Title:

      Use of Microwave Telemetry X-PSAT tags to monitor behavior of cobia and dolphinfish.

Please Check One:

x Full Proposal

 Seed/Development Proposal

Principal Investigator:

       David Harter

Affiliation(s):

      Board Member, Hilton Head Reef Foundation

Associate Investigator:

      Donald L. Hammond

Affiliation(s):

      Owner, Cooperative Science Services, LLC

Related Projects:

      2006 SCSGC - R60A

Classification Number:

Keywords:

Parent Projects:

      None

Objectives:

Tasks and Methodology:

      Hilton Head Reef Foundation (HHRF) will contract with Cooperative Science Services, LLC of Charleston, SC to conduct the tagging, data analysis, proposal development, report preparation and publication.

    This study focuses on spring fisheries that necessitate the actual deployment of the monitoring instruments during the spring of 2008. Using instruments that record for up to180 days automatically requires the program be extended beyond the grant end date set by Sea Grant. The principles in this study will aggressively seek the funding for the purchase of additional satellite tags, tagging rewards and other expenses from the private sector. Recreational fishing clubs and companies in the recreational fishing industry will be contacted seeking the sponsorship of a satellite tag to go on a dolphin or a cobia. Private sponsors will be able to decide in what geographical region the tag will be deployed if they also donate the offshore fishing trip that captures the proper specimen for tagging.

    The new X-PTT tag is half the size of the instrument used in the previous study, R60A. This miniaturization will allow much smaller, younger fish to be utilized. Monitoring different size classes will help evaluate if species behavior varies with size class. This also makes it easier to acquire an appropriate size specimen for tagging.

    Working in conjunction with the Hilton Head Island Sports Fishing Club and the Beaufort Sport Fishing and Diving Club, the CSS biologist will implant the satellite tag in each cobia. Cobia will be obtained from the general fishing public. Anglers will be issued a $300 check as a reward for donating their fish. Microwave Telemetry, Inc. model X-PTT satellite tags will be programmed to record physical water conditions and geo-location for 180 days. The constant pressure early release software program will be disabled in the tags placed on cobia.

    Program biologists along with recreational anglers who have experience in tagging dolphin will be utilized to implant the satellite tags that will be programmed to record for 180 days. Selected anglers will be carefully instructed in the proper procedure for satellite tag deployment. A minimum of three tags will be deployed off South Carolina with additional tags being deployed along the South and Mid Atlantic Bights as they become available. Fishermen will be paid a $200 reward for the successful deployment of each tag.

    Data for each species will be analyzed for diurnal and nocturnal behavior patterns in both water depth and temperature selection throughout the movement tracks.  Cobia vertical movement behavior will be compared to tidal and lunar cycles for possible correlations. Movement tracks for both species will be analyzed by geographical area for temporal and spatial differences.
 

Rationale:

     
   This project will follow-up on the Sea Grant funded study conducted in 2006 and 2007 to assess the ability of pop-off satellite archival tags to provide information on the behavior of cobia and dolphinfish. The initial study showed these instruments capable of providing quality information on their underwater behavior and environment. The proposed study will take the next step in studying the behavior of these two important species by examine the tag's ability to provide information as to their daily geo-location and their long-term vertical movement behavior as well as thermal preferences.  It will assess the instruments ability to document coastal and offshore depths utilized by each species. Successful tracking data will provide some of the first information defining the geographic range utilized by individual fish as opposed to the species as a whole.  The study also has the potential to generate data relating to spawning behavior of cobia. Additionally, the project will serve to join recreational fishermen in a collaborative effort with the SC Sea Grant Program and the SC DNR to gain needed information about two important marine species. 

    Dolphin and cobia are two of the most popular recreational species found off the US 's East and Gulf coasts. Both are fast growing species that appear to migrate northward along the east coast during spring. However, relatively little else is known about the movements of cobia and only recently has information on dolphin movements started to be acquired. This is the second study utilizing satellite tags on cobia off the US Atlantic seaboard and the second study ever to deploy them on dolphinfish.

    Recent studies using traditional dart tags have shown that cobia found in Port Royal Sound show strong site fidelity returning year after year. Port Royal Sound is one of only three east coast locals that have been identified as a spawning area for cobia. This significantly increases the importance in acquiring life history data on cobia that utilize the sound. This information could be useful in examining the effects of environmental cues on the species' daily and seasonal movements. Also, because recoveries of traditional tags only link the release site to the recovery site by a straight line and provide no information on the actual movement track, this work could provide data on the value of satellite tags in examining coastal movements and behavioral patterns never before documented.

    To date, the 2006 study has resulted in one cobia and three dolphin being tagged in the spring of 2006. The instrument on the cobia never contacted the satellite and is assumed dead. The three tags placed on dolphinfish tracked the fish for a total of 44 days.  Data collected by the instruments showed the fish using waters with temperatures ranging from 16.1oC to 30oC and used waters as deep as 124m. Data from the dolphin instruments also hint at a major night time feeding behavior that has never been considered prior to this study. Most of this information has never been acquired by any other research program.

Anticipated Accomplishments/Benefits: