248 



Fishery Bulletin 94(2). 1996 



gered Species Act, Section 7 Consultation, Biological 

 Opinion, NMFS, 14 November 1994; Mitchell 4 ). As a 

 consequence, NMFS developed an Emergency Re- 

 sponse Plan (Federal Register, vol. 60, no. 77, p. 

 19885-19886, 21 April 1995; Federal Register, vol. 

 60, no. 85, p. 21741-21745, 3 May 1995). This plan, 

 a resurgence of sea turtle strandings along the Texas 

 coast during the spring 1995 shrimping season 

 (Shaver, 1995), and an ensuing ruling by Judge 

 Samuel B. Kent (Center for Marine Conservation us. 

 Brown, C.V. No. G-94-660, U.S. District Court, 

 Galveston, Texas) led to additional TED restrictions 

 on shrimping seaward to 12 nautical miles. 



There is little evidence to support hypothesis 5, 

 that causes of strandings other than incidental cap- 

 ture of sea turtles in shrimp trawls were in synchrony 

 with shrimping. It seems unlikely that a major 

 nonshrimping cause of sea turtle mortality has es- 

 caped detection during the many years of study of 

 factors causing sea turtle injury and mortality at sea 

 (National Research Council, 1990; Kemp's Ridley 

 Recovery Team 7 ). Prior to our analyses, we deleted 

 stranding records that represented known or likely 

 causes (Table 1), even when some of these causes did 

 not absolutely rule out incidental capture in shrimp 

 trawls (Table 1). The records retained for analysis 

 represented strandings for which no cause was 

 known. Nevertheless, it is possible that causes other 

 than shrimping contributed to the unexplained 

 strandings that were retained for our analyses, be- 

 cause it is known that there are other minor causes 

 of sea turtle mortality, some of which could have been 

 in synchrony with shrimping. 



The lower total number of strandings in the north- 

 western Gulf in 1990-93 as compared with 1986-89 

 (Tables 9 and 10) would be encouraging were it not 

 for differences in STSSN coverage in 1990-93 and 

 1986-89. Schroeder ( 1989), Whistler ( 1989), and the 

 National Research Council (1990) pointed out that 

 temporal-spatial coverage of sea turtle strandings 

 is rarely uniform because the STSSN depends for the 

 most part on volunteers. During 1986-89, to supple- 

 ment the efforts of volunteers, universities, and other 

 agencies (Texas A&M University, the University of 

 Texas, National Park Service, U.S. Fish and Wildlife 

 Service, and Texas Parks and Wildlife Department), 

 NMFS Galveston Laboratory personnel conducted 

 systematic surveys at least once a month along ac- 

 cessible shorelines of beaches bordering the Gulf from 



' Kemp's Ridley Recovery Team. 1992. Recovery plan for the 

 Kemp's ridley sea turtle iLepidochelys kempii). Prepared for 

 the Southwest Region, U.S. Fish and Wildlife Service. Albu- 

 querque, New Mexico, and National Marine Fisheries Service, 

 Washington. DC, 40 p. 



the Mermentau River to the Rio Grande (Caillouet 

 et al., 1991 ). During 1990-93, personnel at Galveston 

 Laboratory focused their coverage only on subarea 

 18 during March-November; STSSN coverage in 

 other areas of the northwestern Gulf in those years 

 depended more on volunteers, universities, and other 

 agencies than was the case in 1986-89. Therefore, 

 the decrease in total number of strandings might 

 have occurred because of a reduction in STSSN cov- 

 erage, but the mandatory use of TED's and the de- 

 crease in total shrimp fishing effort, both on the up- 

 per and lower coasts (Table 2), cannot be ignored as 

 possible contributing factors. The statistical associa- 

 tion between stranding rates and fishing intensities 

 persisted in 1990-93 despite the reduction in total 

 strandings. It is essential that STSSN coverage of 

 strandings be consistent, both spatially and tempo- 

 rally, to provide data sufficient to assess real trends 

 in sea turtle strandings and to determine their rela- 

 tionship to natural as well as anthropogenic causes. 

 The statistical association between sea turtle 

 stranding rates and shrimp fishing intensities in the 

 northwestern Gulf is worthy of concern and further 

 attention. Continued strandings of sea turtles dem- 

 onstrate that the problem of sea turtle mortality at 

 sea has not been solved (Henwood et al., 1992; 

 Shaver, 1994, 1995). It is clear that further efforts 

 will be necessary to solve this problem and thereby 

 speed the recovery of sea turtle populations. Those 

 efforts must include reduction or elimination of hu- 

 man-caused sea turtle mortality at sea (National 

 Research Council, 1990; Henwood et al., 1992). 



Acknowledgments 



Special thanks are due to all who documented sea 

 turtle strandings in the northwestern Gulf during 

 1986-93, and especially the National Biological Ser- 

 vice, U.S. Dept. of Interior, Corpus Christi, Texas, 

 and the Aquarium of the Americas, New Orleans, 

 Louisiana, for coordinating the collection and pro- 

 cessing of stranding data. We greatly appreciated 

 comments and suggestions by Jeffrey Brown, Clark 

 Fontaine, William Jackson, John Mitchell, Charles 

 Oravetz, Erich Stabenau, and anonymous reviewers 

 of the manuscript. 



Literature cited 



Caillouet, C. W., Jr., M. J. Duronslet, A. M. Landry Jr., 

 D. B. Revera, D. J. Shaver, K. M. Stanley, R. W. Heinly, 

 and E. K. Stabenau. 



1991. Sea turtle strandings and shrimp fishing effort in the 



