (fig. 24A). Annual landings held fairly steady in 

 both areas with the exception of a sharp 1959 

 dropoff in the Apalachicola area. Pink shrimp in 

 catches from inshore waters were outweighed by 

 brown and white shrimp in almost every instance. 

 Inshore waters contributing to the northern Gulf's 

 commercial shrimp fisheries are shown in appendix 



table 5. 



The seasonal occurrence and relative density 

 of pink shrimp in inshore waters of the Apalachi- 

 cola and Pensacola-Mississippi River areas may 



