FINAL REPORT NOAA/NMFS GRANT NA16FM1658. SUBMITTED To:

Transcription

1 LIFE HISTORY, ESSENTIAL HABITAT AND STOCK ASSESSMENT OF HIGHLY MIGRATORY SHARKS IN U.S. AND MEXICAN WATERS: FISHERIES RESEARCH BY THE CENTER FOR SHARK RESEARCH, FINAL REPORT NOAA/NMFS GRANT NA16FM1658 SUBMITTED To: NOAAlNMFS Office of Sustainable Fisheries Highly Migratory Species Division 1315 East-West Highway Silver Spring, MD SUBMITTED By: Robert E. Hueter Center for Shark Research Mote Marine Laboratory APRIL 30, 2003 Mote Marine Laboratory Technical Report 913 This document is printed on recycled paper

2 TABLE OF CONTENTS EXECUTIVE SUMMARY PROJECT INFORMATION SUMMARY OF PROJECT ACCOMPLISHMENTS AND EXPENDITURES Work Accomplishments Primary Project Tasks Summary of Results Field research in MexicofTexas Florida offshore large shark surveys Archival tagging in South Carolina Small coastal shark assessment Florida coastal relative abundance surveys Tagging database Response to NMFS requests Publications and conferences Major Findings and Conclusions Expenditures SIGNATURE TABLES

3 EXECUTIVE SUMMARY Mote Marine Laboratory's Center for Shark Research (CSR) is an independent, international research center established by the U.S. Congress in 1991 and dedicated to the multidisciplinary study and public understanding of sharks, skates and rays. In , the CSR continued its mission to conduct scientific studies on sharks in cooperation with the National Marine Fisheries Service (NOAAlNMFS) to respond to the agency's need for biological data in order to manage shark fisheries. The primary emphasis of this research and information program involved biological assessments of sharks as a fishery resource. This project addressed major gaps in our resource information base for the blacktip shark (Carcharhinus limbatus), a common large coastal shark species inhabiting nearshore waters of the U.S. east coast, and other large and small coastal shark species. To assist NMFS in its objective to manage shark fisheries, the primary research activities undertaken by the CSR in this project were new studies on the life history, essential habitat, and population status of the blacktip shark and other large and small coastal sharks inhabiting state and federal waters of the Gulf of Mexico. This research was conducted primarily in the Gulf of Mexico off the U.S. coast (Florida and Texas), along the U.S. southeastern Atlantic coast (South Carolina) and along the Mexican Gulf coast. New technology in the form of archival and satellite tags were deployed on large sharks of the region. The work in Mexico was conducted in collaboration with the Instituto Nacional de la Pesca (INP) as part of the MEXUS-Gulf initiative. The CSR also served as a center for the public understanding and communication of information on sharks and for national and international exchanges on issues relating to shark biology. Through these various activities the CSR significantly advanced the course of shark research and fisheries conservation and management in , and continued to serve as a prod uctive partnership between Mote Marine Laboratory and the National Marine Fisheries Service.

4 PROJECT INFORMATION Award Number: NA16FM1658 Amount of Award: Federal $ 179,000 Applicant Match $ 0 Total $ 179,000 Project Title: Life History, Essential Habitat and Stock Assessment of Highly Migratory Sharks in U.S. and Mexican Waters: Fisheries Research by the Center for Shark Research, Recipient: Mote Marine Laboratory, Sarasota, Florida Award Period: July 1, 2001 to June 30, 2002 Period Covered by this Report: July 1, 2001 to June 30, 2002 (Final Report) 2

5 SUMMARY OF PROJECT ACCOMPLISHMENTS AND EXPENDITURES Work Accomplishments Primary Project Tasks: The following primary tasks were scheduled for this project: a. Field research in MexicolTexas b. Florida offshore large shark surveys c. Archival tagging in South Carolina d. Small coastal shark assessment e. Florida coastal relative abundance surveys f. Tagging database g. Response to NMFS requests h. Publications and conferences Summary of Results: a. Field research in MexicolTexas Collaborative research with Mexico's Instituto Nacional de la Pesca (INP) was conducted during the project year. INP scientists in Quintana Roo provided historical information on shark surveys in Laguna Yalahau, where CSR scientists have been collecting and tagging sharks since Information on. tag returns was collected and plans were made for additional field studies to complement the previous work in the region. Due to factors such as deterioration in the linkage between the INP and NMFS through the MEXUS program, as well as changes in leadership in Mexico, the CSR has begun to experience difficulties in obtaining permits to conduct field research in Mexico. To counteract this, efforts were made to enhance the reporting of tag recaptures from within Mexico by improving the link between the CSR and INP staff that regularlyvisitfishing areas and interact with fishermen directly. Collaborative shark tagging efforts between the CSR and Texas recreational anglers were conducted during the project year. Young blacktip sharks (Carcharhinus limbatus) in their Texas nurseries and other juvenile and small adult sharks in the western Gulf have been targeted to assess the exchange rate of this species between U.S. and Mexican coastal waters. A total of 71 sharks of 6 species were tagged and released including 43 young blacktip sharks, the target species for this work. Fin clips were taken from 31 of these blacktips to aid in an ongoing population genetics study of this species through a collaboration with geneticists at Southern Illinois University. Four blacktip sharks tagged in Texas with CSR tags were recaptured during this period. One of these sharks was recaptured during the fall at the south tip of Texas (south end of Padre Island), about 85 nautical miles south of its tagging site near Corpus Christi. 3

6 b. Florida offshore large shark surveys Sampling for large coastal sharks (blacktip; bull, C. leucas; great hammerhead, Sphyrna mokarran; and others) was conducted throughout the project year in two primary areas off Florida (Tables 3-4): 1) southwest Florida in the vicinity of Boca Grande Pass, where these sharks congregate in the late spring and summer; and 2) the Florida Keys in the vicinity of Summerland Key, about 20 miles from Key West, where these sharks are found in the late fall and winter. Sharks were caught on longlines or drumlines, tagged with external tags, and released. A total of 241 sharks of nine species were caught and 207 were tagged and released. Of these tagged sharks, 20 were additionally fitted with either satellite or acoustic tags. Some sharks were outfitted with satellite tags (pop-off archival tags [PAT] or satellite position-only tags [SPOT]). Other sharks were outfitted with acoustic telemetry transmitters and tracked for short periods (up to six hours). This exploratory research forms the basis for extended studies on the stock structure and essential habitat of these coastal species. Offshore sampling was undertaken aboard the RN Eugenie Clark in May and June (Tables 5-6). Fourteen sets of 10 drumlines each were undertaken in May in the eastern Gulf of Mexico between Tampa Bay and Captiva Island. Twenty-nine sharks of seven species were caught and 22 were tagged and released. Live sharks were measured, tagged, had a genetic sample collected and release. Five dead animals were retained, one of which was sampled for studies of yolk proteins. One sandbar shark (C. plumbeus) was fitted with a PAT tag to study its movement patterns. A single large set (20 hooks) was undertaken in June to collect blacktip sharks. This set caught 16 sharks, 10 of them blacktips. Data collected during these sets are being used to examine bait effectiveness and compare inshore and offshore catch rates over the next decade to monitor results and effectiveness of state and federal FMP's for shark fisheries. c. Archival tagging in South Carolina Daily sampling for blacktip sharks off Cape Romain, South Carolina, was conducted in June A floating longline with 20 hooks was used, and the line was patrolled and checked continuously during the fishing period. The hooks were rebaited as needed. A total of 60 sharks were caught, including twelve large adult blacktip females. Of these eleven were alive on the line. One was found dead on the line after a bull shark broke the line, causing a retrieval delay. Of the eleven live sharks, nine were successfully tagged with both archival and M-type tags (Table 7). All released sharks swam vigorously away after tagging and release. Other species encountered were Atlantic sharpnose, bull, lemon (Negaprion brevirostris) and bonnethead sharks.,~ d. Small coastal shark assessment The current status of four species of small coastal sharks [Atlantic sharpnose (Rhizoprionodon terraenovae), blacknose (C. acronotus), finetooth (C. isodon) and bonnethead (Sphyrna tiburo)] was assessed using Bayesian age-structured population models. The results of the model indicated that the best estimate of the status of Atlantic 4

7 sharpnose shark in 2000 was 69.6% of the 1972 biomass. Sensitivity tests indicated that changes in data on catches, catch rates and biology did not significantly change the estimates of biomass. The results of risk assessment indicate that the probability of depletion of the population to below 5% of the 1972 level is low, even with substantial increases in future catches. Model results for the other three species indicate that mature female biomass levels (relative to 1972) were 94.1 %, 9.1 % and 79.7%, for the blacknose, finetooth and bonnethead, respectively. The data used to construct these models was of lower quality than for the Atlantic sharpnose, and the results are highly uncertain. The high level of depletion estimated forthe finetooth shark appears invalid due to conflicting natural mortality and reproductive data. The results for all species show a high level of uncertainty, indicating a need to improve the quality of data collected if assessments are to be improved. Figure 1: Biomass depletion estimates of Atlantic sharpnose sharks in the Gulf of Mexico and Atlantic. Dashed lines are 90% confidence intervals; solid lines are median values <l> 80 > " <l> N r-- en 60 -., ~ "--' (f) (f) (ti E 0 co Year e. Florida coastal relative abundance surveys Field trips to two shark nursery areas in the Florida Gulf (Pine Island Sound and Yankeetown) were conducted during the project year to assess the relative abundar1ce of blacktip shark neonates, young-of-the-year (YaY) and older juveniles (Tables 8-11). These field trips comprised 100 gillnet sets (50 in each area) using a standardized, randomstratified design, the identical methodology used during previous CSR studies in these same areas, resulting in the capture of 1,502 sharks of 7 species including 738 blacktips. Of these captured sharks, 857 were tagged and released using conventional dart tags designed for small sharks. Additionally, 143 fin clip samples were collected from neonate and yay blacktip sharks during these surveys as part of an ongoing population-level 5

8 genetics study of this species with geneticists at Southern Illinois University. All bycatch was identified, measured, and released. A total of 652 specimens were captured comprising 29 species. f Tagging database The CSR shark tagging database was maintained and updated throughout the project year as new tagging was conducted and recaptured tags were reported. Efforts were also made to improve the information structure of some of the data tables in order to make the querying process more efficient. Preliminary analyses of the most recent relative abundance data were initiated and compared to other years data in orderto detect changes in juvenile blacktip shark abundance and gauge the rebuilding of this stock. Additionally, a total of 63 recaptures were reported and incorporated into the database for later analysis (Table 12). One great hammerhead shark (Sphyrna mokarran) tagged in the Florida Keys was recaptured by a commercial fisherman in the Atlantic (off Port Salerno) after being at large for 3 days. This represents a minimum movement of 198 nautical miles. Tag rewards were paid to fishermen for recovery of dart, roto, M-type and for one PAT satellite tag that had prematurely separated from a large blacktip shark. Effort was made to improve satellite tag attachment techniques during the period of this report. Part of these efforts consisted of attaching a "dummy" PAT tag to a large bull shark in the lab's public aquarium and observing how the tag and shark responded to biofouling and other associated stresses. g. Response to NMFS Needs A full report on all CSR data on shark nursery areas collected over the past ten years was prepared for submission to the NMFS Narragansett Laboratory in early During July and August 2001, the CSR was inundated with requests for information on sharks in response to the summer's media focus on shark attack. Numerous media interviews were given by CSR scientists and much of the substance of these interviews involved questions of shark fisheries management. Information on shark migratory patterns and attack behavior was provided to NMFS on an as-needed basis during this unusual period. CSR Director Dr. Robert Hueter made a special presentation to the staff of NMFS/SERO in October 2001 on CSR research and related information. In April 2002, Dr. Hueter participated in the annual meeting of the Highly Migratory Species Advisory Panel at NMFS headquarters in Silver Spring in April. Information was provided on the status of shark stocks along the U.S. east coast. Also in April, Dr. Hueter participated in a NMFS workshop in Tampa on Southeast Region Cooperative Research. In May, Dr. Hueter participated in a NMFS-sponsored effort in Washington DC to inform the national media on issues related to shark attack, with a press conference at the National Press Club and corollary activities. Dr. Hueter and Staff Scientist Dr. Colin Simpfendorfer also participated in the 2002 Shark Stock Evaluation Workshop (SEW) at the NMFS Laboratory in Panama City in June. Six CSR documents were prepared and submitted to the SEW that were used in the data presentations and analyses for the workshop. 6

9 h. Publications and Conferences CSR researchers participated in a number of scientific conferences during this project year, including the American Society of Ichthyologists and Herpetologists & American Elasmobranch Society annual meetings in State College, Pennsylvania (July 2001) and Kansas City, Missouri (June 2002), the American Fisheries Society annual meeting in Phoenix, Arizona (August 2001), the 1 51 International Elasmobranch Husbandry Symposium in Orlando, Florida (October 2001), and a NMFS-sponsored conference on shark attack in Tampa, FL (June 2002). Scientific presentations in shark biology were made at all of these meetings by CSR staff. Results of CSR research also were reported through scientific publications during the project. Among the more than 40 publications produced by the CSR scientific staff during the project year were the following (CSR staff in bold): Hueter, RE. and C.A. Simpfendorfer (2002) Trends in blue shark abundance in the western North Atlantic as determined by a fishery-independent survey. ill Sharks of the Open Ocean (in press). Wilga, C.D., R.E. Hueter, P.C. Wainwright and P.J. Motta (2002) Evolution of upper jaw protrusion mechanisms in elasmobranchs. American Zoologist (in press). Pretlow-Edmonds, M.A., P.J. Motta and R.E. Hueter (2001) Food capture kinematics of the suction feeding horn shark, Heterodontus francisci. Environmental Biology of Fishes 62: C. Manire, R. Hueter, E. Hull and R Spieler (2001) Serological changes associated with gill-net capture and restraint in three species of sharks. Transactions of the American Fisheries Society 130: Hueter, R.E., C.J. Murphy, M. Howland, J.G. Sivak, J.R Paul-Murphy and H.C. Howland (2001) Dynamic refractive state and accommodation in the eyes of free-swimming vs. restrained juvenile lemon sharks (Negaprion brevirostris). Vision Research 41: Hueter, R.E. (2001) Historical perspectives: Perry W. Gilbert. Copeia 2001 (1 ): Heupel, M.R. and R.E. Hueter (2002) Importance of prey density in relation to the movement patterns of juvenile blacktip sharks (Carcharhinus Iimbatus) within a coastal nursery area. Marine and Freshwater Research 53 : Hueter, R.E., M.R. Heupel, E.J. Heist and 0.8. Keeney (2002) The implications of philopatry in sharks for the management of shark fisheries. NW Atl. Fisheries Org. Research Document SCR Doc. 02/122:1-9. Hueter, R.E., M.R. Heupel, E.J. Heist and 0.8. Keeney (In review) The implications of philopatry in sharks for the management of shark fisheries. Journal of Northwest Atlantic Fishery Science. Motta, P.J., R.E. Hueter, T.C. Tricas and AP. Summers (2002) Kinematic analysis of suction feeding in the nurse shark, Ginglymostoma cirratum (Orectolobiformes, Ginglymostomatidae). Copeia 2002: Sasko, D.E., R.E. Hueter and P.J. Motta (In review) Prey capture behavior and kinematics of the Atlantic cownose ray, Rhinoptera bonasus. Copeia. Simpfendorfer, C.A., M.R. Heupel and R.E. Hueter (2002) Estimation of short-term centers of activity from an array of omnidirectional hydrophones and its use in studying animal movements. Canadian Journal of Fisheries and Aquatic Sciences 59 :

10 Simpfendorfer, C.A., R.E. Hueter, U. Bergman and S.M.H. Connett (2002) Results of a fishery-independent survey for pelagic sharks in the western North Atlantic, Fisheries Research 55: Simpfendorfer, CA, Kitchingman, AM, and McAuley, RB Distribution, biology and fishery importance of the pencil shark, Hypogaleus hyugaensis (Elasmobranchii: Triakidae), in the waters off south-western Australia. Marine and Freshwater Research 53: Simpfendorfer, CA, McAuley, RB, Chidlow J, and Unsworth, P Age and growth of the dusky shark, Carcharhinus obscurus, from Western Australian waters. Marine and Freshwater Research 53: Heupel, MR and Simpfendorfer, CA Estimation of survival and mortality of juvenile blacktip sharks, Carcharhinus limbatus, within a nursery area based on telemetry data. Canadian Journal of Fisheries and Aquatic Sciences 59: Simpfendorfer, CA Smalltooth sawfish: the USA's first endangered elasmobranch? Endangered Species Update, 19: Heupel, MR and Simpfendorfer, CA. Submitted. Intra-specific interactions between juvenile sharks within a nursery area. Marine Biology. Simpfendorfer, CA, Goodreid, AB, and McAuley, RB Size, sex and geographic v!3riation in the diet of the tiger shark (Galeocerdo cuvier) in Western Australian waters. Environmental BioI. of Fishes, 61 : Simpfendorfer, CA, Goodreid, A, and McAuley, RB The diet of three commercial important sharks from Western Australian waters. Marine and Freshwater Research, 52 : M.R. Heupel & R.E Hueter (2001). Use of an automated acoustic telemetry system to passively track juvenile blacktip shark movements. In: Electronic Tagging and Tracking in Marine Fisheries J.R. Sibert & J.L. Nielsen (eds.) pp Kluwer Academic Publishers, Netherlands. C.A. Simpfendorfer, M.R. Heupel & R.E. Hueter (2002). Estimation of short-term centers of activity from an array of omnidirectional hydrophones, and its use in studying animal movements. Canadian Journal of Fisheries and Aquatic Sciences 59, M.R. Heupel, C.A. Simpfendorfer & R.E. Hueter (In review). E.stimation of shark home ranges using passive monitoring techniques. Environmental Biology of Fishes. Heithau5, M. R, L. M. Dill, G. J. Marshall, and B. Buhleier Habitat use and foraging behavior of tiger sharks (Galeocerdo cuvier) in a seagrass ecosystem. Marine Biology 140: Heithau5, M. R. and A. Frid Species and sex-class differences in shark-inflicted injury frequencies, escape ability, and habitat use of green and loggerhead turtles. Marine Biology 140: Heithau5, M. R. and L. M. Dill Feeding Tactics and Strategies. Pages in Perrin, W. F., B. Wursig, and H. G. M. Thewissen (eds.). The Encyclopedia of Marine Mammals. Academic Press.. of. Heithau5, M. R. and L. M. Dill Food availability and tiger shark predation risk influence bottlenose dolphin habitat use. Ecology 83: Dill, L. M., M. R. Heithau5, and C. J. Walters. in press. Behaviorally-mediated indirect species interactions in marine communities and their importance to conservation and management. Ecology. Heithau5, M. R. in review. Fish communities of seagrass meadows and associated habitats in Shark Bay, Western Australia. Bulletin of Marine Science. 8

11 Heithau5, M. R. in review. A trade-off between prey abundance and predation risk influence habitat use by a marine bird. Marine Biology. Heithau5, M. R. and A. Frid. in review. Optimal diving under the risk of predation. Journal of Theoretical Biology. Frid, A., M. R. Heithau5, and L. M. Dil l. in review. Sea turtles modify diving behavior in response to tiger shark predation risk. Animal Behavior. Major Findings and Conclusions: 1) Our studies of the blacktip shark nursery in Laguna Yalahau, Quintana Roo, Mexico have revealed that this area is a primary nursery for the species, fishing pressure on these juvenile sharks is extremely high in local Mexican waters, CPUE of the young blacktips in the lagoon has remained relatively stable since 1995, and migration patterns indicate a generally westerly movement out of the lagoon. No evidence of movements into the Caribbean or the U.S. eastern Gulf of Mexico has been found. 2) Young blacktip sharks in the western Gulf of Mexico comprise a different population from the eastern Gulf (both U.S. and Mexican) as revealed through both tagging studies and genetic analyses. 3) New fishery-independent surveys by the CSR in the Florida Gulf have been established to build an historical record of CPUE of large sharks in coastal and offshore waters. Satellite tag technology has been deployed to track long-term movements of large sharks in these waters and archival tags have been deployed in large blacktip sharks off South Carolina to track their movements. 4) Best estimate of the status of the Atlantic sharpnose shark in 2000 is 69.6% of the 1972 biomass and the probability of depletion of the population to below 5% of the 1972 level is low, even with substantial increases in future catches. Model results for the other small coastal shark species indicate that mature female biomass levels (relative to 1972) were 94.1 %, 9.1 % and 79.7%, for the blacknose, finetooth and bonnethead, respectively. The data used to construct these models was of lower quality than for the Atlantic sharpnose, and the results are highly uncertain. 5) Through its shark-tagging database, providing of data to NMFS for various management and public information needs, and participation of CSR scientists in,..: numerous scientific conferences as well as the publication of over 40 scientific papers, the Mote Center for Shark Research continued in a leading role of conducting excellent scientific research on sharks to improve our understanding of their role as a valuable marine resource. 9

12 Expenditures A total of $179,000 in project costs was scheduled for this one-year project. Actual expenditures during the project were $198,690. The project cost overrun of $19,690 was absorbed by Mote Marine Laboratory internal (nonfederal) programmatic funding as an applicant match to the project. SIGNATURE 30 April 2003 Robert E. Hueter, Ph.D. Principal Investigator Director, Center for Shark Research Mote Marine Laboratory Date 10

13 Table 1. location data for Texas recreational angler-tagged sharks during the period of this report. Sample Month Day Year Gear location latitude longitude Depth # (ft.) RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR FP-Surfside Beach, Access 7 29'03.43N 95'08.55W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Matagorda-Matagorda Beach 28'40.50N 95'49.80W RR Matagorda-Matagorda Beach 28'40.50N 95'49.80W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Matagorda-East Matagorda Beach 28'39.62N 95'49.36W RR Matagorda-East Matagorda Beach 28'39.09N 95'50.51W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86N 97'12.98W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86 N 97'12.98 W RR Corpus Christi-Bob Hall Pier, Padre Is. 27'34.86 N 97'12.98 W RR Corpus Christi-PINS 27'10.49 N 97'22.14 W RR Matagorda-10 mile marker, Matagorda 28'55.00 N 96'20.00W RR Matagorda-8 mile marker, Matagorda 28'50.00 N 96'25.00W RR Matagorda-8 mile marker, Matagorda 28'50.00 N 96'25.00W RR Corpus Christi-40 mile marker, PINS RR Corpus Christi-Bob Hall Pier, Padre Is N 97'12.98 W 15 Table 2. Sharks caught, tagged and released in Texas coastal waters during the period of this report (n=71) Sample # Gear Scientific Name Sex Repro. PCl Fl Tl STl Tag # Condition (cm) (cm) (cm) (cm) 98.0 RR Carcharhinus limbatus M RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Sphyma lewini F RR Sphyma lewini F RR Sphyrna lewini F

14 101.0 RR Sphyma lewini F RR Sphyma lewini F RR Sphyma lewini M RR Carcharhinus brevipinna F RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Sphyma lewini F RR Carcharhinus limbatus F RR Sphyma lewini M RR Carcharhinus limbatus M RR Carcharhinus limbatus M RR Carcharhinus isodon F RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus brevipinna F RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus limbatus M RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus isodon F RR Carcharhinus isodon M RR Carcharhinus leucas M RR Carcharhinus limbatus F RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus M RR Carcharhinus isodon M RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus limbatus M RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus isodon M RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus isodon F RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus isodon M RR Carcharhinus isodon F RR Carcharhinus isodon F RR Carcharhinus leucas M RR Carcharhinus isodon F RR Carcharhinus isodon F RR Carcharhinus isodon F RR Carcharhinus plumbeus M RR Carcharhinus plumbeus F RR Carcharhinus limbatus F ~ RR Carcharhinus leucas M RR Carcharhinus limbatus M RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus limbatus F RR Carcharhinus brevipinna M RR Carcharhinus limbatus F

15 Table 3. Offshore sampling efforts for large sharks in Boca Grande and Florida Keys. Sample # Month Day Year Gear Location Latitude Longitude Depth (ft.) DL C 1-Boca Grande Pass 26' N 82' W DL C7-Charlotte Harbor 26' N 82'17.646W DL C1-Boca Grande Pass 26'42.302N 82'16.108W DL C1-Boca Grande Pass 26'42.353N 82'16.03W DL C1-Boca Grande Pass 26'42.383N 82'15.974W DL C1-Boca Grande Pass 26'42.462N 82'15.869W DL C1-Boca Grande Pass DL C1-Boca Grande Pass 26'42.533N 82' W DL C1-Boca Grande Pass 26'42.447N 82' W DL C1-Boca Grande Pass 26'42.324N 82'16.07W DL C1-Boca Grande Pass 26'42.304N 82'16.211W DL C1-Boca Grande Pass 26'42.06N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1 -Boca Grande Pass 26'42.06N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'42N 82' W DL C1-Boca Grande Pass 26'41.97N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C 1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'42.18N 82' W DL C1-Boca Grande Pass 26'42.168N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1 -Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'42.42N 82' W DL C 1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'42.078N 82' W DL C1-Boca Grande Pass 26'42.078N 82' W DL C1-Boca Grande Pass 26'42.078N 82' W DL C 1-Boca Grande Pass 26'42.078N 82' W DL C 1-Boca Grande Pass 26' N 82' W DL C1 -Boca Grande Pass 26'42.258N 82' W DL C 1-Boca Grande Pass 26'42.42N 82 ' W DL C 1-Boca Grande Pass 26'42.42N 82' W DL C1 -Boca Grande Pass 26'42.42N 82' W DL C1-Boca Grande Pass 26'41.604N 82' W DL C1-Boca Grande Pass 26'41.604N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'41.982N 82' W DL C1-Boca Grande Pass 26'41.982N 82' W DL C1-Boca Grande Pass 26'41.982N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'42.252N 82' W DL C1-Boca Grande Pass 26'42.45N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W ~ DL C1-Boca Grande Pass 26'42.426N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1 -Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C 1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C 1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL C1 -Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26'42.36N 82' W 24 13

16 DL C1-Boca Grande Pass 26' N 82' W DL C1-Boca Grande Pass 26' N 82' W DL Keys-Nr Tarpon Belly Key 24' N 81 ' W DL Keys-Nr Tarpon Belly Key 24' N 81' W DL Keys-Nr Tarpon Belly Key 24' N 81 ' W DL Keys-N of Sawyer Key - channel 24' N 81 ' W DL Keys-N of Sawyer Key - channel 24'45.72N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Racoon Key 24'44.358N 81 ' W DL Keys-American Shoal - coral/sg shoal 24' N 81 ' W DL Keys-Carol's Reef - edge 24'33.267N 81 ' W DL Keys-Carol's Reef - edge 24'33.141N 81 ' W DL Keys-Carol's Reef - edge 24' N 81' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81' W DL Keys-Bahia Honda-Bay Side-bridge 24' N 81' W DL Keys-Bahia Honda-Bay Side-brige 24'39.678N 81 ' W DL Keys-Bahia Honda-Bay Side-bridge 24' N 81' W DL Keys-Bahia Honda-Bay Side-bridge 24' N 81' W DL Keys-Bahia Honda-Ocean Side-bridge 24' N 81' W DL Keys-Bahia Honda-Ocean Side - bridge 24' N 81' W DL Keys-Bahia Honda-Bay Side -bridge 24'39.774N 81' W DL Keys-Bahia Honda-Mid&Ocean Side 24' N 81' W DL Keys-Bahia Honda-Mid&Ocean Side 24' N 81 '17.133W DL Keys-Bahia Honda - Btwn bridges 24' N 81'17.028W DL Keys-Newfound Harbour 24'36.414N 81' W DL Keys-Newfound Harbour 24' N 81 ' W DL Keys-Bunson Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24'44.286N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Gulf - off Riding 24' N 81 ' W DL Keys-Gulf - off Riding 24'47.223N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81 ' W DL Keys-Tarpon Belly Key 24' N 81' W DL Keys-Gunbar Wreck - on Sea Boots DL Keys-Gunbar Wreck - on Sea Boots DL Keys-Gunbar Wreck - on Sea Boots DL Keys-Gunbar Wreck - on Sea Boots 24' N 81 ' W DL Keys-Gunbar Wreck - on Sea Boots 24' N 81 ' W DL Keys-Bahia Honda Bridge-between them 24' N 81 ' W DL Keys-Newfound Harbour 24'36.144N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81 '22.527W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Bahia Honda Bridge-Gulf side 24'39.741N 81 ' W DL Keys-Bahia Honda Bridge-Gulf side 24' N 81' W DL Keys-Bahia Honda Bridge-Gulf side 24'39.708N 81' W DL Keys-Bahia Honda Bridge-btwn brgs 24' N 81 ' W DL Keys-Bahia Honda Bridge-outside 24' N 81 ' W 25 ~ ~ 14

17 DL Keys-Carel's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carel's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carel's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carel's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carel's Reef 24' N 81' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24'33.366N 81 ' W DL Keys-Carel's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24'33.165N 81' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24'31.812N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81'9.4314W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81' W DL Keys-Marquesa's South 24' N 81 ' W DL Keys-Marquesa's South 24' N 81 ' W,4> DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carel's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81 ' W DL Keys-Carol's Reef 24' N 81' W DL Keys-Carol's Reef 24'19.821N 81' W DL Keys-Carel's Reef 24' N 81' W DL Keys-Carel's Reef - Patch Reef 24'33.366N 81 ' W 21 15

18 DL Keys-Carol's Reef - Patch Reef 24' N 81 ' W DL Keys-Carol's Reef - Patch Reef 24' N 81 ' W DL Keys-Carol's Reef - Patch Reef 24' N 81 ' W DL Keys-Carol's Reef - Patch Reef 24' N 81 ' W DL Keys-Carol's Reef - Patch Reef 24' N 81 ' W DL Keys-Carol's Reef - Patch Reef 24' N 81 ' W DL Keys-Carol's Reef - Patch Reef 24' N 81' W DL Keys-Carol's Reef - Patch Reef 24' N 81' W DL Keys-Carol's Reef - Patch Reef 24' N 81' W DL Keys-Bahia Honda - bridge 24'39.579N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Bahia Honda - bridge 24' N 81 ' W DL Keys-Tarpon Belly - channel 24' N 81'32.235W DL Keys-Tarpon Belly - channel 24' N 81 ' W DL Keys-Tarpon Belly - channel 24' N 81 ' W DL Keys-Tarpon Belly - channel 24' N 81' W DL Keys-Tarpon Belly - channel 24' N 81 ' W DL Keys-Tarpon Belly - channel 24' N 81'32.106W DL Keys-Rock Humps 24' N 82'14.589W DL Keys-Northwest Marquesas - flats 24'36.651N 82' W DL Keys-Northstar Wreck 24'31.632N 82' W DL Keys-Northwest Marquesas - flats 24' N 82' W DL Keys-Northstar Wreck 24' N 82' W DL Keys-Patricia Wreck 24' N 82' W DL Keys-Patricia Wreck 24' N 82' W DL Keys-Northstar Wreck 24' N 82' W DL Keys-Northstar Wreck 24'31.632N 82' W DL Keys-Northwest Marquesas - flats 24' N 82' W DL C1-Boca Grande Pass 26'42.534N 82'15.418W DL C1-Boca Grande Pass 26'42.612N 82'15.218W DL C1-Boca Grande Pass 26'42.632N 82'14.745W DL C1-Boca Grande Pass 26'43.077N 82' W DL C1-Boca Grande Pass 26'42.832N 82'14.266W DL C1-Boca Grande Pass 26'42.480N 82' W DL C1-Boca Grande Pass 26'42.487N 82' W DL C1-Boca Grande Pass 26'42.446N 82'1 5814W DL C1-Boca Grande Pass 26'42.645N 82' W DL C1-Boca Grande Pass 26'42.652N 82'15.151W DL C1-Boca Grande Pass 26'42.381N 82'15.909W DL C1-Boca Grande Pass 26'42.478N 82' W DL C1 -Boca Grande Pass 26'42.575N 82'15.344W DL C1-Boca Grande Pass 26'42.602N 82'15.314W 25 Table 4. Sharks captured in fishery-independent offshore sampling in the Keys and Boca Grande. Sample Scientific Name Sex PCl Fl Tl STl Tag Electronic Tag Conaition # (cm) (cm) (cm) (cm) Number(s) Ginglymostoma eiffatum M R Careharhinus aeronotus F R Ginglymostoma eiffatum F Ginglymostoma ciffatum F Carcharhinus leueas F J Sphyma mokaffan F R0250 I R Careharhinus aeronotus F R Carcharhinus Iimbatus F J1177 Transmitter # Carcharhinus aero notus F R0282 I R