FISHERY BULLETIN: VOL. 87, NO. 2, 1989 



BROWN SHRIMP 



40 



O 30 



m MALES, TA N = 80 

  MALES, TX N = 181 



10-18 19-27 28-37 38-46 47-55 56- 

 RECAPTURE DEPTH (METERS) 



< 20 



O 



C 10 



PINK SHRIMP 



10-18 19-27 28-37 38-46 47-55 56-64 

 RECAPTURE DEPTH (METERS) 



< 40 

 O 



< 20 



Z 

 UJ 



o 



c 10 



□ FEMALES, TA N = 344 

  FEMALES, TX N = 480 



10-18 19-27 28-37 38-46 47-55 56-64 

 RECAPTURE DEPTH (METERS) 



0-9 10-18 19-27 28-37 38-46 47-55 56-64 

 RECAPTURE DEPTH (METERS) 



Figure 6.— Comparison of recapture depths of marked shrimp after release off Tamaulipas (TA) or Texas (TX). 



R/f Analysis 



Previous analyses indicated that sex had little to 

 do with components of shrimp movement (except 

 in some three-way interaction terms), so sexes were 

 pooled for R/f analysis. North versus south com- 

 parisons of cumulative R/f values after each brown 

 shrimp release (Table 8) indicated greater movement 

 toward the border after 5 of 10 Tamaulipas releases 

 and after 9 of 12 Texas releases. However, there 

 were no significant differences in north versus south 

 R/f values for brown shrimp in either state (Table 

 9). Comparisons of R/f values after pink shrimp re- 

 leases indicated greater movement toward the 

 border after 8 of 10 Tamaulipas releases and after 

 6 of 12 Texas releases (Table 8). Only pink shrimp 

 released off Tamaulipas exhibited significant north- 

 ward movement (Table 9). 



Replicate releases on different dates were made 

 at two sites off Tamaulipas and at all six sites off 



Texas (Table 8). The recapture patterns indicated 

 that shrimp collected near, and released on, a given 

 site did not always disperse in the same directions. 

 Only in 6 of 8 brown shrimp releases and 4 of 8 pink 

 shrimp releases were the paired R/f values higher 

 in the same directions. 



DISCUSSION 



Variation in components of movement was linked 

 to both species and release state. However, R/f 

 values indicated that during the study period recap- 

 tured brown shrimp exhibited no preferred move- 

 ment north or south off either Texas or Tamaulipas 

 while recaptured pink shrimp only showed signifi- 

 cant movement northward after Tamaulipas re- 

 leases. Thus, the 1986 Texas fishery did not lose 

 fishable biomass across the border as a result of the 

 Texas Closure and, in fact, may have gained biomass 

 due to the northward movement of pink shrimp off 



306 



