When commercial fishermen began targeting dolphin, major concerns arose among fishermen along the entire Gulf and Atlantic coasts. Anglers voiced fears that without a management plan governing harvest, dolphin stocks could be overfished to the point of a major decline.
In 1998, the South Atlantic Fisheries Management Council (SAFMC) was directed to work with the Gulf and Caribbean Councils to develop a joint management plan for dolphin and wahoo. However, because of differences in the regional fisheries, little progress was made on a common plan. In 2002, the U.S. Department of Commerce approved development of a separate management plan by the SAFMC for the Atlantic coast, which resulted in the implementation of a management plan in 2004 for the Atlantic fisheries.
In developing the management plan for dolphin, managers found that there were many important facets of the dolphin's life history that were unknown. For example, little is known about the movements and migrations of the fish along the U.S.'s Atlantic and Gulf Coasts. The geographic range of the fish found in U.S. waters is also very important in developing an effective management plan. Managers must know if the stocks fished in U.S. waters are shared with other countries. Shared stocks occur when fish migrate into other nations’ waters, such as the Bahamas, or simply when they range beyond the 200-mile Exclusive Economic Zone (EEZ) controlled by the U.S.
When you combine the dolphinfish's aggressive feeding behavior, brilliant coloration, abundance and quality as a food-fish, it is easy to understand why it is considered one of the world's foremost game fish. In its annual surveys of subscribers, SaltWater Sportsman magazine consistently found dolphin to be the most popular offshore gamefish along the United States' Atlantic and Gulf coasts. Prior to the mid-1990s, dolphin were almost wholly harvested by recreational anglers and were the primary creel component sustaining an important offshore sports fishery.
A study conducted in 1991to track dolphin movements along the U.S. East Coast resulted in only 60 fish tagged and four tag recoveries, producing little viable information. Two attempts to use genetic material analysis to determine if multiple stocks existed in the Western North Atlantic yielded contradicting results as to whether differences did exist between fish found in other areas of the Northern Atlantic and those found off the U.S. East Coast.
Entering the new millennium, science still had little concrete information documenting the movements, occurrence and dispersal patterns for dolphinfish
Surprisingly, many recoveries of dolphin tagged off South Carolina showed very limited movements even after freedom periods as long as two months. This short-term residency was not exhibited in any other area off the U.S. East Coast. More than 80% of the recoveries of fish tagged off Florida occurred off Florida with only 12% of the Florida fish recoveries reported from waters north of Cape Hatteras, North Carolina. However, almost 38% of the recoveries of dolphin tagged off Georgia and South Carolina came from north of Cape Hatteras.
The SCDNR study revealed some amazing national and international movements. Several fish displayed northward movements of more than 1,000 miles along the U.S. East Coast. A recovery off Georgia established the first East Coast link with dolphin found off the south eastern Bahamas. Three other recoveries of fish tagged off the U.S. East Coast provided the first links with dolphin found in the eastern Atlantic south of the Azores Islands, off Antigua in the West Indies and off Belize/Mexico in the western Caribbean. These fish had traveled distances of 1,200 to 2,500 miles at a minimum.
CSS Dolphin Tagging Study Continues Research
The amazing information the SCDNR study generated inspired anglers to request that the research be continued. The Cooperative Science Services, LLC, a private fisheries research consulting company, was founded by Don Hammond to continue the dolphin research project. Conservation-minded fishermen were willing to donate the necessary funding to allow the study to continue as a private research program starting in 2006.
The private research effort was successful in its initial year with 1,500 dolphin tagged by more than 260 anglers fishing aboard 143 boats. The growth in tagging continued in 2007 reaching a record level of 2,485 dolphin reported tagged. However, the 2008 spike in the price of fuel and the slow-down in the economy which resulted in less free time from work for anglers to fish, took its toll on the tagging activity, with 1,350 fish marked that year. This brings the number of dolphin tagged in the seven years to 10,000 fish which involved more than 1,200 anglers and 432 different boats.
Reported recoveries resulting from the 2006 through 2008 tagging activity numbered 151 fish. Seven of these fish were recovered more than 1,000 miles from their release sites, including such places as Venezuela, Cuba and the south side of Puerto Rico. There were 13 other fish recaptured more than 700 miles from their release points clearly showing the highly migratory nature of these great game fish. The fastest rate of travel exhibited was 130 miles per day set by a dolphin recovered in 2004. From 2006 through 2008, 12 recaptured fish have averaged traveling more than 50 miles per day, straight-line distance. One fish showed that dolphin could travel almost the full length of the U.S. Atlantic territorial waters used by the species (Key West to Nantucket) in less than two months. The speed at which these fish can travel is impressive but the scope of their international dispersal from the U.S. East Coast challenges the multi-stock concept currently held by fishery managers for the species.
present off the US east coast. This data gap, coupled with strong vocal support for research on dolphinfish by constituent offshore fishermen, prompted the Marine Resources Division of the South Carolina Department of Natural Resources (SCDNR) to initiate a study on dolphin in 2002.
SC Department of Natural Resources Study
The SC dolphin tagging study initiated by the SCDNR was designed to address the travels of dolphin along U.S. shores in hope of beginning to define the movements and migrations. The study was highly successful in its four years of operation with more than 4,900 dolphin tagged and 116 tagged fish reported recaptured.
The project featured two tagging phases: one that offered a T-shirt as the reward for reporting a recapture and another that offered a $20 cash reward. This was conducted to assess differences in tag recovery reporting rates because of the reward. Yellow and orange external streamer dart tags were used to mark the fish. These tags possessed a unique serial number along with directions on how to report the tag recovery. The comparison of the reporting rate for a cash reward versus a T-shirt was inconclusive but anglers did indicate that the orange tag was more visible on the fish.
The 2002 – 05 study by the SCDNR confirmed for the first time that dolphin move from south to north in the spring along the U.S. East Coast. It showed that some of the dolphin found in the Straits of Florida in the early spring would travel as far north as New York and Massachusetts. The speed at which the fish traveled was highly variable. Recaptures of fish tagged in south Florida exhibited an average rate of travel that was twice as fast, 14.4 miles/day, as fish tagged off South Carolina, 6.5 miles/day.
To sign up to tag dolphinfish for this study, anglers should contact Don Hammond by email or telephone. To Report a Tag Recovery, use the convenient forms on our web pages by clicking the underlined link above or the link within the navigation bar at the top of this and other pages within this site.
® Copyright 2005-2014 Cooperative Science Services, LLC
High Technology Tags Employed
Research into the life and behavior of dolphin has included two projects funded primarily by South Carolina Sea Grant Consortium and the S.C. Department of Natural Resources that used the new, high-tech monitoring instruments known as pop-off satellite archival tags. These miniaturized computers record time-specific water temperature and depth at regular intervals along with the light intensity. Light intensity allows for the calculation of the daily geo-location of the fish. Each instrument is preprogrammed to record data for a specific period, 30 to 365 days. The fish does not have to be recovered to get the information. At the end of the scheduled period, the tag releases itself from its attachment to the fish, then floats to the surface where it downloads its data to the ARGOS satellite system, which transmits it back to research headquarters. These sophisticated instruments provide a look into natural behavior of dolphin never before attempted. But this amazing information comes at a price. Each tag costs $5,500 for the instrument, satellite time and data processing. However, even at this price it is the most cost-effective method to acquire this valuable information.
Conducted in cooperation with the Hilton Head Reef Foundation, the study has deployed eight of these marvels of technology on dolphin. Preliminary results from these instruments indicate that dolphin will use waters from 61oF to 88oF and will dive to depths below 400 feet. They also show that dolphin behave differently in different geographic regions and can spend as much as 30% of the daylight period at depths below 100 feet. Data from these tags are even building a case that identifies a feeding behavior used by dolphinfish never before considered, showing an unexpected bonus in the information these instruments can provide.
These technological wonders allow the Dolphinfish Research Program to collect essential habitat data for dolphinfish in ways never before possible. Plans call for more satellite tags to be deployed off the U.S. East Coast in the coming years. This will require additional funding and support from sports fishing organizations and industry.
Tax Deductible Donations
When it comes to government-financed research, dolphin have the curse of not being recognized as an overfished stock. With so many species of fish being overfished, there is not enough government money available to fund the work needed just on these declining stocks. Funding was not available from federal research programs because the fish has not been a priority and/or the study was not centered in the proper body of water. This leaves the study to rely on private donations to finance its operation.
The Hilton Head Reef Foundation, a non-profit organization, has volunteered to provide support for the CSS Dolphinfish Research Program. This registered 501 (c) (3) organization based in Hilton Head, South Carolina, will receive donations in support of the dolphin study making all such contributions tax-deductible. This organization also provides the opportunity for private foundations required by law to donate only to eleemosynary programs to contribute financial support. Donations should be sent to the address below with the checks made out to HH Reef Foundation/CSS Dolphin Study.
The major financial support for this study has come from private recreational fishermen and sports fishing organizations. Fishing clubs like the Central Florida Offshore Anglers have contributed as much as $7,700 in a single year while individual anglers have donated as much $5,000. Tagging participants have literally passed the hat at fishing club meetings to help raise money while families of avid dolphin anglers who have died have asked that friends make memorial donations to the Dolphinfish Research Program. This truly shows the deep and personal commitment anglers have to this research effort.
The primary goals of the proposed research are to establish the temporal and spatial occurrence, movement patterns and essential habitat of the common dolphinfish in the United States territorial waters, Gulf of Mexico, Western North Atlantic and Caribbean Sea. It is also intended to foster more research into the biology and behavior of dolphinfish. To accomplish this and other international goals, the project proposes to meet the following objectives:
1. Utilize as many experienced offshore fishermen as possible to capture, tag and record pertinent data on 1,000 dolphinfish in the western North Atlantic, Gulf of Mexico and Caribbean collectively each year.
2. Increase the number of vessels participating in tagging fish for the study in the Mid-Atlantic Bight, Gulf of Mexico, Caribbean Sea and Bahamas.
3. Initiate tagging studies in other parts of the world where significant populations of dolphinfish occur as angler interest allows.
4. Continue collaborative research projects with graduate schools at colleges and universities involved in marine research. Make the DRP data bases available for these studies.
5. Compile data to identify the origins/routes for dolphin entering U.S. territorial waters. Seek to develop and carry out dedicated tagging expeditions while building local tagging support in the Caribbean Islands and bordering Central American countries.
6. Continue to build on the temporal and spatial occurrence data base for dolphinfish along the U.S. East and Gulf Coasts. This will begin to identify the geographic area utilized by the species and recreational fishermen.
7. Continue to gather data on the occurrence of dolphinfish as it relates to Sargassum using observations from tagged fish records. Analyze the data to determine whether there is a correlation between the abundance of dolphin and the presence of Sargassum.
8. Continue to build on the temporal and spatial movement patterns using reported recaptures of tagged fish. In regions with large numbers of recaptures, compare movement data for variations in the speed of travel with other areas.
9. Examine fall and winter tag recoveries off Florida’s southeast coast to determine if a portion of the population regularly engages in a southerly fall movement and the southern limit of such movement.
10. Use satellite archival tags to monitor essential habitat and document movement routes of dolphinfish as funding allows. This study will attempt to track dolphin for as long as six months to identify their individual travel routes, temperature selection, and water column usage.
11. Continue an extensive public relations campaign to keep the media and public updated on the progress of the study. This will serve to keep the research project in front of the public. Strategies will include:
a. Maintain a Web site for the research project that will provide up-to-date information about the goals of the tagging study, detailed instructions on how to tag fish, an online method to report tagged fish recoveries, the life history of dolphin, how to identify the two species of dolphinfish, and their movements documented by this study. The Web site will also offer articles, papers and findings about or from the study.
b. Prepare and distribute at least 10 electronic newsletters during the year that report on the progress and findings of the study. Continue to build on the electronic mailing list of more than 1,900 fishermen, outdoor writers, fishery managers and other people interested in dolphinfish.
c. Present findings of the study in formal talks to scientific fisheries conferences, fishery management meetings, fishing organizations, and other fishery-related events/meetings.
d. Make information collected by the research program available to all fisheries management agencies actively involved in dolphinfish research/management and to scientific research programs actively studying dolphinfish.
Donald L. Hammond
Marine Fisheries Biologist
Cooperative Science Services, LLC
961 Anchor Rd.
Charleston, SC 29412-4902
Made possible by a grant from the Guy Harvey Ocean Foundation.