CENTER FOR SHARK RESEARCH (CSR) AT MOTE MARINE LABORATORY

FINAL REPORT NOAA/NMFS Project NA27FL0142

Submitted to: NOAA/NMFS Southeast Regional Office 9721 Executive Center Drive St. Petersburg, FL 33702

Submitted by: Mote Marine Laboratory 1600 Ken Thompson Parkway Sarasota, FL 34236

Robert E. Hueter, Ph.D. Director, MML Center for Shark Research

MOTE MARINE LABORATORY TECHNICAL REPORT NO. 402 h

December 20, 1994 TABLE OF CONTENTS

I. EXECUTIVE SUMMARY...... 1

II. INTRODUCTION ...... 2

III. PURPOSE...... 3 A. Description of Problem ...... 3 B. Project Objectives...... 4

IV. APPROACH ...... 6 A. Description of Work Performed...... 6 B. Project Management ...... 12

V. FINDINGS ...... 13 A. Accomplishments and Findings...... 13 B. Significant Problems Experienced during the Project ...... 16

VI. EVALUATION ...... 17 A. Original Project Goals and Objectives ...... 17 B. Accomplishments of the Project ...... 17 C. Benefits to the Fishing Industry ...... 17 D. Economic Benefits of Project ...... 17 E. Need for Federal Assistance ...... 18

VII. CONCLUSION ...... 19 A. Conclusions from the Project ...... 19 B. Success of the Project...... 19 C. Further Work Needed ...... 19

VIII. REFERENCES ...... 20

APPENDIX I. Species Profiles for Sharks of the Gulf of Mexico...... 21

APPENDIX II. CSR Conference Registration List ...... 55

APPENDIX III. CSR Conference Agenda...... 62 I. EXECUTIVE SUMMARY

An internationally recognized center of research, specifically dedicated to the multidisciplinary study and public understanding of sharks and their relatives, the skates and rays, was established at Mote Marine Laboratory (MML), Sarasota, Florida. In its first year of operation, the national Center for Shark Research (CSR) conducted and supported research and provided facilities for studies of the biology of sharks. The CSR · also served as a center for the public communication of information on sharks and for national and international exchanges on issues relating to shark biology, including sharks as a marine resource. The CSR is a coalition effort involving a number of institutions and agencies but primarily involving MML, as host site and chief research institution, working together with the U.S. Department of Commerce/National Oceanic and Atmospheric Administration/National Marine Fisheries Service/Southeast Fisheries Science Center (NMFS/SEFSC).

1 II. INTRODUCTION

Throughout the world's oceans there live about 900 species of elasmobranch fishes, comprising about 300 species of sharks and 600 species of skates and rays. About 60 shark species and 50 species of skates and rays inhabit the coastal waters of the United States. Despite this biological diversity, the general public tends to treat sharks as just another single group of fish. But in fact, these animals are very different biologically from the other fishes, and human interactions with these animals-including utilization of them as a marine resource-call for a special approach to the understanding and conservation of these important members of the ocean environment.

Shark research dates back at least to the time of Aristotle, and yet, through over 2,000 years of scientific study, this group of vertebrate animals remains elusive and largely unknown. This is not so much due to a lack of importance or interest in sharks, but rather to the inherent difficulties of working on these large marine predators. Sharks are a challenge to work on in the open sea, while in the laboratory they are susceptible to the stresses of confinement.

Despite these problems, significant progress in shark research has been made over the past 50 years, especially during the 1960's and 1970's when funding by such agencies as the Office of Naval Research promoted innovative approaches to understanding the basic biology of sharks. Many comprehensive, published works were produced during this era of shark research (e.g. Gilbert, 1963;· Gilbert et aI., 1967; Hodgson and Mathewson, 1978). This period not only provided much new information but also spawned an interest in using elasmobranchs as models in basic research, including biomedical studies, given both their unique biology and their commonality with humans as vertebrate animals.

Today, sharks, skates, and rays have become important to man both as a research subject and as a fishery resource. By the late 1980's, the U.S. shark fishery reached an all-time high in commercial landings of shark meat and fins. The National Marine Fisheries Service (NMFS) determined that sharks had been overfished during the 1980's by nearly 6,000 metric tons (over 13 million pounds) per year in U.S. waters of the Atlantic, Gulf of Mexico, and Caribbean (NMFS, 1993). In the state of Florida alone-a focal point for the domestic shark fishery-commercial landings of shark meat doubled between 1986 and 1987, and reached over 6 .5 million pounds whole weight landed in-state in 1989 (FDNR, 1989). These landings corresponded to well over 120,000 sharks off-loaded in Florida ports alone in 1989. The recreational fishery also grew significantly in this region, with a doubling of catches of sharks by sportfishermen in the Florida Gulf in the seven years between 1979 and 1986. In recent years, however, catches have declined in certain sectors of the recr_eational shark fishery (Hueter, 1991).

2 III. PURPOSE

A. Description of Problem

The abrupt rate of growth of the domestic shark fishery, coupled with the well­ documented vulnerability, due · to their slow reproductive turnover, of shark populations to intensive fishing (Holden, 1974), led the federal fishery management councils on the U.S. east coast (Mid-Atlantic, New England, South Atlantic, Gulf of Mexico, and Caribbean Councils) to call for the implementation of a comprehensive management program for the fishery. The councils' request to the Secretary of Commerce resulted in the implementation of the first Fishery Management Plan (FMP) to cover the U.S. east coast shark fishery in federal waters (NMFS, 1993). The plan, which was implemented in April 1993, includes seasons and quotas for the commercial fishery and bag limits for the recreational fishery. An adjustment procedure for modifying the regulations was also written into the FMP.

The research data required to fine-tune this plan are difficult to obtain. In many cases, critical information on the basic life history and population biology of shark species lags far behind the current need for management. Extrapolating such information from teleost models has limited value, for sharks cannot be treated the same way as the other fishes from either a scientific or a management standpoint. Their particular biology, including a reproductive system more like that of mammals than bony fishes, and their special interactions with man, including shark attack, make them unique in the sea.

The need for a dedicated Center for Shark Research, therefore, comes from both basic and applied research. · Because of their key position in vertebrate evolution, their ecological role as apex marine predators, and their unique relationship to human activities, including their expanding value as a fisheries resource, sharks are a much sought-after subject for a broad spectrum of both basic and applied research. This research ranges from biochemistry, microbiology, genetics, anatomy, and physiology, to behavior, ecology, population biology, and fisheries science. But the logistical difficulties of working on these animals are many, and these difficulties have crippled the advancement of shark research. With the establishment of a national Center for Shark Research, researchers with a cross-section of interests from many scientific fields, and who come from both the U.S. and abroad, can design and implement innovative, multi-faceted programs utilizing the diverse resources of the Center as a home base.

In addition, such a Center can serve as a liaison agency with national and international groups interested in shark research and utilization. For example, Mexico has become a major shark-fishing nation, with about 137 million pounds of shark meat landed in their commercial fishery in 1988. The impact of this fishery, at least in the

3 Gulf of Mexico, is of concern both to Mexican government officials and U.S. interests based in the Gulf. The Center for Shark Research can serve as an independent entity for coordinating the concerns and efforts of both U.S. and Mexican groups in those areas where interaction in the shark fishery occurs. Other nations that could be involved in this way include Cuba and Japan. Furthermore, with the Center as a national and international focal point for issues dealing with sharks, its resources can be made available for information exchange involving a wide variety of users, including public policy makers, the media, and the public at large.

Previously, no such center has existed in the U.S. either for concentrated scientific study or for public exchange of information on issues dealing with, or related to, the biology, life history, and utilization of sharks, skates, and rays. The result of this void has been twofold: a lack of scientific data on many aspects of basic shark biology, thereby limiting such applications as management decisions for shark fisheries; and a perpetuation of myths and misinformation about sharks among the public and the media, leading to a vicious circle of misunderstanding of the value of sharks and shark research. Such misunderstanding manifests itself in many ways. One example is the practice of "finning" sharks for commercial gain, in which only the fins of sharks are cut off and the rest of the anima·1 is discarded, in some cases still alive. Such an abuse of a valuable marine resource can only be deterred through an increased public understanding resulting from good research.

B. Project Objectives

The primary goal of this project was to establish the national Center for Shark Research (CSR) at Mote Marine Laboratory (MML) in Sarasota, Florida, and to meet the following objectives in the first year of CSR operation:

1) conduct and advance basic and.applied scientific research on sharks, skates, and rays; 2) communicate scientific research and news about sharks; . 3) provide scientific information on sharks to public policy makers; 4) expand scientific cooperation in national and international issues involving sharks and shark biology; and 5) increase public understanding of the biology and importance of sharks, skates, and rays.

The primary scientific purpose of the CSR is to bring together and support a working group of scientists, both in-house and visiting, in conjunction with a unique combination of research facilities for shark research, in order to .advance contemporary, interdisciplinary studies of the sharks, skates, and rays. These studies cut across both basic and applied research. The CSR is designed to provide a focus

4 as well as longer-term stability for these studies, so that innovative approaches to the solution of research problems involving sharks can be utilized. With the need for research data relevant to the management of the commercial and recreational shark fishery, an emphasis was placed initially on research projects on the population biology, life history, and ecology of sharks, and other biological information relating to shark fisheries and stock assessment. The Center is designed to work closely with NMFS staff to facilitate research in those designated areas.

MML was the most logical choice to house the national Center for Shark Research for many reasons. The Laboratory has a long history of shark research spanning nearly four decades, beginning with the directorship of Dr. Eugenie Clark and continuing through that of Dr. Perry Gilbert. With recent additions to its facilities and staff, MML is today one of the world's premier research institutions at which a diversity of scientists can conduct studies on living sharks. Laboratory personnel includes several doctoral-level scientists with research experience on sharks and related fishes, and the research programs conducted by these scientists and their staff reflect a diversified approach to the study of shark biology. In addition, the long history of MML shark research has established .a reputation that attracts an international array of visiting scientists from many institutions to the Laboratory.

MML is located on a seven-acre site on City Island fronting on both Sarasota Bay and New Pass connecting with the Gulf of Mexico. The main research building of 23,500 square feet includes: a library of over 3,000 volumes, 350 serials, 16,000 reprints, and computerized reference search capabilities; sixteen research laboratories; seawater-supplied wet laboratories; a cell culture laboratory; an image analysis and photomicroscopy room; a walk-in freezer; a staff seminar room; and a 450-seat conference hall. Specimen holding facilities supplied with filtered natural seawater include six environmentally controlled rooms, a tidally fed semi-natural lagoon and a 135,000-galion natural seawater aquarium to maintain large experimental animals. The Laboratory's location provides easy access to an -unusually large number of elasmobranch fishes, comprising at least 20'species of sharks and 10 species of rays and skates. Collection of these animals requires minimum transport from sea to boat to aquarium or laboratory, and over two-thirds of these species have been maintained in captivity at the Laboratory.

Furthermore, MML is well-equipped to serve the need for public information on shark research and fishery resources, including full-time education and public communications departments which have informed hundreds of thousands of students and the general public about marine scientific research. In addition, the location of the Laboratory on the Gulf coast of Florida places it strategically in the heart of commercial and recreational shark fisheries of the Gulf of Mexico, U.S. south Atlantic, and Caribbean Sea. The Sarasota location also is near several major NMFS laboratories and offices, including those in Miami, St. Petersburg, and Pana!l1a City, which are the primary federal institutions in the southeast U.S. involved in research and management issues relating to shark fisheries.

5 IV. APPROACH

A. Description of Work Performed

To meet the objectives outlined above, the CSR in its first funding period (June 1, 1992 to July 31, 1993) performed the following activities: 1) targeted Center research areas and implemented resident and visiting scientist research projects; 2) conducted public awareness and outreach programs to scientific · and fisheries constituencies, media and the general public; and 3) organized, sponsored and hosted an international conference on the conservation and management of shark populations in the Gulf of Mexico and Caribbean region.

1. Research. The following summarizes the various research activities targeted and implemented by the CSR in its first year:

a. Shark nursery areas of the Gulf of Mexico. The primary research directive for the CSR in Year 1 was establishment of a broad-based program to investigate shark nursery areas of the Gulf of Mexico. ·· These investigations were composed of the following segments: 1) field surveys by CSR staff of coastal waters of the eastern Gulf; 2) field surveys by NMFS collaborators of coastal waters of the northeastern Gulf; 3) expansion of CSR shark-tagging program to study residence time, migration, and age and growth of juvenile sharks; and 4) development of species profiles for shark species utilizing U.S. Gulf coastal waters as nursery areas.

CSR field surveys. Exploratory surveys of eastern Gulf inshore waters for shark nursery areas were conducted primarily using the MML net boat R/V Tiburon, and a 400 yd long . by 9 Y2 ft deep gill net composed of all 4%" stretch . mesh with a monofilament diameter of 0.52 mm. These field surveys were coordinated with similar activities in Tampa Bay and Charlotte Harbor, Florida, which were part of a project funded concurrently by NMFS/MARFIN. Types of data collected in these surveys included the following: 1. Gear Description: type; mesh size (stretch mesh); set time; etc. 2. Physical Data: locality (description and lat/long by Voyager SportNav hand­ held LORAN unit); depth (by Signet depth sounder); tide; salinity, conductivity, and water temperature (by Beckman induction salinometer) at mid-depth; bottom type; etc.

3. Total Shark Catch: species; number; sex; stage of maturity (neonate = open umbilical scar, immature = non-neonate juvenile, and mature = sexually mature adult); length (precaudal, fork, total, and stretch total); weight (by Manley 2013 brass spring scales); live vs. dead; etc. Live sharks were tagged and released, with condition at release noted (see below). Stomach contents, reproductive tissue, blood, and other specimens were taken from dead sharks.

6 4. Total Bony Fish Catch: species; number; fork length (up to 10 individuals per species per set); etc. Live large gamefish (cobia, black drum, red drum, spotted seatrout, and snook) were tagged with Florida Marine Research Institute (FDEP/FMRI) tags and released; cobia were also tagged with MML cobia-amberjack-dolphin (CAD) tags and rele9sed. 5. Other Vertebrate Catch (rays, skates, sea turtles, marine mammals): species; number; size (disc width for rays and skates, straight carapace length for turtles, total length for marine mammals); etc. Live turtles were tagged with NMFS flipper tags. Shark condition after capture was scored with a "vitality code" using the following criteria: Condition 1 (Good) - No revival time required when shark is returned to the water. Rapid swimming away upon release, usually with a vigorous splash. Condition 2 (Fair) - No revival time required. Slow but strong swimming away upon release. Condition 3 (Poor) - Short revival time (up to 30 sec) required. Once revived, slow but sometimes atypical swimming away upon release. Condition 4 (Very poor) - Long revival time (more than 30 sec). Once revived, limited or no swimming observed upon release but respiration functional. Condition 5 (Dead) - Dead upon removal from gear, or moribund and unable to revive even after long submergence time. This coding allows for estimates of catch-release mortality based-on proportional returns of tags by condition factor.

NMFS collaborative surveys. A collaborative research program on the small shark fauna (small adults and juveniles) of eastern Gulf inshore waters was initiated between the CSR and staff of the NMFS Panama City Laboratory. NMFS personnel under the direction of Dr. Lee Trent utilized gill net collections to cap.ture, identify, measure and tag juvenile and small adult sharks of the northeastern Gulf under separate NMFS funding. Methodology used in these NMFS/Panama City activities was coordinated with the CSR program to the maximum extent possible in order to extend the nursery area surveys to the northeastern Gulf. CSR shark tags (see below) were supplied to the NMFS program and were deployed in live sharks collected during the NMFS surveys. Databases for the CSR and NMFS projects were made compatible so that complete sharing of data collected by both programs was made possible. To coordinate these various activities, two meetings between CSR and NMFS/Panama City personnel (one in Sarasota, one in Panama City) were held during the project period. The result of this collaboration is an ongoing, joint effort to map the nursery areas for sharks in the eastern Gulf from the Mississippi River to the Florida Keys. [Specific research data and results of NMFS surveys are available from NMFS personnel at the Panama City Laboratory and are not reported here.]

7 Tagging program. A tagging program directed toward juvenile and small adult sharks inhabiting the study areas was incorporated into the field surveys. This tagging program was designed to study catch-and-release mortality, assess residence time in nursery areas, and follow aging and growth of the young sharks. Based upon the results of a tag development and testing program funded concurrently by NMFS/MARFIN, a Ha"print modified POB dart tag was used for the field tagging. This tag was custom-manufactured to project specifications and supplied at a cost of approximately $0.62 per tag. The tag consists of a 1.5 cm-Iong nylon head of 2-3 mm thickness, with a single 2 mm-wide barb 1.5 cm in length, and a 12.5 cm-Iong plastic streamer of 1.5 mm thickness molded directly to the head. -The streamer consists of two segments molded together: a 6 cm yellow segment proximal to the tag head, and a 6.5 cm orange segment distal to the head. Tag number-and recapture information are printed on each segment, with instructions to the recapturing angler to cut off the distal orange segment and send to MML. This design accomplishes two objectives: 1) each tag serves as a double tag for multiple recaptures of the same fish, while at the same time requiring only a single tag application; and 2) return of the distal segment provides physical evidence of the tag and its number, while still allowing the recapturing fisherman to re-release the tagged shark, if desired, without removing the entire tag.

Tags were applied to sharks by puncture through the skin with a 4 mm-wide, hollow, sharpened, stainless steel applicator. The tag head was inserted on the shark's left side at the base of the first dorsal fin, through the basal cartilages just below the fin and well above the vertebral column, -and penetrating just across the shark's midline. Streamer angle was about 30° from the caudad longitudinal axis, and the tag barb was oriented projecting toward the midline. The tag was advanced until . the point of the applicator could barely be felt through the skin on the opposite (right) side of the shark. Retracting the applicator left the tag well-anchored in the cartilage above the vertebral column, not merely in the dorsal musculature. Information about the shark tags for fishermen was distributed along the Florida Gulf coast and a reward of a limited edition MML Shark Tagging Program fisherman's cap (retail value approx. $7.50) was offered to each fisherman returning tag recapture information. Fishermen recapturing tagged sharks were interviewed for data that included date and location of recapture, shark and tag condition, length and weight of shark, and fishing gear used.

Species profiles. A search was conducted for existing information on shark species utilizing Gulf of Mexico coastal waters as nursery areas. This included information from several sources: 1) a literature search for ichthyofaunal records of shark juveniles in inshore regions; 2) technical reports, computerized databases, and other "gray" literature provided by ichthyologists and fishery biologists with local knowledge of the Gulf coast; 3) state landings records and recreational fishery surveys; and 4) the MML/CSR database of shark collections. From this ~ompiled information, species profiles were written for seven relatively abundant species inhabiting the Gulf (nurse shark, Ginglymostoma ckratum; blacknose shark,

8 Carcharhinus acronotus; spinner shark, C. brevipinna; bull shark, C. leucas; blacktip shark, C. limbatus; lemon shark, Negaprion brevirostris; and bonnethead shark, Sphyrna tiburo). The species profiles represent the summaries of all information discovered in the literature and database searches.

b. Food habits of coastal shark species. Food habits of Gulf sharks collected in field surveys were investigated as follows. Stomachs were dissected from dead sharks by cutting anteriorly at the esophagus and posteriorly at the duodenum or colon, and were transported in plastic bags on ice to the laboratory. Those that could not be examined immediately were stored frozen until contents could be analyzed. Fresh or thawed stomachs were cut open lengthwise and contents were transferred onto a plastic dish, sorted, identified to the lowest taxon possible, weighed to the nearest 0.01 g (wet weight)', and preserved in 70% isopropyl alcohol. Data were recorded on laboratory data sheets and results were analyzed using appropriate statistics.

c. Population dynamics of shark populations. A new effort at Mote Marine Laboratory in the area of population dynamics and demographic analyses of sharks was implemented with the addition of Dr. Enric Cortes as Postdoctoral Scientist in the CSR's first year of operation. Dr. Cortes, previously an elasmobranch feeding specialist, received training at the University of Miami/Rosenstiel School of Marine and Atmospheric Science and at the University of Barcelona, Spain. After arriving at the CSR, Dr. Cortes began intensive training in principles of population dynamics as applied to elasmobranch species. His first species of study for this work was the Atlantic sharpnose shark, Rhizoprionodon terraenovae. Using available life history and fishery catch data, Dr. Cortes was able to conduct a demographic analysis of the status of sharpnose populations in the Gulf of Mexico. Dr. Cortes also assisted with new collaborations with scientists from Mexico (see below).

d. CSR visiting/collaborating scientist program. The primary initiative in the CSR's visiting scientist/collaborator program was establishment of new research ties with Mexico. Biologists from the Mexican SEPESCA/lnstituto Nacional de la Pesca (INP) met with CSR staff in Sarasota and planned a new, collaborative shark research program. This program was designed to operate in conjunction with the MEXUS-Gulf program, a cooperative program between the INP and NMFS.The Mexican research initiatives primarily involved establishment of a shark nursery survey and tagging program in Mexican inshore waters of the Gulf of Mexico in coordination with similar CSR activities in U.S. waters.

In addition to the Mexican initiative, other visiting scientists/collaborators who worked with CSR staff in their respective areas of res'earch included the following: Dr. Jose Castro (NMFS/SEFSC), shark reproductive biology and early life history; Jack Casey (NMFS/NEFSC), shark tag9in9 and migration; Dr. Lee Trent (NMFS/,?EFSC)' shark species composition and abundance; Dr. Eric Prince (NMFS/SEFSC), tagging methodology; Dr. Ray Wilson (University of South Florida), shark population genetics;

9 Dr. George Henderson (Florida Department of Environmental Protection), mercury levels in shark tissues; Dr. Philip Motta (University of South Florida) and Dr. Timothy Tricas (Florida Institute of Technology), functional morphology of shark feeding mechanisms; Dr. Betts Rasmussen (Oregon Graduate Institute), shark endocrinology and pheromones; Drs. Christopher Murphy (University of Wisconsin) and Howard Howland (Cornell University)' shark vision; Dr. Martin Klinger (Southern Research Institute), shark ampullary biochemistry; and Drs. Robert Thommes and James Woods (Laboratory for Comparative Endocrinology), histology of shark tissues.

e. CSR research facilities improvements. A number of improvements were made to existing MML facilities for shark research, in order to enhance opportunities for resident and visiting CSR research. These included acquisition of basic research supplies to support a broad base of research needs. Donations of major equipment to the program were accepted; these included a cryostat for frozen sectioning of tissues and a camera system for the image analysis laboratory. A CSR shark research boat designed to collect small sharks in inshore wate(s was re-fitted to accommodate larger collecting gear and more fishery-independent . work. The two main improvements to facilities were: 1) installation of a large tank "farm" on the west side of the main MML research building, which greatly enhanced the CSR's ability to maintain a variety of captive elasmobranchs (equipment paid for with MML funds); and 2) equipping of a small seawater "wet lab" in the research building west wing, which included a specially designed tank adaptable to a wide variety of physiological . and behavioral experiments as well as underwater photography of specimens (equipment also paid for with MML funds).

f. Participation in research conferences/symposia. In the first year of operation, CSR staff participated in a number of conferences and symposia covering a broad range of subjects involving elasmobranch biology. These included the following: Conservation and Management of Shark . Populations of the Gulf of Mexico and . Caribbean Region, MML/CSR, Sarasota, Florida (organized and hosted by CSR [see below] and with CSR staff giving presentations); American Society of Ichthyologists & Herpetologists/American Elasmobranch Society, two annual meetings during the project period, Champaign, Illinois and Austin, Texas (presentations; CSR director served as AES president in 1993); Symposium on Biology of the White Shark, Bodega Bay, California (panel participation); National Conference on Reauthorization of the Magnuson Act, New Orleans, Louisiana; and Florida Academy of Sciences, St. Petersburg, Florida (presentation).

2. Public awareness. A public education and outreach program was established at the CSR to meet the informational needs of the general public, educational groups, the media, science and fisheries constituents, and other interested parties. This program was coordinated by the CSR using the MML public communications staff and facilities. In the first year of CSR operation, the public awareness program took a three-pronged approach, as follows:

10 a. CSR newsletter. A regular newsletter entitled The Shark Line was instituted to provide scientists, fisheries groups, the media, and the general public with information and news on shark research and related topics. Issues of this 4-8 page newsletter were published in fall 1992, spring 1993, and summer 1993 and included articles on CSR activities, CSR staff biographies, shark fishery management, shark nursery and tagging studies, CSR shark conferences, and sharks and cancer. A question-and-answer page (tlQ&AtI) responded to questions from readers, an educational page (tlShark Schoolingtl) dealt with educational material, a puzzle section ("Mindbogglers") used shark-related facts to work problems and puzzles, and a short information column ("Shark Bites") gave brief overviews of selected areas of shark biology. These various items were written primarily by CSR staff from the research, education, and public communications divisions, and included line and B/W photo art. The Shark Line eventually adopted a standard two-color, eight-page format to be printed and distributed biannually.

b. CSR Shark Facts and Stats sheets. These single-sheet, two-page fact sheets written and produced by CSR staff provided summary information on specific topics of interest. In the first year, Shark Facts and Stats sheets were printed and distributed on the following four topics: general characteristics · of sharks; shark distribution and diversity; shark· attacks; and shark conservation. The ·fact sheets were illustrated with line art to explain portions of the text.

c. Responses to correspondence and other direct requests for information. This category of activity included responding to letters, faxes, and telephone calls from the public and media requesting information from the CSR on sharks, skates, and rays. Responses were written by CSR research staff personnel and/or public communications/education staff. A correspondence file was maintained by the CSR public information assistant during the project. By the end of the project year, many of these requests were being handled by providing copies of the relevant Shark Facts and Stats sheets, The Shark Line, and one of a series of generically written form letters on several common topics. The CSR research staff also conducted numerous media interviews and delivered a number of public lectures on shark research, fisheries, and conservation during the year.

3. Conference. An international conference on the conservation and management of shark populations inhabiting the Gulf of Mexico, U.S. south Atlantic, and Caribbean Sea was planned, organized, and hosted at the CSR during Year 1. This conference brought together shark biologists, fishery scientists, commercial fishery representatives, seafood 1Jroduct dealers, resource managers and economists, marine conservation advocates, and public information specialists to focus attention on the issues and problems associated with utilization of shark populations in the region. These problems include: 1) lack of information on shark stocks (species identification, genetic basis, absolute abundance, etc.); 2) resolution of shark life history limitations with their directed utilization as a fishery resource; 3) shark bycatch issues; and 4) regional and international conflicts in shark conservation and management. The

11 conference agenda was developed by the CSR Director together with NMFS staff from the SEFSC and NEFSC. Invitations to participants were issued approximately six months prior to the conference date in April 1993. Participants from as many Gulf/Caribbean nations as possible were invited, including representatives from the U.S., Mexico, the Bahamas, and Cuba. The meeting was announced in a number of society newsletters and fisheries publications and was open to the public. The conference ran 2 Y2 days and was held at the 450-seat Martin-Selby Conference Center on the grounds of Mote Marine Laboratory.

B. Project Management

The Principal Investigator and Director of the CSR, Dr. Robert E. Hueter of the Mote Marine Laboratory staff, managed the activities . of the Center under the supervision of Mote Marine Laboratory Executive Director Dr. Kumar Mahadevan and Director of Research Dr. Richard Pierce. As CSR Director, Dr. Hueter was responsible for the planning, logistical and budgetary coordination, implementation, and completion of all CSR sUb-programs. Center activities were planned and executed in cooperation . with NMFS staff at the Miami, Narragansett and Panama City laboratories. Work was performed entirely by staff andvolunteer.student interns at Mote Marine Laboratory.

12 v. FINDINGS

A. Accomplishments and Findings

1. Research. The following summarizes the major results of the various research activities of the CSR in its first year:

a. Nursery areas. CSR field surveys revealed an important nursery area for the blacktip shark (Carcharhinuslimbatus) in the eastern Gulf of Mexico off Withlacoochee Bay. Neonate blacktips of 52-62 cm total length (TL) and non-neonate juveniles of 54-82 cm TL were collected in spring months in waters 2-5 m deep, 22.8-28.9%0 salinity, and 29.9-30. 7°C temperature. Sex ratio of the blacktip pups collected in this area was 1 F:1.3M. Based upon the finding of this nursery area for the blacktip, an important species for the commercial and recreational fishery, a new approach to mapping shark nurseries was subsequently designed to explore the inshore region from Cedar Key to Aripeka, Florida, and to estimate relative abundance of blacktip juveniles over time in the region. This approximately 60 mile-long stretch of Florida Gulf coastline is bordered by broad, shallow marine habitat including seagrass beds, sand/mud bottom, and nearshore oyster reefs. Freshwater outflow is widespread via the Waccasassa, Withlacoochee, Crystal, Homosassa, and other rivers in the region. Salt marshes abound along the seaward reaches of these rivers. Mangrove habitat is found as far north as Cedar Key. The coastal marine areas, especially those over seagrass bottom, are especially suitable habitat for juvenile blacktip sharks.

With the information obtained in the CSR field surveys, a two-phase project was designed to study the region. The goal 'of phase one will be to map out the area in a general way in terms of juvenile blacktip CPUE, in order to select two or three subareas of high CPUE for sampling during phase two. , Once subareas of higher blacktip CPUE have been identified, phase two (quantification) can begin. This will be carried out as follows. For each subarea, a grid of approximately 2 km x 5 km will be laid out on a chart such that the grid encloses the sites of highest CPUE identified 2 in phase one. Each square of the grid will be 1 km • This grid will be laid out according to local stratification and geographical features, such that the blacktip CPUE, as determined in phase one, is relatively high throughout the grid. Prior to each monthly sampling period, five to six squares in the grid will be selected randomly. For quantitative sampling, each of the five or six squares selected randomly will be sampled in the most logistically feasible order, using gill nets. The same type of net will be used in all phase two surveys. The gill net will be set within each square to maximize blacktip CPUE (with information from phase one) and in a manner so as not to create a hazard to navigation. The net will be picked up beginning one hour from the time the first mesh enters the water. The end time of the set will be considered as the time when the final mesh is removed from the water. In this manner, it should be possible to fully sample each subarea in one day's fishing. The plan is to 'sample normally during daylight hours, except in those subareas with higher CPUE's at night

13 as found in phase one. The two or three subareas will be sampled on consecutive days, weather permitting, once per month from March through October. For each subarea sampled during phase two, the mean CPUE will be calculated as follows:

x = (L n/Tj ) / N where nj is the number of blacktip sharks captured in grid i, Tj is the total time of the set in grid i, and N is the number of grids sampled in each subarea. Variance of each CPUE calculation will be calculated as follows: var(x) = (L[><;-X]2)/N

where Xj is (L n/Tj) for grid i (in set-hours). In this way, relative abundance of juvenile blacktips will be assessed using mean CPUE with standardized methods. Each subarea ultimately will be sampled over two years. NMFS/Panama City staff have coordinated efforts with the CSR to use the same standardized techniques of quantitative surveys for juvenile sharks in three areas of the northeastern Gulf of Mexico between St. Mark's River and Panama City. In addition, NMFS staff have planned exploratory surveys, to .be coordinated with the CSR, for the area between Panama City and Mobile.

The design and implementation of the CSR's small shark tagging program was completed. Tag development and testing were concluded (see Approach, above) and tag deployment was begun. The tag/recapture database was constructed in a Paradox format and was made compatible with other NMFS tagging program databases.' Coordination with these programs at NMFS/Narragansett, Miami, and Panama City laboratories was conducted via meetings with NMFS staff from the three laboratories. The '- NMFS Apex Predator program at the Narragansett laboratory continues to use NMFS stainless-steel M-tags to tag large sharks (> approx. 1.5 m TL) but the CSR recommended these tags not be deployed in sharks smaller than 1.5 m TL as a result of CSR testing. Based on this recommendation, NMFS/Narragansett began an examination of the feasibility of using the CSR-type nylon-head tag in their studies of juvenile blue sharks of the Atlantic.

The information search for sharks utilizing Gulf of Mexico coastal waters as nurseries resulted in seven species profiles. These profiles contain information on the following: classification; value; range; life mode; habitat; movements/migrations; reproduction; growth and development; food and feeding; and other relevant biological data. The complete species profiles are included in this report in Appendix I.

b. Food studies. The primary result of the shark feeding studies was a quantitative analysis of the diet and food habits of the bonnethead shark (Sphyrna tiburo). This information was presented at the annual . meeting of the American Elasmobranch Society and was written up for publication by CSR staff, and it is currently in press with the Bulletin of Marine Science (Cortes et. aI., in press). [Reprint copies of this paper should be available soon and will be forwarded to-NMFS.]

14 c. Population dynamics. Dr. Cortes' studies of the demography of the sharp nose shark (Rhizoprionodon terraenovae) resulted in a presentation to the American Elasmobranch Society and a paper in press with Fishery Bulletin (Cortes, in press). [Reprint copies of this paper should be available soon and will be forwarded to NMFS.]

d. Other activities. The nursery surveys, tagging program, feeding investigations, and population dynamics studies were discussed in depth with members of the Mexican Instituto Nacional de la Pesca (INP) delegation to the CSRconference in April (see below). It was decided that the CSR in cooperation with NMFS will collaborate wHh the INP in designing and implementing analogous studies along the Gulf and Caribbean coast of Mexico. In addition, both the CSR and the INP will explore new research initiatives on shark ageing and growth. Plans for this work were scheduled to be finalized at the next meeting of MEXUS-Gulf in Veracruz, Mexico.

2. Public awareness.

a. CSR publications. Copies of The Shark Line were distributed to a mailing list of nearly 2,600. Approximately half of these were members of the National Marine Educators Association (NMEA); of the remaining 1,300 recipients, 91 % were U.S. addresses and 9% were foreign addresses. In addition to this mailing list, copies of The Shark Line and Shark Facts and Stats were distributed on request to scientists, universities and laboratories, fishery organizations, conservation organizations, government agencies, resource managers, elected officials, educators, marine advisory agents, school groups, conference participants, aquarium visitors, - media representatives, private citizens and other interested parties. Response to all CSR publications was extremely positive. CSR public communication assistants also manned a CSR information booth and distributed CSR publications at five public exhibitions in Florida during the project year, including the Ocean Expo '93 in Miami in ., March 1993 .

b. Correspondence/media file. CSR public communications staff responded to a total of 181 letters (approximately one letter every 1.4 work-days) requesting information. Of these, 77% had U.S. and 23% had foreign addresses. The category breakdown of the requests was as follows: 1) wishing to be added to the CSR mailing list (25%); 2) seeking education/employment opportunities (23%); 3) general requests for information on sharks (17%); 4) requests for descriptions of research activities (14%); 5) shark conservation (7%); 6) what is the CSR? (7%); 7) requests from young children (4%); 8) shark attack information (2%); and 9) membership information for the American Elasmobranch Society (1 %). In addition to these documented written requests handled by CSR public communications staff, many other written and telephoned requests were handled by the CSR research staff during the project year. CSR personnel also were involved in a number of media interviews during the year, including a major article on shark conservation · and !isheries management in The New York Times.

15 3. Conference. The CSR's international conference entitled "Conservation and Management of Shark Populations in the Gulf of Mexico and Caribbean Region" took place at MML on April 21-23, 1993. Approximately 150 registrants (inc!. MML personnel) from four countries, including scientists, marine resource managers, commercial and recreational fishermen, fishery industry spokesmen, conservationists, educators, and legislative representatives, participated in the 2 %-day meeting (see Appendix II for meeting registration list). Participants attended joint sessions on shark biology, Mexican shark research and fisheries, U.S. commercial and recreational fisheries, education and conservation, and shark fisheries management (see Appendix III for meeting agenda). The group then split up into three workshops on research, fisheries and management, and education and communication. Following the end of the conference, CSR staff met additionally with members of the Mexican delegation to discuss the plans for establishing the collaborative research program in Mexico in cooperation with scientists from the Instituto Nacional de la Pesca (INP).

By all accounts, the conference made significant progress in the understanding and use of shark resources of the Gulf of Mexico, U.S. south Atlantic, and Caribbean Sea. The information exchanged during the conference has helped lead to new, collaborative research, fisheries management, and educational efforts involving the U.S., Mexico, and other nations with an interest in shark populations. The positive mixture and cooperation of diverse groups-such as commercial fishermen, scientists, resource managers, and conservationists-was a particularly successful feature of the · meeting and provided a blueprint for future similar meetings. Some written quotes sent to the CSR after the conference included the following: - "Your efforts to make this 'meeting of the minds' a reality were well worthwhile. It is my feeling that most of us left Sarasota with hope for the future of all sharks as a resource that cannot only be successfully managed, but utilized by the scientific community and the recreational and commercial fishing interests" (Tris Colket, commercial shark fisherman); "This meeting represented the best beginning I am aware of to really develop cooperative management of the shark resources" (Dr. Lee Trent, NMFS/SEFSC); "Please accept my sincere congratulations on a job well done. The meeting was professionally stimulating and superbly organized" (Dr. Samuel Gruber, University of Miami); and "I learned a great deal and, hopefully, now have a much better understanding of sharks and their management" (James Mathews, Staff Director of the U.S. House Subcommittee on Fisheries Management)-. In addition, NMFS chose the conference to make the historic announcement of the first-ever implementation of federal management of the U.S. shark fishery in the form of the Secretarial Fishery Management Plan (FMP) for Sharks of the Atlantic Ocean, including U.S. waters of the Gulf of Mexico and Caribbean Sea.

B. Significant Problems Experienced during the Project

No significant problems were experienced during the course of this project that impeded the original goals or objectives of the project.

16 VI. EVALUATION

A. Original Project Goals and Objectives

The original goal of this project was to establish the national Center for Shark Research at Mote Marine Laboratory and to meet the following objectives in the first year of CSR operation: 1) conduct and advance basic and applied scientific research on sharks, skates, and rays; 2) communicate scientific research and news about sharks; 3) provide scientific information on sharks to public policy makers; 4) expand scientific cooperation in national and international issues involving sharks and shark biology; and 5) increase public understanding of the biology and importance of sharks, skates, and rays.

B. Accomplishments of the Project

The project accomplished all major goals and objectives in that it: 1) produced a coordinated effort to establish new multi-disciplinary, multi-agency, multi-national efforts in shark research; 2) served the needs of thousands of U.S. and foreign citizens and groups needing information on sharks, skates, and rays; 3) sponsored a highly successful international conference on sharks involving a multiplicity of participating groups; and 4) in accomplishing #1, 2~ and 3 above, promoted the public understanding and wise use of sharks as a valuable marine resource-.

C. Benefits to the Fishing Industry

The fishing industry benefitted from all sectors of CSR activities in its first year of operation. CSR research designed to provide fishery-relevant life history information will lead to better, more informed management of shark resources and thus help to preserve the long-term survival of commercial and recreational shark fisheries. CSR public awareness programs not only provided news and information directly to fishermen but also helped to educate resource managers, educators, conservationists and the general public about the problems and needs of the shark fishing industry. Finally, the CSR conference provided a constructive venue for the discussion of fishery-relevant issues between fishermen, scientists, and fishery managers.

D. Economic Benefits of Project

This project can provide economic benefits to the fishing industry, federal and state management efforts, and multi-national scientific programs. The new research data obtained by the CSR potentially can provide economic benefits to the fishing

17 industry in the form of sustained landings of adult sharks as well as development of gear and methodology to .reduce juvenile shark bycatch. Sustainability of shark landings can be advanced by managing critical habitats for the early life stages of sharks, so that successful recruitment to adult stocks is promoted. Fishing gear and methodology can be developed that minimizes bycatch of juvenile sharks in nursery areas. This also promotes sustainability of adult shark landings, but it provides the further economic benefit of reducing shark damage to fishing gear used in coastal fisheries targeting other species. Federal and state fishery management efforts are benefitted by providing a "one-stop" facility for conducting the specific types of shark research that are required to produce and adjust shark fishery management plans. Finally, scientific efforts are benefitted by consolidating the CSR's specialized facilities and staff at an institution where visiting scientists and collaborators can work to develop their own particular programs in elasmobranch research.

E. Need for Federal Assistance

As the CSR was a new concept serving national and international needs, and since the CSR was proposed as a cooperative program with the federal government through the auspices of the Department of Commerce (NOAA/NMFS), government financing assistance was both appropriate and needed. In addition to the support from the Department of Commerce/NMFS, funds are being sought for future CSR activities from the following sources of support for which the Center for Shark Research qualifies: 1) National Science Foundation; 2) U.S. Fish and Wildlife Service; 3) Mexican CONACyT; 4) state of Florida; 4) Gulf Coast Shark Census Fund (private sector funds) ; and 5) other private foundations; corporations, and individuals.

18 VII. CONCLUSION

A. Conclusions from the Project

There are justifications and means to focus national research and information resources dealing with sharks into a single research center, the CSR. The activity level of the CSR in its first year of operation demonstrated that the need existed for new shark research data, for public information on sharks, and for open discussions of issues involving shark resources. The choice of Mote Marine Laboratory as the host site for the CSR was appropriate and wise. With the legacy of shark research at MML and the existing staff and facilities there, the CSR became well established and began to make significant contributions in its first year of operation.

B. Success of the Project

The project was successful in accomplishing all major goals and objectives, and the results will have a positive impact on a number of federal and state activities. The federal government will continue to benefit from CSR activities by having a centralized organization through which research, management, and public information issues dealing specifically with sharks and shark biology can be funneled. With the increased interest in this marine resource, and the implementation ofa federal shark fishery management plan, the government has a new vehicle- for the directing and coordination of required research and dissemination of information in response to the growing need. Since Florida and the other Gulf and south Atlantic states are the focal point for U.S. east coast commercial and recreational shark fisheries, the same benefits from CSR activities apply on the state level in that region. Furthermore, the Florida Department of Environmental Protection/Florida Marine Research Institute, which is the state's primary organization for marine research, currently conducts almost no research concentrated on sharks. The CSR, therefore, complements and does not duplicate or interfere with ongoing FDEP/FMRI activities.

C. Further Work Needed

Because the CSR is designed as a long-term program rather than a short-term, closed-end project, the work of the center is expected to continue. The original project description for the CSR contained a three-year work plan of continuing research and educational activities. With the successful establishment and functioning of the CSR, that strategy has been expanded to a five-year plan. The federal fishery management plan for sharks of the Atlantic Ocean will remain in effect indefinitely, and its continued execution by NMFS will no doubt require new information as well as new approaches to collecting and distributing that information.

19 VIII. REFERENCES

Cortes, E. Demographic analysis of the Atlantic sharpnose shark Rhizoprionodon terraenovae in the Gulf of Mexico. Fishery Bulletin 93(1) (in press) .

Cortes, E., C.A. Manire, and R.E. Hueter. Diet, feeding habits, and diel feeding chronology of the bonnethead shark, Sphyrna tiburo, in southwest Florida. Bulletin of Marine Science 58(1) (in press).

Florida Dept. of Natural Resources, Marine Fisheries Information (1989) Annual landings summaries. St. Petersburg, FI.

Gilbert, P.W., ed. (1963) Sharks and Survival. D.C. Heath, Boston. 578 pp.

Gilbert, P. W., R.F. Mathewson, and D.P. Rail, eds. (1967) Sharks, Skates, and Rays. Johns Hopkins Press, "Baltimore. 624 pp.

Hodgson, E.S. and R.F. Mathewson, eds. (1978) Sensory Biology of Sharks, Skates, and Rays. ONR, Dept. of the Navy, Arlington, Va. 666 pp.

Holden, M.J. (1974) Problems in the rational exploitation of elasmobranch - populations and some suggested solutions. ill Sea Fisheries Research (F.R. Harden Jones, ed.), pp. 117..,137. Logos Press, London.

Hueter, R.E. (1991) Survey of the Florida recreational shark fishery utilizing shark tournament and selected longline data. Final Report to FDNR, Grant Agreement 6627, St. Petersburg, Flo 94 pp.

National Marine Fisheries Service (1993) Fishery Management Plan for Sharks of the Atlantic Ocean. U.S. Dept. Commerce, NOAA/NMFS, St. Petersburg, FI. 273 pp.

20 APPENDIX I:

SPECIES PROFILES FOR SHARKS OF THE GULF OF MEXICO

Nurse shark Ginglymostoma cirratum Blacknose shark Carcharhinus acronotus Spinner shark Carcharhinus brevipinna Bull shark Carcharhinus leucas Blacktip shark Carcharhinus limbatus Lemon shark Negaprion brevirostris

Bonnetheadshark Sphyrna tiburo

CENTER. FOR SHARK RESEARCH MOTE MARINE LABORATORY SARASOTA, FLORIDA

21 SPECIES: Ginglymostoma cirratum COMMON NAME: Nurse shark

OTHER SCIENTIFIC NAMES Still in use: None Recently used: None

OTHER COMMON NAMES - None found

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Rhincodontidae

VALUE

Commercial: Usually caught on longlines and marketed fresh or salted (18 15). Often caught in artisanal fisheries (15). Hides have been used to make an exceptionally good leather; fins not utilized (2 33 18 15). The yield of liver oil is relatively low (2). Also used for fishmeal (15). Off the southern coast of Brazil, the otoliths of this species are used by local fishermen as a diuretic (2). Catch statistics are not maintained separately for this species (60).

Recreational: Nurse sharks will bite on almost any bait and are readily caught on light tackle, but they are too sluggish to offer the sportsman any challenge (2 11 15).

Ecological: Generally sluggish and harmless to bathers, but there have been a small number of unprovoked attacks on swimmers and divers (2 11 18 15). Will bite humans when provoked (33). Considered a nuisance in parts of the Antilles because it raids fish traps (11 15).

RANGE

Overall: Found from Cape Hatteras to Brazil, occasionally to Rhode Island; rare or absent from the western and northern Gulf of Mexico (2 11 26 33 1 8 36). Known from Bermuda and common around Cuba and Jamaica (2). Center of abundance from Florida to the Caribbean region (2 11 18). Also reported from the eastern Atlantic and the eastern Pacific (2 11 15), but these records are said to be for a related species (33).

Within Study Area: Locally very common in shallow water throughout the West Indies, south Florida and the Keys (2 11 14 18). A year-round resident on the Florida west coast north to Tampa and for some distance up the east coast (2). One of the most common sharks in · Florida waters, including Tampa Bay where they are found inshore in Old Tampa Bay; also found on rocky reefs offshore (14 42). Reported to be rare in the Indian River lagoon (37 65).

LIFE MODE

Primarily a bottom dwelling species, often found in small schools . . A nocturnal species exhibiting strong swimming and considerable activity at night, but sluggish during the day (1 5 72). - :

22 HABITAT

Type: Common inshore shark, found on the continental and insular shelves in tropical and subtropical waters (15). Inhabits shallow coastal waters including bays, and found in water as shallow as 0.6-3.0 m, but occurs to depths of at least 12 m (233 15). Commonly occurs around mangrove keys, outer rocky reefs, and on sand flats (264233 18 15). Schools of one to three dozen occur in shallow water (11 15). Exhibits a strong preference for daytime resting sites that they return to after a night's activity (15). Frequently seen lying motionless and close to one another on the bottom, often with the dorsal fin out of the water (2 11 18 15).

Substrate: Found on sand flats and rocky bottoms (2 42 18).

PHYSI CAL/CHEM ICAL

Temperature: Juvenile nurse sharks have been collected at temperatures ranging from 28.5° to 34°C off of southwest Florida (MML/Center for Shark Research (CSR) database). Nurse sharks have survived a wide range of temperatures when held in captivity (15). Not known to be killed in Florida by cold waters following the passage of cold fronts (61 62 63 64). Studies of tooth replacement rates in juveniles indicated a correlation with water temperatures, with the rate of tooth replacement increasing with increasing temperature; most rapid tooth replacement occurred at temperatures of 27-29°C (66).

% Salinity: Juveni.les have been collected at salinities from 17.5 to 30.0 0 off southwest Florida, with % the majority taken at salinities greater than 28 0 (MML/CSR database).

MOVEMENTS/MIGRATIONS

There is evidence for a northerly.movement in the spring and a migration to the south in the fall; found in the northern Gulf of Mexico in the warmer months. Schools sometime appear off Cape Lookout, N.C. and also taken at Charleston, S.C. in the summer (2).

REPRODUCTION

Mode: Ovoviviparous; young sustained by yolk during intrauterine development (2 11 15).

Mating & pupping: Mates in groups in shallow water (33). Klimley (59) provided a description of courtship behavior. Mating occurs year-round in shallow waters off Florida (2 11). Females apparently give birth in late spring and summer, and young are common in the Florida Keys at that time of year (14 15). Clark and von Schmidt (14) collected young from May through November in southwest Florida, and their smallest specimen (40 cm) was taken in October (14). Young nurse sharks are reportedly found year-round off Florida (11 14).

Reproductive capacity: Number of intrauterine eggs ranges from 21-28, and females produce between 20 and 30 pups per litter (2 11 18 15). Smaller females usually produce fewer pups (11).

GROWTH & DEVELOPMENT

Neonates/juveniles: Size at birth ranges from 27-29 cm (2 18).

23 Adults: Males mature at about 235 cm, and females mostly mature at 230-240 cm (15). One female 152 cm reportedly had well developed embryos [Beebe, 1941; cited in (2)]. Reported weights are 204 g for a 69.2 cm specimen, and 150-168 kg for a 259 cm individual (2). Adults ranging from 213 to 335 cm are common (2 11). Maximum total length is 425-430 cm, but most are usually < 3 m long (2 11 26 33 15).

FOOD & FEEDING

Primarily a benthic feeder which ingests its prey by suction; Tanaka (72) calculated that small nurse sharks can generate a suction equivalent to one atmosphere of pressure. Feeds heavily on bottom dwelling invertebrates including shrimp, crabs, spiny lobsters, squid, octopus, marine snails, and bivalves. Also consumes fish such as sea catfishes, mullet, puffers, and stingrays (2 11 18 15). Algae is occasionally found in the stomach (15).

Citations

2 Bigelow, H.B. and W.C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res., Yale Univ. Part I: 576.

11 Castro, J.I. 1983. The sharks of North American waters. Texas A & M Univ. Press, College Station, TX.180p. .

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15:13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2.

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

26 Hoese, H.D. and R.H. Moore. 1977. Fishes of the Gulf of Mexico: Texas, Louisiana and adjacent waters. Texas A & M Univ. Press. College Station, TX. 327p.

33 Robins, C.R., G.C. Ray, J. Douglass and R. Freud. 1986. A field guide to Atlantic coast fishes of North America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co., Boston. 354p.

36 Smith, H.R. 1907. The fishes of North Carolina. NC Geol. and Econ. Surv. 2:454p.

37 Snelson, F.F. and S.E. Williams. 1981. Notes on the occurrence, distribution and biology of . elasmobranch fishes in the Indian River Lagoon system, Florida. Estuaries 4: 110-120.

42 Springer, V.G. and K.D. Woodburn. 1960. An ecological study of the fishes ofthe Tampa Bay area. FL State Bd. Conserv. Prof. Pap. Ser. No.1: 1 04p.

59 Klimley, P.A. 1980. Observations of the courtship and copulation in the nurse shark, Ginglymostoma cirratum. Copeia 1980:878-882.

60 Florida Department of Natural Resources. 1989. Summary of Florida Commercial -Landings, 1976-1989. Fla. Dept. Nat. Res., 24p.

24 61 Storey, M. 1937. The relation between normal range and mortality of fishes due to cold at Sanibel Island, Florida. Ecol. 18( 1): 1 0-26.

62 Storey, M. and E.W. Gudger. 1936. Mortality of fishes due to cold at Sanibel Island, Florida. Ecol. 17(4):640-648.

63 Snelson, F.F., Jr., and W.K. Bradley, Jr. 1978. Mortality of fishes due to cold on the east coast of Florida, January 1977. Fla. Sci. 41: 1-12.

64 Gilmore, R.G ., L.H. Bullock, and F.H. Berry. 1978. Hypothermal mortality in marine fishes of south­ central Florida, January, 1977. NE Gulf Sci. 2(2):77-97.

65 Gilmore, R.G. 1977. Fishes of the Indian River Lagoon and adjacent waters, Florida. Bull. Fla. State Mus., BioI. Sci. 22(3):101-118.

66 Luer, C.A., P.C. Blum and P.W. Gilbert. 1990. Rate of tooth replacement in -the nurse shark, Ginglymostoma cirratum. Copeia 1990: 182-191.

67 Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. Amer. Fish. Soc., Spec. Pub. 20, 183p.

72 Myrberg, A.A., Jr. and S.H. Gruber. 1974. The behavior of the bonnethead shark, Sphyrna tiburo. Copeia 1974:358-374.

25 SPECIES: Carcharhinus acronotus COMMON NAME: Blacknose shark

OTHER SCIENTIFIC NAMES Squalus acronotus Poey, 1860; holotype

OTHER COMMON NAMES - sand shark (42)

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Carcharhinidae

VALUE

Commercial: No directed fishery for the species exists throughout its range (57)' but commercial landings are primarily from off southeast Florida and the northeast coast of Venezuela, where it is caught incidentally to other species (18 15). Most often caught with surface long lines (18 15) and with gill nets set close to shore (11). Marketed dry salted for human consumption (1 8 1 5).

Recreational: Not specifically sought by sport fishermen in most areas, but caught while fishing for other species (2 14).

Ecological: Often preyed upon by other sharks, particularly bull sharks and tiger sharks (14 56).

RANGE

Overall: In the western Atlantic, from North Carolina (where it is rare) through Florida and the Gulf of Mexico to southern Brazil (2 11 33 18 15). Abundant in coastal waters from the Carolinas to Florida and the Gulf of Mexico during the summer and fall months (11). Castro (1 2) found this species to -be extremely abundant in shallow water during the summer in South Carolina (12). Also occurs in the Bahamas, Virgin Islands, Antilles and Puerto Rico (15).

Within Study Area: -Abundant throughout Florida waters, particularly the southeastern and southwestern coasts during the summer and fall (2 11 14 18). Springer and Woodburn (42) reported it as abundant about one mile offshore near Tampa Bay in the late summer. Also reported as common near Sarasota from March through November with greatest catches during May (14).

LIFE MODE

Nektonic. Common in tropical and warm temperate coastal waters of the continental shelves (18 15), especially in summer in shallow water 2-4 m deep (12).

HABITAT

Type: Found in shallow inshore coastal waters. Neonates and juveniles occur near piers where they are caught in July-August by sport fishermen in North Carolina (57). Adults occur in coastal waters

26 from depths of 2-4 m out to depths of 34-38 m, particularly in the summer months (2 11 14 17 18 151257).

Substrate: Found mainly over sand, shell and coralline bottoms (18 15), but also occur over sand-silt substrates (57).

PHYSICAL/CHEMICAL

Temperature: Caught in nearshore shallow waters (9 to 18 m deep) off North Carolina at temperatures ranging from 10° to 32 °C (57). Schwartz (57) reported the species in lower salinity estuaries in North Carolina when water temperatures ranged from 23° to 29°C. Schwartz (57) found no relationship between catch and environmental parameters. One neonate was collected off southwest Florida at a temperature of 29°C (MML/CSR database). Off southwest Florida, juveniles have been taken at temperatures of 17.3°-34.0° and adults were collected at temperatures of 24.00-32.00C, but both life stages were more commonly collected at temperatures greater than 30.00C (MML/CSR database).

Salinity: Found in salinities ranging from 28 to 34%0 in coastal waters off North Carolina (57). Also % reported in North Carolina estuaries at salinities from 15 to 22 0 (57). One neonate was collected off southwest Florida at a salinity of 3r/oo (MML/CSR database). Juveniles were collected at salinities of 25-37° /00 off southwest Florida, but there was no apparent relationship between catch and salinity (MML/CSR database) . No relationship between catch and salinity could be detected in North Carolina waters (57). Adult blacknose sharks have been taken at salinities of 29-36.2 %0 off southwest Florida, and most were collected at salinities greater than 33%0 (MML/CSR database).

MOVEMENTS/MIGRATIONS

Schwartz (57) noted that there seems to be a constant exchange of blacknose sharks into and out of North Carolina, possibly from Florida and the Gulf of Mexico. This proposed migration was suggested by age and growth data, as well as reproductive state of females and the t iming of the appearance of young sharks in North Carolina waters. Schwartz was unable to substantiate this migratory behavior through tag return data.

REPRODUCTION

Mode: Viviparous, with a yolk-sac placenta (18 15). Fertilization is internal.

Mating & pupping: Clark and von Schmidt (14) proposed a spring mating period for the species based on the capture of a female with large ovarian eggs and a mature male with seminal vesicles full of sperm. Schwartz (57), however; reported that mating occurs in August in North Carolina based on the presence of open wounds or scars on mature females. The gestation period has been estimated to be 9 months (57), or to range from 10 months to 2 years (17). Females are reported to give birth from January through April in Florida (2 11 15), in May and June in the Gulf of Mexico and on the Florida east coast (3 11 14 17), and in the summer off the Carolinas (11 12 57). Neonates have been collected in June off southwest Florida (MML/CSR database).

Reproductive capacity: Number of pupsllitter usually three to six (2 11 14 18 15 56).

27 GROWTH & DEVELOPMENT

Size at birth in the Gulf of Mexico has been reported as 45-50 cm TL (2 3 14); neonates collected off southwest Florida were 46-48 cm TL (MML/CSR database). Dodrill (17) stated that pups are 41.7 to 49.5 cm at birth on the Florida Atlantic coast. Schwartz (57) calculated size at birth to be 50.5 cm in North Carolina based on four embryos 49.5 to 51 cm removed from a pregnant female. The smallest free swimming specimen collected by Castro (12) off South Carolina was 51.2 cm TL. Schwartz (57) provided the following equations for converting fork length to total length:

males: TL = -10.76 + 1.25(FL) females: TL = 5.41 + 1.22(FL)

Size at maturity has been variously reported as 101 cm TL in Florida (56)' 103 cm TL off Sarasota, Florida (14), 114 cm TL in the northern Gulf of Mexico (4), 106 cm TL on the Atlantic coast of Florida (17), and 110 cm TL in North Carolina (57). Gravid females collected in the northern Gulf ranged from 113.4 to 126 cm TL (4), two females collected at Sarasota, FL both 118 cm TL carried embryos (14), and females about 120 cm TL carrying well advanced pups were reported in North Carolina (57). Schwartz (57) presented the following von Bertalanffy growth equations: males: L(t) 1.887 (1 - el-o.11 7It+2.01ll) females: L(t) = 1.650 (1 - e [-0.138It+2.68ll)

Fish lengths back-calculated from these equations agreed well with observed data for males but yielded higher than expected values for females. .

Maximum size has been variously reported as 140 cm (11), 150 cm (33), 152 to 183 cm (2), and possibly as large as 200 cm, with females reaching at least 137 cm (15).

FOOD & FEEDING

Stomach contents of blacknose sharks caught in the northern Gulf of Mexico included octopus tentacles and fish remains (Micropogonias undulatus and Stenotomus caprinus)(4). Juveniles have been observed actively feeding on schools of anchovies along Gulf beaches (4). Stated to feed on small fishes, including pinfish and porcupine fish (11 14 18 15). Preyed upon by other sharks; adult blacknose sharks are frequently taken from stomachs of bull and tiger sharks (56), and they are often eaten by other sharks when caught on set lines (14).

PARASITES

Five species of cestodes including Phoreiobothrium triloculatum, P. lasium, Platybothrium cervinum, Phyllobothrium sp. 2, and Acanthobothrium sp. 4, have been found in the spiral valves of blacknose sharks caught in North carolina (58).

Citations

2 Bigelow, H.B. and W.C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found.

Mar. Res., Yale Univ. Part I: 576. 0-

28 3 Branstetter, S. 1986. Biological parameters of the sharks of the northeastern Gulf of Mexico in relation to their potential as a commercial fishery resource. PhD Diss. , Texas A & M Univ., ·College Station, TX: 138p.

4 Branstetter, S. 1981. Biological notes on the sharks of the north central Gulf of Mexico. Cont. Mar. Sci. 24: 13-34.

11 Castro, J.1. 1983. The sharks of North American waters. Texas A & M Univ. Press, College Station, TX. 180p.

12 Castro, J .1. 1993. The shark nursery of Bulls Bay, South Carolina, with a review of the shark nurseries of the southeastern United States. Environ. BioI. Fish. 38:37-48.

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15:13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2.

17 Dodrill, J.W. 1977. A hook and line survey of the sharks found within five hundred meters of shore along Melbourne Beach, Brevard County, Florida. MS Thesis, Florida Inst. Tech., Melbourne. 304p.

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

33 Robins, C.R, G.C. Ray, J. Douglass and R Freud. 1986. A field guide to Atlantic coast fishes of North America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co., Boston. 354p.

42 Springer, V.G. and K.D. Woodburn. 1960. An ecological study of the fishes of the Tampa Bay area. FL State Bd. Conserv. Prof. Pap. Ser. No.1: 1 04p.

47 Vorenberg, M .M. 1962. Cannibalistic tendencies of lemon and bull sharks. Copeia 1982:455-456.

56 Springer, S. 1938. Notes on the sharks of Florida. Proc. Fla. Acad. Sci. 3:9-41.

57 Schwartz, F.J. 1984. Occurrence, abundance, and biology of blacknose shark, Carcharhinus acronotus in North Carolina. NE Gulf Sci. 7:29-41 .

58 Hester, W.W. 1981. Cestodes from the spiral valves of elasmobranch fishes from North Carolina. MS Thesis, Appalachian St. Univ., Boone, NC, 65p.

67 Robins, C.R, RM. Bailey, C.E. Bond, J.R Brooker, E.A. Lachner, RN. Lea, and W.B. Scott. 1991. Common and sCientific names of fishes from the United States and Canada. Amer. Fish . Soc., Spec. Pub. 20, 183p.

29 SPECIES: Carcharhinus brevipinna COMMON NAME: Spinner shark

OTHER SCIENTIFIC NAMES Recently used: Carcharhinus maculipinnis (Poey) (2 14)

OTHER COMMON NAMES - large black-tipped shark (2)

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Carcharhinidae

VALUE

Commercial: Caught as part of the fishery throughout much of its range (15), especially in Cuba, the northern Gulf of Mexico, and the east coast of Florida (18). Caught mainly with floating longlines (18 15), but also with bottom nets, and on hook and line (15). Meat is marketed fresh (11 15) or dried and salted (15). The hide, fins and liver oil (vitamins) are also utilized (15). Separate catch statistics are not reported for this species (60).

Recreational: Offers a challenge to sport fishermen when caught on rod and reel because it puts up a stubborn fight (11). Known for its spectacular spinning leaps from which it gets its name (33).

Ecological: One attack on a swimmer has been recorded, but it is not generally considered to be dangerous to man (11).

RANGE

Overall: Distribution is nearly circumtropical although the number of localities from which specimens are known is relatively small (11 19 33 18 15); apparently absent in the eastern Pacific (11 18). In the western Atlantic from North Carolina through the northern Gulf of Mexico to Brazil (11 19 33 18 15 7).

Within Study Area: Common in coastal Waters of Florida and the northern Gulf of Mexico (2 62 11 1 4 1 9 1 8 1 5 7).

LIFE MODE

A fast-moving, schooling, coastal-pelagic species often seen leaping out of the water while spinning (11 18 15). The spinning leaps are said to occur when a feeding shark charges through a school of small fish with a spinning motion and with its mouth open, then breaks the surface of the water (11 18). Very little is known about the life history of this species (4).

HABITAT

Type: Waters of the continental and insular shelves; common both close inshore and offshore (15).

30 Common in water depths of less than 30 m and occurring to at least 75 m; occurs from the surface to the bottom (11 15 7). Neonates and juveniles reported from estuarine waters in South Carolina (12).

Substrate: No substrate preference mentioned in the literature.

PHYSICAL/CHEMICAL

Temperature: Juveniles were collected off west-central Florida at temperatures ranging from 24.8° to 30.0 0 C (MML/CSR database). South African tagging studies indicate that young prefer lower water temperature than adults (15).

Salinity: Off southwest Florida, juveniles have been collected at salinities of 28.5-36.2%0 (MML/CSR database).

MOVEMENTS/MIGRATIONS

Highly migratory off Florida and in the Gulf of Mexico. Adults exhibit an inshore migration for feeding and reproduction during the spring and summer, followed by a southward, offshore migration in the fall and winter (15). A similar pattern of inshore migration during the warm months with an offshore movement as temperatures decrease has been suggested for the species in South African waters (15).

REPRODUCTION

Mode: Internal fertilization. Viviparous with a yolk-sac placenta (11 15).

Mating & pupping: Males are reported to mature between 159 and 203 cm, and females at 170 to 200 cm (15). Branstetter (3), however, stated that both males and females mature at a length of about 110 cm in the northern Gulf of Mexico. He collected a mature male measuring 114 cm and a mature female measuring 110 cm. Castro (11) reported that males mature at about 170 cm and females at about 180 cm. The smallest mature male captured off Sarasota, FL was 188 cm (14). The mating season in the northern Gulf of Mexico is primarily in late June and early July (3). Gestation period has been reported to be 11-12 months in the northern Gulf of Mexico (3), and 12 to 1 5 months off South Africa (15). Pups are born in spring and early summer in the Gulf of Mexico and off Louisiana (3 11 15). It has been suggested that females produce young every other year rather than every year (3).

Reproductive capacity: Number of pups per litter ranges from 3 to 15 (2 11 15); average litter size is 7 (3).

GROWTH & DEVELOPMENT

Pups measure 60-75 cm at birth (11 15). Branstetter (3) estimated a birth size of 60-70 cm based on his catches in the northern Gulf of Mexico. His smallest free swimming specimen was 68 cm. Females grow larger than males. Maximum size reported is 233 cm for males and 278 cm for females (15). Other authors report maximum size as 250 cm (26) and 300 cm (33).

31 FOOD & FEEDING

Frequently feeds on schools of small fishes by swimming rapidly upward through the school with its mouth open, spinning as it goes, then shooting out of the water after its feeding run (15). Diet consists mainly of fish including ladyfish, herrings, anchovies, sea catfish, mullet, bluefish, tunas, jacks, small sharks and rays, and other species (11 15). Also feeds on squid and octopi (11 15).

MISCELLANEOUS

Often confused with blacktip sharks (11 14 15). which may account for the lack of information about some aspects of its life history.

Citations

2 Bigelow, H.B. and W.C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res., Yale Univ. Part I: 576.

3 Branstetter, S. 1986. Biological parameters of the sharks of the northeastern Gulf of Mexico in relation to their potential as a commercial fishery resource. PhD Diss., Texas A & M Univ., College Station, TX: 138p.

4 Branstetter, S. 1981. Biological notes on the sharks of the north central Gulf of Mexico. Cont. Mar. Sci. 24: 13-34.

7 Briggs, J.C. 1958. A list of Florida fishes and their distribution. Bull. FI. State Mus., BioI. Ser. 2(8):223-318.

11 Castro, J.1. 1983. The sharks of North American waters. Texas A & M Univ. Press, College Station, TX. 180p.

12 Castro, J.1. 1993. The shark nursery of Bulls Bay, South Carolina, with a review of the shark nurseries of the southeastern United States. Environ. BioI. Fish. 38:37-48.

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15:13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2.

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

19 Garrick, J.A.F. 1982. Sharks of the genus Carcharhinus. NOAA Tech. Rep. NMFS Circ. 445: 194p.

26 Hoese, H.D. and RH. Moore. 1977. Fishes of the Gulf of Mexico: Texas, Louisiana and adjacent waters. Texas A & M Univ. Press. College Station, TX. 327p.

33 Robins, C.R, G.C. Ray, J. Douglass and R Freud. 1986. A field guide to Atlantic coast fishes of North America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co., Boston. 354p. ~

32 60 Florida Department of Natural Resources. 1989. Summary of Florida Commercial Landings, 1976-1989. Fla. Dept. Nat. Res. , 24p.

67 Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N . Lea, and W.B. Scott. 1991 . Common and scientific names of fishes from the United States and Canada. Amer. Fish. Soc., Spec. Pub. 20, 183p.

33 SPECIES: Carcharhinus leucas COMMON NAME: Bull shark

OTHER SCIENTIFIC NAMES Recently used: none found

OTHER COMMON NAMES - cub shark (2 34), ground shark (2)

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Carcharhinidae

VALUE

Commercial: Primarily caught on long lines set for other commercial fishes (tuna, swordfish)(1 015 18); will take almost any bait, but prefers shark or ray. Flesh is edible and is sold fresh, fresh frozen and smoked (15), but primarily used for fish meal (18 15). The hide is of good Quality and is used for leather (11 18 15). Fins are used for shark-fin soup, and the liver for oil which is extracted for vitamins, particularly vitamin A (1815). Many shrimp fishermen have recently changed to long line rigs to catch sharks because of the high demand for shark fins in the Orient.

Recreational: A popular game fish particularly in the southeast Atlantic and the Gulf of Mexico, and off South Africa (15). Caught with rod and reel (15). The majority of sharks caught are released or discarded, with some being used as mounted trophies or used for food at home. In the Gulf of Mexico, bull sharks comprise 7 % by- number and 11 .4 % by weight of the shark species caught by recreational fishermen (10).

Ecological: Sharks are considered as apex predators; bull sharks represent the top carnivore in many estuarine systems (10).

RANGE

Overall: Primarily a coastal species, it is cosmopolitan in tropical-subtropical areas and it also ranges into some temperate regions (11 33 18 15). In the western Atlantic, its range extends from Massachusetts to southern Brazil (1 9 33 1 8 7 34). Most abundant in the Gulf of Mexico and Caribbean areas (2 11 19 18). Penetrates as far up the Mississippi River as Alton, Illinois (45). Seldom seen offshore (33).

Within Study Area: One of the most common large sharks in nearshore coastal waters of Florida (37 38). Commonly caught in the Tampa Bay area (42), and reported as the most abundant shark species in the Indian River Lagoon (37 38). Also reported as the most common shark off Sarasota (14). Found in freshwater rivers on the Florida west coast (49).

LIFE MODE

Bull sharks are nektonic. They are found from the nearshore marine zone to freshwater riversj2 11).

34 HABITAT

Type: Coastal, estuarine, riverine and lacustrine environments. Usually found inshore in waters < 30m deep (2 15). Commonly found in bays, lagoons, tidal passes, river mouths, near wharves, and just off the surf line (2 11 15). Often ascend rivers for long distances in freshwater (2 11 2245 49 43 30). Reported to move onto coral reefs from deep water around dusk (92) .

Substrate: Considered a bottom-living species, it is often found in muddy areas with few other shark competitors (15 18).

PHYSICAL/CHEMICAL:

Temperature: Off southwest Florida, neonates have been collected at temperatures of 29.8 ° -32.2 ° C, with most occurring at temperatures between 31.5°and 32.1°C; juveniles were reported from temperatures of 21.5°-35°C, with the majority collected between 29.8° and 30.4°C (MML/CSR database). Snelson et al (38) collected juvenile bull sharks in the Indian River Lagoon system of Florida at temperatures ranging from 20.0-32.00C, and reported two individuals that succumbed to hypothermal stress at a temperature of about 8.00C during January. Bull sharks were not captured during the winter in the Indian River Lagoon, but it was suggested that this absence reflected depressed activity caused by low water temperatures (10-1 5 ° C) rather than emigration of sharks from the Lagoon (38). Branstetter (pers. comm.) suggested 18.0 0C to be the limiting temperature before bull sharks advance into the estuaries. Thomerson (45) suggested water temperature as the limiting factor for the advancement of C. leucas up the Mississippi River. He found that sharks move up the river only when water temperatures are >24.00C, particularly in the summer and fall.

Salinity: Occurs in brackish or freshwater, mainly as pups -and juveniles but also as adult females (2 11 15). This occurrence may be related to inshore migrations of the females for parturition-(19 38). After birth, the juveniles often spend considerable time in these brackish waters (19). Juveniles found off southwest Florida in waters of 23.1 to 28.2°100, with most occurring at salinities> 27° /00 (MML/CSR database) . Branstetter (3) noted that these sharks are concentrated around freshwater inflows, or at least the fishery for them is. One study reported the collection of juveniles from a salinity range of 1.6 to 2.3%0 (28). One small juvenile was collected in the lower Myakka Hiver, FL where the salinity was 3 .0%0 following a week of heavy rainstorms (MML/CSR database) . Collected in freshwater rivers of southwest Florida (4944), and in salinities ranging from 18 to 44%0 in the Indian River Lagoon (37). Newborns have been taken at salinities of 0.8%0 in Shark River, FL [D. Wright and T. Kranzer (pers. comm.); cited in Loftus and Kushlan (49)]. Thomerson (45) reported that C. leucas is the only shark known to be able to deal with the osmotic demands of either fresh water or sea water for periods of at least months and probably years.

MOVEMENTS AND MIGRATIONS

Movements of adult female sharks to estuarine nursery areas appears to be mainly for parturition (15) . Young remain in these inshore nursery areas, but juveniles and adults move into deeper coastal waters (4 9 38 18 15 12). Other movements are probably associated with changing temperatures. In the western Atlantic, a north and south migration coinciding with spring and fall occurs along the US east coast (40 15).

35 REPRODUCTION

Mode: Fertilization is internal. Viviparous with a yolk-sac placenta (15).

Mating and parturition: In the northern Gulf of Mexico, gravid females are caught in July and August, with pups being born in April and May, suggesting a gestation period of 10-11 months (4). Data from bull sharks collected at Sarasota, FL indicate that mating takes place in June and July in the Gulf of Mexico, with pups being born in April, May and June (14); neonate bulls have been collected in July and August off west-central Florida (MML/CSR database). Gestation probably lasts 10-11 months (4 11 14 15). Females move into brackish water to give birth and the young utilize these areas as nurseries (4 9 14 38 18 12 41).

Reproductive Capacity: The number of pups per litter ranges from 1 to 13 (18 15). Snelson et al (38) took a 249 cm TL female with 12 near term embryos. Most investigators report litters of 4-5 (2 14). Females apparently do not bear young every year (14 38).

GROWTH AND DEVELOPMENT

Embryos: Development is viviparous; embryos initially dependent on stored yolk but are later nourished by mother through a placental connection (15). Dodrill (17) proposed that during uterine development one or more pups may develop to extraordinary size at the expense of other litter mates.

Juveniles: Size at birth ranges from 56-81 cm TL (4 6 3 11 38 15) and averages around 75 cm TL (11 38). Neonates collected off southwest Florida measured from 66 cm to 84 cm TL (MML/CSR database). Caillouet et al. (9) showed no significant differences between lengths or weights for male and female neonates shortly after birth. They (9) presented the following length-weight relationships: Males: Log W = 2.90(Log L) - 4.96 r2 = 0.82 Females: Log W = 3.06(Log L) - 5.26 r2 = 0.98

where W = weight in grams and L = length in cm.

Juvenile weights increase rapidly as maturity approaches (4). Branstetter and Stiles (6) estimated growth rates were 15-20 cm/yr for the first five years, 10 cm/yr for 6-10 year old sharks, 5-7 cm/yr for 11-16 year old sharks, and less than 4-5 cm/yr for sharks older than 16 years.

Adults: Smallest mature male reported was 212 em TL; smallest mature female was 228 cm TL (4). Males mature at 210-220 cm TL or 14-15 years of age; females mature at > 225 em TL at an estimated age of 18 years (6). Females grow larger than males (3 14). Adult size reported as 225-300 em TL for males and 233-300 cm TL for females (30). Reported to grow as large as 350 cm (33).

FOOD AND FEEDING

Bull sharks have broad feeding habits, preying on a wide variety of organisms (89). Capable of capturing fast swimming fish, but will consume almost any type of animal matter available (dead or alive)(89). There is evidence of selective feeding, with bull sharks passing over abundant fish species and consuming much less abundant species (38). Stomach contents are reported to consist of squid (Loligo sp.) and f ishes (Stenotomus caprinus, Diplectrum formosum, Anchoa hepsetus, Brevoortia spp.)(4). Other bony fishes reported from the stomachs of bull sharks are: Archosargus probatocephalus, Caranx sp., Centropomus undecimalis, Euthynnus alleteratus, Arius felis, Lactophrys

36 tricornis, Mega/ops at/anticus, Mugi/ sp. (4), Anguilla rostrata, Roccus american us, and Micropogonias undu/atus (35). Snelson et al (38) reported teleosts in the stomachs of 80% of the bull sharks they captured. Echinoderms, molluscs, crustaceans, reptiles, and other items have been found in bull shark stomachs (91).

Castro (11) noted that bull sharks feed on other sharks, preying heavily on small sandbar sharks, rays, bony fishes, molluscs, and crustaceans. Marine mammal flesh has also been found in the stomachs of bull sharks (89). Incidents of cannibalism were ' provoked' by Vorenberg (47), but have also been reported from bull sharks captured in the wild (38). Jaws commonly contain spines from rays (4). Snelson et al (38) suggested that catfishes (Arius fe/is, 8agre marinus) and stingrays (Dasyatis sabina, D. saYI) are very important food items in the diet of bull sharks.

Ecological Interactions and Notes: Bull sharks are a top carnivore with slow growth and relatively low reproductive capacity. Because of these factors only a limited commercial and sport fishery for these sharks can be sustained.

PERSONS CONSULTED

Larry Massey, NOAA, National Marine Fisheries Service, Southeast Fisheries Center, 75 Virginia Beach Drive, Miami, FL 33149

Steve Branstetter, Gulf and South Atlantic Fisheries Development Foundation, Lincoln Center, Suite 997, 5401 W. Kennedy Blvd., Tampa, Florida 33609

Citations

2 Bigelow, H.B. and W.C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res., Yale Univ. Part I: 576.

3 Branstetter, S. 1986. Biological parameters of the sharks of the northeastern Gulf of Mexico in relation to their potential as a commercial fishery resource. PhD Diss., Texas A & M Univ., College Station, TX: 138p.

4 Branstetter, S. 1981. Biological notes on the sharks of the north central Gulf of Mexico. Cont. Mar. Sci. 24: 13-34.

6 Branstetter, S. and R. Stiles. 1987. Age and growth of the bull shark, Carcharhinus /eucas, from the northern Gulf of Mexico. Environ. BioI. Fish. 20:169-181.

7 Briggs, J.C. 1958. A list of Florida fishes and their distribution. Bull. FI: State Mus., BioI. Ser. 2(8}:223-318.

9 Caillouet, C.W., Jr., W.S. Perret and B.J. Fontenot, Jr. 1969. Weight, length and sex ratio of immature bull sharks, Carcharhinus /eucas, from Vermillion Bay, Louisiana. Copeia 1969: 196-197.

10 Casey, J .G. and J.J. Hoey. 1985. Estimated catches of large sharks by US recreational fishermen in the Atlantic and Gulf of Mexico. NOAA Tech. Rep. NMFS 31 :22 p.

11 Castro, J.I. 1983. The sharks of North American waters. Texas A & M Univ. Press, College-Station, TX. 180p.

37 12 Castro, J.I. 1993. The shark nursery of Bulls Bay, South Carolina, with a review of the shark nurseries of the southeastern United States. Environ. BioI. Fish. 38:37-48.

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15: 13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2 .

17 Dodrill, J.W. 1977. A hook and line survey of the sharks found within five hundred meters of shore along Melbourne Beach, Brevard County, Florida. MS Thesis, Florida Inst. Tech., Melbourne. 304p.

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

19 Garrick, J .A .F. 1982. Sharks ofthe genus Carcharhinus. NOAA Tech. Rep . NMFS Circ. 445: 194p.

22 Gunter, G. 1938. Notes on invasion of fresh water by fishes of the Gulf of Mexico, with special reference to the Mississippi-Atchafalaya River system. Copeia 1938:68-72.

28 Keyyey, J.R., Jr. 1965. A taxonomic survey of the fishes of Delta National Wildlife Refuge with emphasis upon distribution and abundance. MS Thesis, La . State Univ., Shreveport, LA. 133p.

30 Lee, D.S., C.R.Gilbert, C.H. Hocutt, R.E. Jenkins, D.E. McAllister and J.R. Stuffer, Jr.. 1980. Atlas of North American Freshwater Fishes. NC BioI. Surv. Publ. #1980-12, 867p.

33 Robins, C.R., G.C. Ray, J. Douglass and R. Freud. 1986. A field guide to Atlantic coast fishes of N. America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co., Boston. 354p.

34 Schwartz, F.J. 1959. Two eight-foot cub sharks, Carcharhinus leucas (Muller and Henle) captured in Chesapeake Bay. Copeia 1959:251-252.

35 Schwartz, F.W. 1960. Additional comments on adult bull sharks Carcharhinus leucas (Muller and Henle), from Chesapeake Bay, Maryland. Ches. Sci. 1 :68-71.

37 Snelson, F.F. and S.E. Williams. 1981. Notes on the occurrence, distribution and biology of elasmobranch fishes in the Indian River Lagoon system, Florida. Estuaries 4: 110-120.

38 Snelson, F.F., T.J. Mulligan and S.E. Williams. 1984. Food habits, occurrence and population structure of the bull shark, Carcharhinus leucas, in Florida coastal lagoons. Bull. Mar. Sci. 34:71-80.

40 Springer, S. 1960. Natural history of the sandbar shark Eulamia milberti. US Fish & Wildl. Servo Fish. Bull. 61 :1-38.

41 Springer, S. 1967. Social organization of shark populations. pp. 149- 174. IN: P. W Gilbert, R. F. Matheson and D.P. Ralls [Eds.]. Sharks, skates and rays. Johns Hopkins Press, Baltimore.

42 Springer, V.G. and K.D. Woodburn. 1960. An ecological study of the fishes of the Tampa Bay area. FL State Bd. Conserv. Prof. Pap. Ser. No.1 :104p.

43 Swift, C., R.W. Yerger and P.R. Parrish. 1977. Distribution and natural history of the fresh and brackish water fishes of the Ochlocknee River, Florida and Georgia. Bull. Tall Timbers -Res. Sta. 20:1-111.

38 44 Tabb, D.C., B. Drummond and N. Kenny. 1974. Coastal marshes of southern Florida as habitat for fishes and effects of changes in water supply on these habitats. Final Rep . to Bur. Sport Fish Wildl. (Contract No. 14-16-004-56), Univ . Miami, Miami, FL.

45 Thomerson, J.E. and T.B. Thorson. 1977. The bull shark, Carcharhinus /eucas, from the upper Mississippi River near Alton, Illinois. Copeia 1977: 166-168.

47 Vorenberg, M.M. 1962. Cannibalistic tendencies of lemon and bull sharks. Copeia 1982:455-456.

49 Loftus, W.F. and J.A. Kushlan. 1987. Freshwater fishes of southern Florida. Bull. Fla. State Mus. 31 (4):344p.

67 Robins, C.R., R.M. Bailey, C.E. Bond, J.R. Brooker, E.A . Lachner, R.N. Lea, and W.B. Scott. 1991 . Common and scientific names of fishes from the United States and Canada. Amer. Fish. Soc., Spec. Pub. 20, 183p.

89 Wetherbee, B.M., S.H. Gruber and E. Cortes. 1990. Diet, feeding habits, digestion, and consumption in sharks, with special reference to the lemon shark, Negaprion brevirostris. In: Elasmobranchs as living resources. H.1. Pratt, Jr., S.H. Gruber, and T.Tan

91 Banner, A. 1972. Use of sound in predation by young lemon sharks, Negaprion brevirostris (Poey). Bull. Mar. Sci. 22:251-283.

39 SPECIES: Carcharhinus limbatus COMMON NAME: Blacktip shark

OTHER SCIENTIFIC NAMES Recently used: none found

OTHER COMMON NAMES - spot-fin shark (32) small black-tipped shark (2)

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Carcharhinidae

VALUE

Commercial: Caught with floating longlines, hook-and-line, bottom trawls, and fixed bottom nets (15 18). Marketed fresh, fresh-frozen, or salted, also used for fish meal (11 15 18). Various subproducts such as the liver used for oil (1 5 1 8). Skin is also used for leather (11 1 5).

Recreational: Often fished for sport, and usually caught by trolling or stillfishing .offshore (11 15). Often puts up a fast, lively fight and may leap out of the water (15).

Ecological: Although some "hit-and-run" attacks on humans are recorded regularly in certain places, such as off the Florida east coast, these attacks are rarely serious and blacktips generally are not considered to be a hazard to people (15).

RANGE

Overall: Found worldwide in all tropical and subtropical waters (15 26 33). In the western Atlantic, from Massachusetts to Brazil (152633), off northeast Florida and throughout the Gulf of Mexico (11 15). Reported in the eastern tropical Pacific from lower California to Peru (2 15).

Within Study Area: Distributed throughout Florida waters (7), and the most common shark in the Bahamas and off southern Florida (1 8). The most abundant medium-sized shark in the coastal waters of the Gulf of Mexico in summer (93).

LIFE MODE

A very active and fast-swimming species (15). Pelagic, often coming into inshore waters in large schools in association with Spanish mackerel (1 5 1 8 33). Often found over continental or insular shelves, but not truly oceanic (15). Usually found in offshore or coastal waters frequently in aggregations of 6 or more (33 18). Sometimes seen in schools at the surface (2 15).

HABITAT

Type: Young use shallow beach and bay areas as nursery grounds (5). Foundclose inshore,-off river mouths, in estuaries, shallow muddy bays, higher salinity portions of mangrove swamps, and along

40 dropoffs on coral reefs (15). Frequently the most common shark in clear water cuts and along beaches in Florida and the Bahamas (33), and one of the most common pelagic sharks around south Florida (15 32). Seldom occur in water deeper than 30 m (15).

Substrate: Not known to prefer a particular substrate.

PHYSICALICHEMICAL

Temperature: Blacktip sharks have been reported in water temperatures ranging from 22 ° to 33 ° C in Texas and Florida (68 69 70 71). Neonates have been collected off southwest Florida at temperatures from 25.0° to 31.0 0 C, and were most abundant at temperatures above 28°C; juveniles have been taken at temperatures ranging from 18.5° to 33.0 0 C, but most occurred at temperatures greater than 26°C (MMLlCSR database).

% Salinity: Collected in Texas and Florida at salinities ranging from 15-35 0 (68 69 70 71). Off southwest Florida, neonates and juveniles have been collected at salinities of 24.2-37.0% 0, but both life stages were most abundant at salinities greater than 300/00 (MMLlCSR database). Can tolerate reduced salinities in estuaries and near river mouths, but does not penetrate far into fresh water (15).

MOVEMENTS/MIGRATIONS

Seasonally migratory and absent during the winter months off Florida (15). Pregnant females are apparently migratory off South Africa (15).

REPRODUCTION

Mode: Fertilization is internal; reproduction is viviparous, with a yolk-sac placenta (11 15).

Mating & parturition: Males mature at a length of 130-135 cm (4-5 ft) and at an age of 4-5 years (2 5 11 93). Females mature at a length of 150-155 cm (5 11 1493) and at an age of 6-6.8 years (5). In Florida, mating occurs in June and July (5). Gestation period extends from 10 to 12 months (3 11 15). Young are born in late spring through early summer (11 14 15 93). A 3 to 4 week parturition period extending from late May to early June reportedly occurs in the Tampa Bay area (5), but neonates have been collected from early May through the end of June in Tampa Bay and Charlotte Harbor (MMLlCSR database). Females are thought to produce young only in alternate years (15).

Reproductive capacity: Fecundity has been variously reported as 4-6 embryos (111. 1-10 embryos (1 5 18), and 3-9 embryos, with 4-7 the most common (2 15).

GROWTH & DEVELOPMENT

Juveniles/adults: Size at birth ranges from 38-72 cm (515 18); neonates collected in Tampa Bay and Charlotte Harbor, FI ranged from 52-66 cm (MMLlCSR database). Smallest neonates reported from Florida were 62 cm, but the species exhibits rapid neonatal growth (5). Growth rates are 25-30 cm during the first year; 20 cm/yr during second year; 10 cm/yr through adolescence; 5-7 cm/yr after maturity (5). Branstetter (5) gave the following equation to convert from fork length to to!al length:

TL = 1.16 (FL) + 5.71

41 Branstetter and McEachran (93) gave the following equation for conversion from total length to fork length:

FL = 0.843 (TU + 2.93 n = 140, r = .993

Total length (cm) at age were given by Branstetter and McEachran (93) as: age 0 = 62; age 1 + = 1 02-112; age 2 + = 113-120; age 3 + = 119-131; age 4 + = 128-144; age 5 + = 135-148; age 6 + = 150-165; age 7 + = 152-171; age 8 + = 167-171. Maximum size reported as 152-198 cm (214), although others give the figure of 255 cm (1533). Largest males in Florida were 8.6 years of age and largest females ranged from 8 to 9.3 years of age (5 93). Reported to attain a maximum age of 12 years off Africa (15).

FOOD & FEEDING

Feeds primarily on small fishes; consumes menhaden, sardines and other herring, mullet, jacks, groupers, other schooling fishes, various species of rays, squid, and octopi (2 3 11 14 15 18). Remains of crabs and lobsters have also been found in their stomachs (14 15). Small blacktips have been found in the stomachs of other sharks (2).

Citations

2 Bigelow, H.B. and W.C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res., Yale Univ. Part I: 576.

3 Branstetter, S. 1986. Biological parameters of the sharks of the northeastern Gulf of Mexico in relation to their potential as a commercial fishery resource. PhD Diss., Texas A & M Univ., College Station, TX: 138p.

5 Branstetter, S. 1987. Age and growth estimates for blacktip, Carcharhinus limbatus, and spinner, C. brevipinna, sharks from the northwestern Gulf of Mexico. Copeia 1987:964-974.

7 Briggs, J.C. 1958. A list of Florida fishes and their distribution. Bull. FI. State Mus., BioI. Ser. 2(8):223-318.

11 Castro, J.1. 1983. The sharks of North American waters. Texas A & M Univ. Press, College Station, TX.180p.

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15:13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2.

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

26 Hoese, H.D. and R.H. Moore. 1977. Fishes of the Gulf of Mexico: Texas, Louisiana and adjacent waters. Texas A & M Univ. Press. College Station, TX. 327p.

32 Reid, G.K., Jr. 1954. An ecological study of the Gulf of Mexico fishes in the vicinity of Cecipr Key, Florida. Bull. Mar. Sci. Gulf & Caribb. 4(1):1-94.

42 33 Robins, C.R., G.C. Ray, J . Douglass and R. Freud. 1986. A field guide to Atlantic coast fishes of North America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co., Boston. 354p.

67 Robins, C.R., R.M . Bailey, C.E. Bond, J.R. Brooker, E.A. Lachner, R.N. Lea, and W .B. Scott. 1991 . Common and scientific names of fishes from the United States and Canada. Amer. Fish. Soc., Spec. Pub. 20, 183p.

68 Roessler, M. A. 1967. Observations on the seasonal occurrence and life histories of fishes in Buttonwood Canal, Everglades National Park, Florida. PhD Diss., Univ. of Miami, Coral Gables, FL 155p.

69 Reid, G.K., Jr. 1955. A summer study of the biology and ecology of East Bay, Texas. Part II. The fish fauna of East Bay, the Gulf Beach, and summary. Tex. J. Sci. 7(4):430-453.

70 Schultz, R.L. 1962. A survey and inventory of vertebrate species present in Mesquite Bay and Cedar Bayou. Proj. Rep. Mar. Fish. Div. Tex. Game & Fish Comm. for '1960 -61. 15p.

71 Tabb, D.C. and R.B. Manning. 1961. A checklist of the flora and fauna of Northern Florida Bay and adjacent brackish waters of the Florida mainland collected during the period July 1957 through September 1960. Bull. Mar. Sci. Gulf Caribb. 11 (4):552-649.

93 Branstetter, S. and J.D; McEachran. 1986. Age and growth of four carcharhinid sharks common to the Gulf of Mexico: A summary paper. In: Indo-Pacific Fish Biology: Proceedings of the 2nd International Conference on Indo-Pacific fishes.

43 SPECIES: Negaprion brevirostris COMMON NAME: Lemon shark

OTHER SCIENTIFIC NAMES Recently used: Hypoprion brevirostris Poey (84)

OTHER COMMON NAMES - none found

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Carcharhinidae

VALUE

Commercial: Widely caught where it occurs, primarily on longlines, but also on other gear (15). Caught for their livers which are used for oil (2 1 5 1 8 54) and their fins which are used for gelatine and shark-fin soup (15 18). Pursued for their hide which is said to make a leather of good quality (11 1 5 54). Also sought for their flesh reported to be a good quality meat which is sold dried salted, smoked, and fresh frozen (11 15 54). Carcasses are used for fishmeal (15).

Recreational: Often sought by recreational anglers in marsh channels with the best fishing being at night (11 26).

Ecological: Known to be dangerous to man (11 33 18). They have been responsible for attacks on people in boats, and for unprovoked attacks on swimmers and bathers; most attacks have resulted after the sharks were assaulted by divers or fishermen (15). Lemon sharks are popular for experimental work (11), and they have been the subject of long-term behavioral and ecological studies (15). Lipids from the liver have been shown to increase mammalian resistance to disease (24).

RANGE

Overall: Found in the temperate and tropical Atlantic from New Jersey (rarely) to Brazil and throughout the Gulf of Mexico (2 1 5 1 8 26 33 84). Common from South Carolina to Florida (11). Also occur in western Africa (2 33) and are common in the tropical eastern Pacific (15 1854). Particularly abundant off Florida and on the Bahamas Bank (54), but most abundant in the Caribbean Sea (11 18). Not known from Bermuda (2).

Within Study Area: Distributed throughout Florida waters including the Dry Tortugas (7 84). Adults arid juveniles occur occasionally in the southern portion of the Indian -River Lagoon, and are most common there in the spring and summer months (17 37 65). Neonates and juveniles are common in mangrove fringes and over grassbeds in enclosed bays and sounds throughout the Florida Keys (16).

LIFE MODE

A demersal species found primarily in coastal waters but occasionally entering river mO!Jths (18). Young lemon sharks are highly social (81). Occur singly or in loose aggregations of up to 20 individuals (15 54); groups of sharks are seen more frequently than lone individuals (21). Large

44 schools observed in the winter (33). Active during both day and night, with maximum activity around dawn and dusk (15 21). Active at night around docks and other structures (11). Often exhibit a definite site specificity, usually returning to the same site each day, but apparently not territorial (20 21 81). Young inhabit a limited home range of 6-8 km 2 (15), and one mature female tracked ultrasonically for almost 5 days, occupied an area of 93 km 2 (21). Size of the home range expands with age (21 81), and it may encompass about 300 km2 as they become subadults (1 5) .

HABITAT

Type: Found in inshore and coastal waters, including bays and inlets, from the surface and intertidal down to at least 92 m (15 33), not found more than a very short distance from land (2) . Prefers the shallower waters over sand or coral mud (54), and common around coral keys, docks, mangrove fringes, in river mouths, and in saltwater creeks (2 15). Juveniles tracked in the Bahamas routinely swam or rested among the roots of the mangrove thicket (87). The young are more abundant in shallow water « 18 m) than are the adults (54). The home range of most juveniles at Bimini, Bahamas encompassed shallow, narrow expanses of water very close to shore (81). At Bimini, juveniles implanted with ultrasonic transmitters were found to select shallower, warmer water with underlying rocky or sandy substrate, and they avoided areas of dense seagrass (87). May enter fresh water but they do not penetrate far up coastal rivers, and they are not partial to brackish waters (15 54).

Substrate: In shallower waters found over rock, sand, coral and mud (15 54 87).

PHYSICAL/CHEMICAL

Temperature: Off southwest Florida, neonates have been collected at water temperatures from 22.0° to 31.00C, and juveniles have been taken at temperatures of 30.4°-33.00C (MML/CSR database). Young have been collected at temperatures of 20.6° to 31.4°C in Florida Bay (73). Tagged juveniles at Bimini, Bahamas selected water temperatures greater than · 30°C (87). Adults and juveniles collected in the summer in the Indian River Lagoon at temperatures between 27-31°C (37). The species apparently tolerates high temperatures well (54).

Salinity: Reported from freshwater in Brazil (2). Neonate lemon sharks have been collected at 26.5-37.00/00, and juveniles at 24-37%0 off southwest Florida (MML/CSR database). Schmidt (73) caught young lemon sharks in Florida Bay at a salinity range of 31.5 to 40.2%0. Collected at salinities of 32-42%0 in the Indian River Lagoon (37) .

Oxygen: Lemon sharks are adapted for activity in environments with low oxygen concentrations (15).

Turbidity: Young have been collected in Florida Bay at turbidities of 0.5 to 3.3 NTU (73).

MOVEMENTS/MIGRATIONS

Young do not migrate during first year of life, but remain within a limited home range and exhibit a definite site specificity (15 20 21 81). Young may make infrequent long-distance excursions out of their home range (81). Off Florida, lemon sharks migrate to the south and into deeper waters at the onset of winter (15 17 37).

45 REPRODUCTION

Mode: Fertilization is internal; viviparous, with a yolk-sac placenta (11 15 18).

Mating & parturition: Sexual maturity is said to be reached between 213 and 229 cm (2), or at lengths greater than 229 cm (54) . Males mature at about 225 cm and females at 240 cm (15). The smallest mature females caught in southwest Florida were 252 cm (14). Two authors reported that maturity occurs at an age of 1.5-2.6 years (14 54), but Brown and Gruber (55) found that males mature at an age of 11.6 years and females at 12.7 years. Mating occurs in spring and summer (May-September) in the western Atlantic (2 11 14 15). Seasonal mating aggregations have been reported off the west coast of Florida (15). Gestation period is about 10-12 months (11 15 43). Young are born in the spring and summer (11 14 26 54 79). Neonates have been collected in May off central west peninsular Florida (MMLlCSR database). Parturition occurs in shallow nursery areas, and females may remain in these areas for considerable periods of time (15). Florida Bay is said to be an important nursery ground (54). Evidence provided by Clark and von Schmidt (14) suggests that females may produce young only every other year.

Reproductive capacity: Fecundity ranges from 5 to 19 embryos (11 14 15 18 54), w ith 11 the average (11 54) .

GROWTH & DEVELOPMENT

Juveniles: Young are 61-66 cm at birth and grow as much as 10 cm in their first 40 days (54). Neonates measuring 60-66 cm Tl have been collected off southwest Florida' (MMLlCSR database). Clark and von Schmidt (14) estimated a juvenile growth rate of 8 em/month based on the growth of one female kept in captivity. Gruber (20) found that juveniles in the wild (72 cm average length) grew at the rate of 0.23 mm/day but captive animals grew at 0 .62 mm/day. Gruber and Stout (79) estimated that young lemon sharks probably grow between 10 and 20 cm/year, and that the growth rate does not exceed 25 em/year. Cortes (90) found that growth was directly correlated w ith food intake, but that growth leveled off at high food rations. It has been suggested that the major factor responsible for the slow rate of growth of lemon sharks results from a low rate of food consumption and a slow rate of food passage through the digestive tract (79 82). Gruber and Stout (79) gave the following equation to covert total length (Tl) to precaudal length (PCl):

PCl = 0 .76 Tl + 2.85 r2 = 0.99, N = 71

Brown and Gruber (55) calculated the von Bertalanffy equation based on 110 tagged and recaptured animals as :

I(t} = (l(max})(1-el-Klt-tIOIll), r2 = , 0 .99 where I(t} = precaudal length at time t, l(max} maximum theoretical length = 317.65 em, K = growth constant = 0 .057, and t(O} = theoretical age at 0 length = -2.302 years.

Manire and Gruber (78) presented evidence that large, dart tags may cause a retardation tn growth of juvenile lemon sharks, and cautioned about utilizing growth data collected from tagged individuals.

First-year survivability for an unexploited stock of juvenile lemon sharks in Bimini, Bahamas has been calculated to be 39% (instantaneous mortality [Zl = 0.94)(80).

46 Adults: Maximum size is 3.4 m (2 26 33) but "rarely" reaches 284.5 cm (54). One animal reported by Bigelow and Schroeder (2) was 290 cm long and weighed 120 kg. A late maturing species which reportedly becomes mature in no less than 12 years (79). A slow growing and long-lived species attaining an age of at least 20 years (55), but may attain an age as great as 27 years [Gruber, 1981; cited in (15)].

FOOD & FEEDING

An opportunistic piscivore, w ith ·no apparent pattern of diel feeding, which consumes about 2 % of its body weight daily (16 90). Teleosts (primarily snappers and sparids) are the major food category of neonate and juvenile lemon sharks from the Florida Keys and Bimini, Bahamas, accounting for 76-80% of the diet (16) . Schmidt (83) found that fish (predominantly pinfish and Gulf toadfish) comprised 77.1 % by number, and 87.7% by volume of the diet of young sharks caught on shallow grass flats in Florida Bay. Nonteleosts constitute about 10% of the diet of young lemon sharks (89). Pink shrimp constituted 22.9% by number, and 12% by volume of all food items in young lemon sharks caught in Florida Bay (73). Crustaceans (pink shrimp and blue crabs) were somewhat less important in the diet of sharks from the Keys and Bahamas, making up 5.8-7.8% of the diet (16). Clark and von Schmidt (14) reported that lemon sharks from the west central coast of Florida fed mainly on catfishes, mullet, and octopods. Other authors have also reported that the diet is primarily bony fishes including catfish, jacks, eels, halfbeaks, grunts, mullet, croakers, and mojarras (2 11 1 5 18 37 54 91). Schmidt (83) found plant material in the stomachs of 11 % of the lemon sharks he examined,. and Wetherbee et al (89) reported that plant material accounts for 11 % of the stomach contents of lemon sharks. Also feeds on rays, crabs, shrimp, octopi, and carrion (11 14 15 1837 5491). Small sharks and sea birds have also been found in their stomachs (11 15).

Lemon sharks exhibit an ontogenetic change in feeding habits with the diet of juveniles restricted to animals associated with the shallow bays and flats where the young are found, and w ith elasmobranchs, lobsters and adult jacks found only in the larger sharks (16 89). Cortes (90) found that elasmobranchs made up about 7% of the diet of larger lemon sharks, and reported that the diet of lemon sharks became more diverse with age. Known to be cannibalistic (47 87 89). Small lemon sharks are preyed upon by other, larger sharks (54).

Lemon sharks have been attracted to artificially generated, pulsed low-frequency sounds (20-60 hertz) which approximated sounds made by a struggling 12 kg grouper (86). Banner (84 91) reported that they were also attracted to broad-based noise, recordings of prey species, and a live grunt struggling at the end of a fishing line. It was suggested that such sounds could be significant shark attractants, and could influence feeding behavior (85).

Lemon sharks feed in short bouts, followed by a longer period of digestion, with little or no feeding in the interim (89). Longval et al (75) identified an apparent 4-day feeding cycle in lemon sharks held under controlled laboratory conditions. Food intake rises gradually for 2-3 days, followed by a sharp drop in food intake (75). It has been suggested that after an animal becomes sated, it takes a few days for the appetite to become re-established (75 90). Cortes (90) found that, on average, lemon sharks feed actively for 10-11 hours then fast for the next 32 hours. The daily ration of young lemon sharks has been estimated to be between 1.56% and 2.16% of body weight (16). Juveniles held in the laboratory at 25°C and 32%0 salinity required approximately 24 hr to completely digest a meal of fish fillets equivalent to 2.7% of the sharks body weight (76). Young lemon sharks required 28.4 to 40.8 hrs to digest a meal consisting of large head or caudal sections of snappers or grunts equivalent to 2.7% body weight, when held under field conditions at 20-29 ° C (77) . Wetherbee and G_ruber (88) found that I~rger meals are digested at the same rate as smaller meals, but take longer to be eliminated from the digestive tract.

47 ECOLOGICAL INTERACTIONS & NOTES

Lemon sharks exhibit slow growth, are late maturing with low fecundity, and are, therefore, very susceptible to overfishing. Intense fishing pressure could have disastrous consequences on lemon shark populations (79).

Citations

2 Bigelow, H.B. and W .C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found. Mar. Res., Yale Univ. Part I: 576.

7 Briggs, J.C. 1958. A list of Florida fishes and their distribution. Bull. FI. State Mus., BioI. Ser. 2(8):223-318.

11 Castro, J.1. 1983. The sharks of North American waters. Texas A & M Univ. Press, College Station, TX.180p.

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15: 13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2.

16 Cortes, E. and S.H. Gruber. 1990. Diet, feeding habits and estimates of daily ration of young lemon sharks, Negaprion brevirostris. Copeia 1990:204-218.

17 Dodrill, J.W. 1977. A hook and line survey of the sharks found within five hundred meters of shore along Melbourne Beach, Brevard County, Florida. MS Thesis, Florida Inst. Tech., Melbourne. 304p.

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

20 Gruber, S.H. 1982. Role of the lemon shark, Negaprion brevirostris (Poey) as a predator in the tropical marine environment: a multidisciplinary study. Fla. Sci. 45(1 ):46-75.

21 Gruber, S.H., D.R. Nelson and J .F. Morrissey. 1988. Patterns of activity and space utilization of lemon sharks, Negaprion brevirostris, in a shallow Bahamian lagoon. Bull. Mar. Sci. 43(1 ):61-76.

24 Heller, J.H., V.Z. Pasternak, J.P. Ransom and M.S. Heller. 1963. A new reticuloendothelial system stimulating agent ('Restim') from shark livers. Nature 199:904-905.

26 Hoese, H.D. and R.H. Moore. 1977. Fishes of the Gulf of Mexico: Texas, Louisiana and adjacent waters. Texas A & M Univ. Press. College Station, TX. 327p.

33 Robins, C.R., G.C. Ray, J. Douglass and R. Freud. 1986. A field guide to Atlantic coast fishes of North America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co., Boston. 354p.

37 Snelson, F.F. and S.E. Williams. 1981. Notes on the occurrence, distribution and piology of elasmobranch fishes in the Indian River Lagoon system, Florida. Estuaries 4: 11 0-120.

48 43 Swift, C., RW. Yerger and P.R Parrish. 1977. Distribution and natural history of the fresh and brackish water fishes of the Ochlocknee River, Florida and Georgia. Bull. Tall Timbers Res. Sta. 20:1 -111.

54 Springer. S. 1950. Natural history notes on the lemon shark, Negaprion brevirostris. Tex. J. Sci. 2(3):349-359.

55 Brown, C.A. and S.H. Gruber. 1988. Age assessment of the lemon shark, Negaprion brevirostris, using tetracycline validated vertebral counts. Copeia 1988:747-753.

65 Gilmore, RG. 1977. Fishes of the Indian River Lagoon and adjacent waters, Florida. Bull. Fla. State Mus., BioI. Sci. 22(3): 1 01-118.

67 Robins, C.R., RM. Bailey, C.E. Bond, J.R Brooker, E.A. Lachner, RN. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. Amer. Fish. Soc., Spec. Pub. 20, 183p.

73 Schlernitzauer, D.A. and P.W. Gilbert. 1966. Placentation and associated aspects of gestation in the bonnethead shark $phyrna tiburo. J. Morph. 120:219-232.

75 Longval, M.J., R M. Warner, and S.H. Gruber. 1982. Cyclical patterns of food intake in the lemon shark Negaprion brevirostris under controlled conditions. Fla. Sci. 45(1 ):25-33.

76 Schurdak, M .E. and S.H. Gruber. 1989. Gastric evacuation of the lemon shark Negaprion brevirostris (Poey) under controlled-conditions. Exp. BioI. 48:77-82.

77 Cortes, E. and S.H. Gruber. 1992. Gastric evacuation in the young lemon shark, Negaprion brevirostris, under field conditions. Environ. BioI. Fish. 35:205-212.

78 Manire, C.A. and S.H. Gruber. 1991. Effect of M-type dart tags on field growth of juvenile lemon sharks. Trans. Amer. Fish. Soc. 120:776-780.

79 Gruber, S.H. and R G. Stout. 1983. Biological materials for the study of age and growth in a tropical marine elasmobranch, the lemon shark, Negaprion brevirostris (Poey). Pp. 193-205. In: E.D. Prince and L.M. Pulos, Eds. NOAA Tech. Rep. NMFS 8.

80 Manire, C.A. and S.H. Gruber. 1993. A preliminary estimate of natural mortality of age-O lemon sharks, Negaprion brevirostris. Pp. 65-71. In: S. Branstetter, Ed. NOAA Tech. Rep. NMFS 115.

81 Morrissey, J.F. and S.H. Gruber. 1993. Home range of juvenile lemon sharks, Negaprion brevirostris. Copeia 1993:425-434.

83 Schmidt, T.W. 1986. Food of young juvenile lemon sharks, Negaprion brevirostris (Poey), near Sand Key, western Florida Bay. Fla. Sci. 49:7-10.

84 Longley, W.H. and S.F. Hildebrand. 1941. Systematic catalogue of the fishes of Tortugas, Florida. Carnegie Inst. of Washington Pub. 535, Pap. Tortugas Lab. Vo1.34:331 p + plates.

85 Banner, A. 1968. Attraction of young lemon sharks, Negaprion brevirostris, by sound. Copeia 1968:871-872.

49 86 Nelson, D. R. and S. H. Gruber. 1963. Sharks: attraction by low-frequency sounds. Science 142(3594) :975-977.

87 Morrissey. J.F. and S.H. Gruber. 1993. Habitat selection by juvenile lemon sharks, Negaprion brevirostris. Environ. BioI. Fish . 38:311-319.

88 Wetherbee, B.M. and S.H. Gruber: 1990. The effects of ration level on food retention time in juvenile lemon sharks, Negaprion brevirostris. Environ. BioI. Fish. 29:59-65.

89 Wetherbee, B.M., S.H. Gruber and E. Cortes. 1990. Diet, feeding habits, digestion, and consumption in sharks, with special reference to the lemon shark, Negaprion brevirostris. In: Elasmobranchs as living resources. H.1. Pratt, Jr., S.H. Gruber, and T.Tan

90 Cortes, E. 1987. Diet, feeding habits, and daily ration of young lemon sharks, Negaprion brevirostris, and the effect of ration size on their growth and conversion efficiency. M.S. Thesis, Univ. Miami, Florida 146p.

91 Banner, A. 1972. Use of sound in predation by young lemon sharks, Negaprion brevirostris (Poey). Bull. Mar. Sci. 22:251-283.

50 SPECIES: Sphyrna tiburo COMMON NAME: Bonnethead shark

OTHER SCIENTIFIC NAMES Recently used: Sphyrna vespertina (39)

OTHER COMMON NAMES - bonnetnose (25 26)' shovel-nose shark (25 32), bonnet-headed (36)' bonnet shark, shovel head (2).

CLASSIFICATION (67) Phylum: Chordata Class: Elasmobranchiomorphi Order: Lamniformes Family: Sphyrnidae

VALUE

Commercial: No regular fishery exists (18) and of little economic value (2 11 73). Taken in small-scale fisheries with shrimp trawls, trammel nets, long lines, and hook-and-line (15 18). Occasionally marketed fresh, fresh frozen, or salted (2 15 18), and also processed into fishmeal (15).

Recreational: Will readily take a hook with nearly any bait. Commonly caught ftombridges (33) and said to be lively sport on light tackle (11).

Ecological: Sometimes a prey for other shark species (18); is considered harmless to man (73).

RANGE

Overall: Western Atlantic from Massachusetts (occasional) throughout the Caribbean to Brazil and northern Argentina, including Bermuda (rare) (11 15 18 26 33). Very abundant in the northeastern Gulf of Mexico, on the continental shelf of western Florida, and on the Campeche Bank (18). Absent from the islands except Cuba and the western Bahamas (15 33). In the eastern Pacific from southern California to Ecuador (2 11 15).

Within Study Area: Common throughout Florida waters in the spring and fall; absent in some Florida areas during the summer (7 15). Reported in large schools in the fall (15). Not taken by Snelson and Williams (37) within the Indian River Lagoon, but not uncommon on the ocean beaches of east-central Florida. Reported as uncommon in the Dry Tortugas by Longley and Hildebrand (84).

LIFE MODE

Nektonic, often. occurring in schools in shallow coastal waters of 10-25 m depth but found out to 80 m (18 26). Common in river estuaries and around coral reefs (18). Schools usually are made up of 3-15 individuals (11 15). but large schools containing as many as 700 individuals have been ·reported near Sarasota, FL (13). Seldom found alone (15). Active during both day and night (72).

51 HABITAT

Type: Common in inshore, coastal, continental and insular shelf waters (15). Found chiefly in shallow water close inshore and often in bays and estuaries at depths between 10 and 25 m (2 14 15 73). They occur from the surf zone to depths of at least 80 m (15). In Louisiana they are also found in the saltier bays (26). Adult females predominate in shallow water in the pupping season (15).

Substrate: Reported from both sand and muddy bottoms, and around coral reefs (11 18).

PHYSICAL/CHEMICAL

Temperature: At Cedar Key, Florida, collected at temperatures from 28.9° to 30.6°C (32), from 25° to 31°C in Charlotte Harbor, FL (48), and from 15.0° to 33.3°C off southwest Florida (MML/CSR database).

Salinity: Collected from 25.6 to 29%0 at Cedar Key (32), from 19.5 to 35.5%0 in Charlotte Harbor (48), and from 22.8 to 36.1 %0 off southwest Florida (MML/CSR database).

MOVEMENTS/MIGRATIONS

Commonly found as far north as New England in the summer, but they apparently migrate southward with decreasing water temperatures in the fall and winter (15). In Florida it is believed that there is a southern movement in winter or that there is a migration to deeper water in winter (11). A preponderance of females in samples collected in the Florida Keys between .January and March suggested that sexual segregation occurs during that part of the year (72). Adult females often predominate in shallow water during the pupping season (15). Myrberg and Gruber (72) found that larger sharks generally swam faster than smaller individuals, and reported straight-line swimming velocities ranging from less than 33 cm/sec to 50 cm/sec. Parsons (31) reported an average swimming velocity of 41 cm/sec.

REPRODUCTION

Mode: Fertilization is internal; viviparous, with a yolk-sac placenta (15 18 73). Schlernitzaur and Gilbert (73) provided a description of uterine changes during embryonic development.

Mating & parturition: Maturity is said to occur at a size between 107 and 122 cm (2), but in southwest Florida, Clark and von Schmidt (14) reported a mature female of 87 cm and stated that males mature at 76 cm and larger. Off Florida, mating may be concentrated in the spring and fall, or may occur year-round (15). Parturition has been reported during the third week in August in south Florida (72). Juveniles are most abundant from March through September off southwest Florida (MML/CSR database).

Reproductive capacity: Fecundity estimates range from 4 to 1 6 embryos per female (2 11 1 5 1 8 36 73 84). One study found females to have as many as 12 to 14 embryos or uterine eggs (14).

GROWTH & DEVELOPMENT

Juveniles/Adults: Size at birth ranges from 30 to 40 cm (11 15). Measurements obtained from well-

52 fed individuals 60-80 cm in length held in captivity in the Bahamas suggested a slow growth rate, particularly during the late spring and early summer months (72) . Males mature at sizes between 52 and 75 cm, and females mature at 84 cm or less (11 15). Maximum size has been reported as 150 cm (15 18 33). Bigelow and Schroeder (2) stated that "few grow longer than 5 feet" (152 cm).

FOOD & FEEDING

Diet is primarily crustaceans including crabs and shrimp (11 15 18 26 33 36 73). Two studies specifically mention blue crabs (1423). They are frequently caught by fishermen using shrimp for bait (14). Other food items include clams, octopus, isopods, and small fish (2 11 14 15 18 73 84).

Citations

2 Bigelow, H.B. and W.C. Schroeder. 1948. Fishes of the western North Atlantic. Mem. Sears Found . Mar. Res., Yale Univ. Part I: 576.

7 Briggs, J.C. 1958. A list of Florida fishes and their distribution. · Bull. Flo State Mus., BioI. Ser. 2(8):223-318.

11 Castro, J.1. 1983. The sharks of North American waters. Texas A & M Univ. Press, College Station, TX.180p.

13 Clark, E. 1963. Massive aggregations of large eagle rays and sharks in and near Sarasota, Ftorida. Zoologica 48(2):61-64.

14 Clark, E. and K. von Schmidt. 1965. Sharks of the central Gulf coast of Florida. Bull. Mar. Sci. 15:13-83.

15 Compagno, J.L. 1984. Sharks of the world. FAO Fisheries Synopsis No. 125, Vol. 4, Part 2 .

18 Fischer, W. [ED.]. 1978. FAO species identification sheets for fishery purposes. Western central Atlantic (Fishing area 31). Vols. 1-7, FAO, United Nations, Rome.

23 Gunter, G. 1945. Studies on marine fishes of Texas. Publ. Inst. Mar. Sci. 1 (1 ):1-190.

25 Hildebrand, S.F. and W.C. Schroeder. 1928. Fishes of Chesapeake Bay. Bull. US Bur. Fish . 43:1-366.

26 Hoese, H.D. and R.H. Moore. 1977. Fishes of the Gulf of Mexico: Texas, Louisiana and adjacent waters. Texas A & M Univ. Press. College Station, TX. 327p.

31 Parsons, G.R. 1990. Metabolism and swimming efficiency of the bonnethead shark Sphyrna tiburo. Mar. BioI. 104:363-367.

32 Reid, G.K., Jr. 1954. An ecological study of the Gulf of Mexico fishes in the vicinity of Cedar Key, Florida. Bull. Mar. Sci. Gulf & Caribb. 4(1):1-94.

33 Robins, C.R., G.C. Ray, J. Douglass and R. Freud. 1986. A field guide to Atlantic coast fishes of North America. Peterson Field Guide Ser. No. 32, Houghton Mifflin Co ., Boston. 354p.

53 36 Smith, H.R 1907. The fishes of North Carolina. NC Geol. and Econ. Surv. 2:454p.

37 Snelson, F.F. and S.E. Williams. 1981. Notes on the oc·currence, distribution and biology of elasmobranch fishes in the Indian River Lagoon system, Florida. Estuaries 4: 110-120.

39 Springer, S. 1940. The sex ratio and seasonal distribution of some Florida sharks. Copeia 1940: 188-194.

48 Wang, J.C.S. and E.C. Raney. 1971. Distribution and fluctuation in the fish fauna of the Charlotte Harbor estuary, Florida. Mote Marine Lab., Sarasota, FL 56p.

67 Robins, C.R, RM. Bailey, C.E. Bond, J .R Brooker, E.A. Lachner, RN. Lea, and W.B. Scott. 1991. Common and scientific names of fishes from the United States and Canada. Amer. Fish . Soc., Spec. Pub. 20, 183p.

72 Myrberg, A.A., Jr. and S.H. Gruber. 1974. The behavior of the bonnethead shark, Sphyrna tiburo. Copeia 1974:358-374.

73 Schlernitzauer, D.A. and P.W. Gilbert. 1966. Placentation and associated aspects of gestation in the bonnethead shark Sphyrna tiburo. J . Morph. 120:219-232.

74 Tanaka, S.K. 1973. Suction feeding by the nurse shark. Copeia 1973:606-608.

84 Longley, W.H. and S.F. Hildebrand. 1941. Systematic catalogue of the fishes of Tortugas, Florida. Carnegie Inst. of Washington Pub. 535, Pap . Tortugas Lab. Vo1.34:331 p + plates.

54 APPENDIX II:

Center for Shark Research at Mote Marine Laboratory, Sarasota, Florida

"CONSERVATION AND MANAGEMENT OF SHARK POPULATIONS IN THE GULF OF MEXICO AND CARIBBEAN REGION"

April 21-23, 1993

CONFERENCE REGISTRATION LIST

Doug Adams Jay Bradley Florida Marine Research Inst. Melbourne Field Laboratory 328 W. Hibiscus Blvd. -- Melbourne, FL 32901 Chris Brannon

Elena Amesbury University of Central Florida Dept. of Biology Steve Branstetter, Ph.D. Orlando, FL 32816 Gulf & South Atlantic Fisheries Develop. Fdn. Basil Arend 5401 W. Kennedy Blvd. #5401 FN Pine Key Tampa, FL 33609 6228 9th Ave. N. St. Petersburg, FL 33710 Brad Brown, Ph. D. NOAA/NMFS H. David Baldridge, Ph.D. SE Fisheries Science Center 75 Virginia Beach Dr. Miami, FL 33149

Ramon BonfIl Sanders Steve Brown RRAG, Imperial College FDNRlFlorida Marine 8 Prince's Gardens Research Institute London, SW7 INA, U.K. 100 8th Ave. SE St. Petersburg, FL 33701

Richard Bruno

55 George Burgess Victor Chang FLA Museum of Nat. History Trans Ocean, Inc. University of Florida P.O. Box 291237 Gainesville, FL 32611 Pt. Orange, FL 32129

James Busse Bill Chauvin Seafood Atlantic Shrimp World Inc. 4065 Tangelo Ave. 417 Eliza St. Cocoa, FL 32926 New Orleans, LA 70114

Gregor Cailliet, Ph.D. Eugenie Clark, Ph.D. Moss Landing Marine Labs Dept. of Zoology, Room 32041 P.O. Box 450 University of Maryland Moss Landing, GA 95039 College Park, MD 20742-4415

Sally Campen Jody Cline Japan Fisheries Assn. 1800 Birch Road -~ McLean, VA 22101 Tris Colket Jeff Carrier, Ph.D. Dept. of Biology Albion College Albion, MI 42924

Jack Casey NOANNMFSINEFSC/Narragansett Laboratory Enric Cortes, Ph.D. 28 Tarzwell Dr. Mote Marine Laboratory Narragansett, RI 02882-1199 1600 Thompson Parkway Sarasota, FL 34236 Jose Castillo Geniz Program Tiburon Jess Dick Instituto Nacional de la Pesca c/o DeHooker, Inc. C.P.06100 5928 N. Oceanshore Blvd. D.F., MEXICO Palm Coast, FL 32137

Jose Castro, Ph.D. Shawn Dick NOANNMFSISEFSC/Miami DeHooker, Inc. Laboratory 5928 N. Oceanshore Blvd. 75 Virginia Beach Dr. Palm Coast, FL 32137 Miami, FL 33149

56 Robert Ditton, Ph.D. Oscar Greene Dept.of Wildlife & Fisheries Atlantic Flying Fish, Inc. Texas A&M U niversityCollege . 712 Evans St. Station, TX 77843 Morehead City, NC 28557

Leslie Finkelstein Samuel Gruber, Ph. D. RSMASlBimini Biological Field Station/U niversity of Miami 9300 SW 99th St. Sonja Fordham Miami, FL 33176 Ctr. for Marine Conservation 1725 DeSales St. NW Brent Hall Washington, DC 20036 University of Tampa Box 879 James Francesconi Tampa, FL 33606 NC Div. of Marine Fisheries-Box 769 Richard Hardy Morehead City, NC 28557

Michael Friday Mote Marine Laboratory -Mark Harrison 1600 Thompson Parkway Harrison International Sarasota, FL 34236 1201 School Ave. Springfield, FL 32404 James Gelsleichter VA Institute of Marine· Science Alan Henningsen Gloucester Point, VA 23062 National Aquarium Pier 3, 501 E. Pratt St. Perry Gilbert, Ph. D. Baltimore, MD 21202 Mote Marine Laboratory 1600 Thompson Parkway Colin Higgs Sarasota, FL 34236 Dept. of Fisheries Nassau, BAHAMAS Grant Gilmore, Ph.D. Harbor Branch Oceanographic Hays Hill Institution Harrison International 5600 Old Dixie Hwy. 1201 School Ave. Ft. Pierce, FL 34946 Springfield, FL 32404

M/M Marshall Gilmore John Hoey, Ph.D. Earth Kids Organization National Fisheries Institute P.O. Box 3847 1525 Wilson Blvd. #500 Salem, OR 97302 Arlington, VA 22209

57 Thomas Hoff, Ph.D. Nancy Kohler, Ph.D. Mid-Atl. Fishery Mgmt. Council NOAA/NMFS 300 S. New Street, #2115 28 Tarzwell Dr. Dover, DE 19901 Narragansett, RI 02882-1199

Michael Horvat Brian Lane Fla. Institute of Technology University of Central Florida 1680 Sunnybrook Lane #J205 Dept. of Biology Palm Bay, FL 32905 Orlando, FL 32816

Gordon Hubbell, D.V.M. Amy Lilly University of Tampa Box 879 Tampa, FL 33606 Rusty Hudson Directed Shark Fishery Assn. Carl Luer, Ph.D. P.O. Box 291358 Mote Marine Laboratory Pt. Orange, FL 32129 1600 Thompson Parkway Sarasota, FL 34236 Robert Hueter, Ph.D. Mote Marine Laboratory Tony Mak "1600 Thompson Parkway Sarasota, FL 34236

Christopher Jensen Charles Manire, D.V.M. Inst. of Marine Sciences Mote Marine Laboratory University of North Carolina 1600 Thompson Parkway 3431 Arendell St. Sarasota, FL 34236 Morehead City, NC 28557 John Marks Michael Justen NOAA/NMFS Southeast Regional Office 9450 Koger Blvd. Fernando Marquez Farias St. Petersburg, FL 33702 Instituto Nac'l de la Pesca C.P. 06100, D.F., MEXICO Glenda Kelley LG.F.A. Jim Mathews 1301 E. Atlantic Blvd. Fisheries Mgmt. Subcommittee Pompano Beach, FL 33060 Ford House BUilding-Rm. H2-513 Washington, DC 20515 Albert King ~ Joe McBride

58 Richard McHugh, Ph.D. Raul Marin Osorno Ctr. Econ. & Mgmt. Res. U niversidad Veracruzanal University of South Florida Aquario de Veracruz 4202 E. Fowler Ave. BSN3403 Veracruz, MEXICO Tampa, FL 33620-5500 Michael Parrack, Ph.D. Mike Mitchell NOAA/NMFS FLA Marine Research Inst. SE Fisheries Science Center Melbourne Field Laboratory 75 Virginia Beach Dr. 328 W. Hibiscus Blvd. Miami, FL 33149 Melbourne, FL 32901 Glen Parsons, Ph.D. Phil Motta, Ph.D. Dept. of Biology LIF 139, Dept. of Biology Univ. of Mississippi University of South Florida University City, MS 38677 Tampa, FL 33620 Carl Paulsen Tom Murray NatioJ1al Coalition for Seafood Producers Marine Conservation & Consumers Organization 510 1 Paulsen Street 1507 Newberger Road Savannah, GA 31405 Lutz, FL 33549 Dean Pilling Frank Murru Oceanus International Sea World of Florida . 18 SE Fourth Street 7007 Sea World Drive Boca Raton, FL 33432 Orlando, FL 32821 Oliver Putz Jack Musick, Ph.D. Harbor Branch Oceanographic VA Inst. of Marine Science Institution Gloucester Pt. , VA 23062 5600 Old Dixie Hwy. Ft. Pierce, FL 34946 Lisa Natanson, Ph.D. NOAAfNMFS Bets Rasmussen, Ph.D. 28 Tarzwell Dr. Oregon Graduate Institute Narragansett, RI 02882-1199 Beaverton, OR 97006

Russell Nelson, Ph.D. Maria Concepcion FLA Marine Fisheries Comm. Rodriguez de la Cruz 2540 Executive Ctr Cir. ·W.-106 Instituto Nacional de la Pesca Tallahassee, FL 32301 C.P. 061OO D.F., Mexico

59 Yvonne Sadovy Ron Schmied Caribbean Fishery Management NOAA/NMFS Council Southeast Regional Office San Juan, PUERTO RICO 9450 Koger Blvd. St. Petersburg, FL 33702 Carl Safina, Ph.D. National Audubon Society Frank Schwartz, Ph.D. 306 South Bay Ave. Inst. of Marine Sciences Islip, NY 11751 University of North Carolina 3431 Arendell St. Tony Salvo Morehead City, NC 28557

Steve Sidman U niv. of Central Florida James Sanchez Dept. of Biology Orlando, FL 32816

Frank Snelson, Ph.D. Eric Sander University of Central Florida F/V Marsea Dept. of Biology 882 Valencia Rd. Orlando, FL 32816 S. Daytona, FL 32119 Bob Spaeth Kim Sander Southern Offshore Fishing Assn. FLA Institute of Technology 13417 Gulf Lane Box 5267 Madeira Beach, FL 33708 Melbourne, FL 32901-6988 Bruce Stiller Norman Sander clo F N Marsea 882 Valencia Road S. Daytona, FL 32119 Adam Summers LIF 139, Dept. of Biology Richard Schaefer University of South Florida· NOAAlNMFSIOff. of Fisheries Tampa, FL 33620 Conservation & Management 1335 East-West Hwy. Raymond Swindle Silver Spring, MD 20910 DeHooker, Inc. 5928 N. Oceanshore Blvd. Douglas Scheidt Palm Coast, FL 32137 Harbor Branch Oceanographic Institution Wayne Swingle 5600 Old Dixie Hwy. GOM Fishery Mgmt. Council Ft. Pierce, FL 34946 5401 W. Kennedy Blvd. Tampa, FL 33609

60 Stephen & Deborah Brent Winner Thorsteinsson FDNRlFlorida Marine Research Institute 100 8th Ave. SE St. Petersburg, FL 33701 Lee Trent, Ph. D. NOANNMFS Panama City Laboratory 2422 Magnolia Dr. Panama City Beach, FL 32408

Tim Tricas, Ph.D. Dept. of BioSciences FLA Institute of Technology 150 W. University Blvd. Melbourne, FL 32901

John Tyminski Mote Marine Laboratory 1600 Thompson Parkway Sarasota, FL 34236

Glenn Ulrich SC Wildlife & Marine Resource Department P.O. Box 2559 Charleston, SC 29472

Rafael Velez Marin Instituto Nac'l de la Pesca Manzanillo, Colima, MEXICO

Jeff Weisner

David & Vicki Whiting US EPA Laboratory 1 Sab ine Island Dr. Gulf Breeze, FL 32561

Cheryl Wilga LIF 139, Dept. of Biology University of South Florida Tampa, FL 33620

61 APPENDIX III:

Center for Shark Research at Mote Marine Laboratory, Sarasota, Florida

"CONSERVATION AND MANAGEMENT OF SHARK POPULATIONS IN THE GULF OF MEXICO AND CARIBBEAN REGION"

April 21-23, 1993

CONFERENCE AGENDA

Wednesday, April 21

4:00 PM REGISTRATIONIMML DIRECTOR'S WELCOME & LAB TOURS Martin-Selby Education Center (MSEC), Mote Marine Laboratory Kumar Mahadevan, Executive Director, Mote Marine Laboratory Robert Hueter, Director, MML Center for Shark Research 5 :30 PM SOCIAL MIXER: Mote Marine Aquarium

Thursday, April 22 8:00 AM CONTINENTAL BREAKFAST: MSEC 8:30 AM WELCOME/OVERVIEW: Sharks as a Resource Robert Hueter, Center for Shark Research, MML

SESSION I: SHARK BIOLOGY Chair: Jeffrey Carrier, Department of Biology, Albion College 8:45 AM Life History Patterns & Reproduction Jose Castro, Southeast Fisheries Science Center, NOAA/National Marine Fisheries Service 9:00 AM Age, Growth & Demography Gregor Cailliet, Moss Landing Marine Laboratories 9: 15 AM Distribution & Migration John Casey, Narragansett Laboratory, NOAAlNational Marine Fisheries Service 9:30 AM Recruitment & Mortality Thomas Hoff, Mid-Atlantic Fishery Management Council 9:45 AM Fishery-Independent Population Studies Jack Musick, Virginia Institute of Marine Science 10:00 AM Panel Q&A 10:15 AM COFFEE BREAK

62 SESSION IT: MEXICAN SHARK RESEARCH & FISHERIES Chair: Enric Cortes, Center for Shark Research, MML 10:30 AM History of the Mexican Gulf Fishery Jose Castillo Geniz and Fernando Marquez Farias, Programa Tibur6n, Instituto Nacional de la Pesca 10:45 AM Sharks of Veracruz and Tamaulipas Raul Marin Osorno, Universidad VeracruzanalAquario de Veracruz 11 :00 AM Fishery Simulation Models for Characterizing Shark Fisheries Ram6n BonfIl Sanders, Renewable Resources Assessment Group, Imperial College of Science, Technology & Medicine 11: 15 AM Colima (Pacific) Pelagic Longline Fishery Rafael Velez Marin, David Mendizabal y Oriza, Javier Valdez, Fernando Marquez Farias and Gildardo Macias Salazar, Centro Regional de Investigaciones Pesqueras de Manzanillo, Instituto Nacional de la Pesca 11 :30 AM Panel Q&A 12:00 PM LUNCH: MML Chickee 1:00 PM · SPECIAL PRESENTATION: The Splendor of Sharks--A Personal View Eugenie Clark, Department of Zoology, University of Maryland Introduction by Perry Gilbert, MML/Cornell University

SESSION ill: U.S. COMMERCIAL SHARK FISHERIES - FISHING OPERATIONS Chair: Shawn Dick, DeHooker Inc. 1:30 PM Historical Overview of the Southeast Fishery Chris Brannon, Gulf Star Seafood 1:45 PM Longlining Operations in the South Atlantic Eric Sander, F IV Marsea 2:00 PM Longlining Operations in the Gulf Basil Arend, F N Pine Key 2:15 PM Gillnetting Operations off Florida Bruce Stiller, Shark Gillnetting Fleet Operator 2:30 PM PaneIQ&A. 2:45 PM COFFEE BREAK

SESSION IV: U.S. COMMERCIAL SHARK FISHERIES - FISHING INDUSTRY Chair: Thomas Murray, Seafood Producers & Consumers Organization 3:00 PM Commercial Directed Industry in Florida Russell Hudson, Directed Shark Fishery Assoc.lTransOcean Inc. 3: 15 PM Fin Markets & Distribution Dean Pilling, Oceanus International

63 3:30 PM Socioeconomics of Commercial Fishery in the Gulf Richard McHugh, Center for Economics & Management Research, University of South Florida 3:45 PM Commercial Industry, Research & Management John Hoey, National Fisheries Institute 4:00 PM Panel Q&A

SESSION V: U.S. RECREATIONAL SHARK FISHERIES Chair: Gordon Hubbell, Jaws International 4: 15 PM Shark Tournament Activity in Florida Robert Hueter, Center for Shark Research, MML 4:30 PM Socioeconomics of Recreational Fishery in the Gulf Robert Ditton, Department of Wildlife & Fisheries Science, Texas A&M University 4:45 PM Reducing Angler Impacts on Shark Resources Ronald Schmied, Southeast Regional Office, NOAA/National Marine Fisheries Service 5 :00 PM Panel Q&A

5:15 PM ADJOURN

7:30 PM BANQUET DINNER: MSEC

Friday, April 23 8:15 AM CONTINENTAL BREAKFAST: MSEC

SESSION VI: EDUCATION & CONSERVATION Chair: Steven Branstetter, Gulf & S. Atl. Fish. Development Foundation 8:45 AM Educating the Public about Sharks Frank Murru, Sea World of Florida 9:00 AM C;onservation Techniques in Fishing Operations Shawn Dick, DeHooker Inc. 9: 15 AM Role oj Conservation in Fisheries Management Carl Saf"IDa, National Audubon Society/Mid-Atlantic Fishery Management Council 9: 30 AM Conservationist Agenda Jor Sharks Sonja Fordham, Center for Marine Conservation 9:45 AM mCN Conservation Action Plan for Sharks Samuel Gruber, University of Miami/RSMAS 10:00 AM Panel Q&A

10:15 AM COFFEE BREAK

64 SESSION Vll: U.S. REGIONAL SHARK FISHERIES MANAGEMENT Chair: Grant Gilmore, Harbor Branch Oceanographic Institution 10:30 AM Florida Fisheries Management Russell Nelson, Florida Marine Fisheries Commission 10:45 AM Gulf-wide Regional Management Wayne Swingle, Gulf of Mexico Fishery Management Council 11:00 AM North Carolina Fisheries and Management James Francesconi, North Carolina Division of Marine Fisheries 11: 15 AM Panel Q&A

11:30 AM SPECIAL PRESENTATION: Sharks as a Resource for Biomedical Research and Development Carl Luer, Biomedical Research Program, MML

12:00 PM LUNCH: MML Chickee

SESSION VllI: U.S. FEDERAL SHARK FISHERIES MANAGEMENT Chair: Thomas Hoff, Mid-Atlantic Fishery Management Council 1:00 PM Data CoUection & Stock Assessment Michael Parrack, Southeast Fisheries Science Center, NOAA/National Marine Fisheries Service 1:30 PM Development & Implementation of the Atlantic FMP Richard Schaefer, NOAA/National Marine Fisheries Service 1:45 PM International Research & Management Issues Bradford Brown, Southeast Fisheries Science Center, NOAA/National Marine Fisheries Service 2:00 PM Panel Q&A

SESSION IX: CONFERENCE WORKSHOP 2:20 PM WORKSHOP COMMITTEE INSTRUCTIONS 2:30 PM JOINT SESSIONS -- Committee Deliberations 3:30 PM CONFERENCE RECOMMENDATIONS I: Research Rapporteur: Gregor Cailliet 4:00 PM CONF. RECOMMENDATIONS II: Fisheries & Management Rapporteur: Glenn Ulrich 4:30 PM CONF. RECOMMENDATIONS III: Education & Communication Rapporteur: Ronald Schmied 5:00 PM CONFERENCE EXECUTIVE SUMMARY

5:15 PM ADJOURN MEETING

65