FISHERY BULLETIN: VOL. 84, NO. 1 



LOUISIANA 



Figure 6.— Movement of tagged juvenile brown shrimp from Caillou Lake, expressed as days at large before recap- 

 ture (from Gazey et al. 1982). Shrimp were released in June 1978. Regions of hypoxic bottom water, noted from June 

 to August, are overlaid onto this map (Fotheringham and Weissberg 1979; Bedinger et al. 1981; Comiskey and Farmer 

 1981). 



Table 1. — Louisiana brown shrimp catch data. 



'CPUE and catch data in 1973 and 1974 were significantly lower than that in 1972 (paired Mest, P < 0.05) 



portions of the shrimp life cycle implicate it as a prob- 

 able source of variation in annual shrimp yield. Sup- 

 port for this viewpoint has been documented in 

 laboratory experiments which indicate that brown 

 and white shrimp detect and avoid water with low 

 oxygen levels. 5 Brown shrimp were the least tolerant 



of the two species. They avoided dissolved oxygen 

 concentrations up to and including 2.0 ppm. White 

 shrimp did not avoid oxygen levels higher than 1.5 

 ppm. Variable behavior was exhibited by both species 

 at higher treatment levels. Total time (TT) spent in 

 water with 1.5 ppm did not differ between species, 



5 Renaud, M. 1985. Detection and avoidance of oxygen depleted 

 water by Penaeus setiferus and Penaeus aztecus. Unpubl. manuscr., 

 16 p. Southeast Fisheries Center Galveston Laboratory, National 



Marine Fisheries Service, NOAA, 4700 Avenue U, Galveston, TX 

 77550. 



24 



