South Carolina Sea Grant Consortium         PROJECT SUMMARY

Date:

June 1,2006

Title:	Use of Archival pop-off satellite tags to study cobia in Port Royal Sound , SC and dolphinfish present off the East Coast.
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:	None
Classification Number:
Keywords:
Parent Projects:	None

Objectives:

1. Deploy four pop-off archival satellite tags in cobia captured in or adjacent to Port Royal Sound.  2. Deploy six similar tags in dolphinfish captured in the South Atlantic Bight. 3. Develop a water temperature selection profile for each species utilizing time-at-temperature as recorded by the archival tags.  4. Analyze vertical movements in the water column for behavioral patterns using time-at-depth as recorded by the archival tags. 5. Attempt to identify near-shore waters utilized by cobia using depth and temperature records. 6. Attempt to document long distance movements using the satellite tag geo-positioning system.

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.      Working in conjunction with the Hilton Head Island Sports Fishing Club, the CSS biologist will implant the satellite tag in each cobia. Cobia will be obtained from the general fishing public during a highly promoted fishing event. Anglers will be issued a $300 check as a reward for donating their fish. The HHRF will be responsible for promoting the tagging event to generate interest among local anglers. If all tags are not deployed during the tournament, then tagging will be attempted using charter boats to capture the fish. Microwave Telemetry, Inc. model PTT-100 satellite tags [3 (three) provided by the SC DNR and 1 (one) by the Hilton Head Reef Foundation] will be programmed to record physical water conditions for 30 days (1 tags) or 90 days (3 tags). The constant pressure early release software program will be disabled in the tags.     Recreational anglers who have experience in tagging dolphin will be utilized to implant the six satellite tags programmed to record for 30 days. Selected anglers will be carefully instructed in the proper procedure for satellite tag deployment. An attempt will be made to deploy two tags each off south Florida/Florida Straits, South Carolina and North Carolina . 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.  Cobia vertical movement behavior will be compared to tidal cycles for possible correlations. Behavior of the dolphin tagged in the three geographical areas will be analyzed for temporal and spatial differences.

Rationale:

This project will follow-up on a study initiated in 2005 to assess the ability of archival pop-off satellite tags to provide information on the behavior of cobia and dolphinfish. It will examine the tags ability to provide information into their vertical water column movement behavior as well as identifying thermal preferences.  It will assess the instruments ability to document coastal and offshore depths utilized by each species. Data from dolphinfish will provide some of the first information defining the open water habitat utilized by the species which is of pressing concern to fisheries managers.  The study also has the potential to document spawning behavior of cobia as well as long distance movements for both species.  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 important marine fish.      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 appears to migrate northward along the east coast during spring. However, relatively little is else is known about the movements of cobia and only recently has information on dolphin movements started to be obtained. This is the first study to utilize satellite tags on cobia off the US Atlantic seaboard and the first 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 are rare and only link the release site to the recovery site by a straight line, this work could provide data on the value of satellite tags in examining coastal movements and behavioral patterns never before examined.     The initial attempt to carry out this study in 2005 resulted in one specimen of each species being tagged.  The cobia was tracked for five days before the tag prematurely released itself from the fish due to software problems. The dolphinfish was monitored for 10 days before the tag mysteriously surfaced.  Data collected by the instruments showed good promise for these devices to provide valuable information in to the life and behavior of these valuable gamefish.  Only one other pilot study to assess archival pop-off satellite tag use on cobia is known.  This study was conducted by the University of Southern Mississippi . USM's study is different in that it focused on monitoring cobia in the offshore waters of the Gulf of Mexico .  This project will attempt to determine if these archival remote sensing devices can ultimately provide real-time data on the water utilized by these fish.     Cobia over 15kg (33 pounds) occur singularly or in small groups while large dolphin, over 12kg (26 pounds), tend to be loners.  Due to the large size of the instrument to be attached, only the larger specimens will qualify for tagging. Capturing live large cobia or dolphinfish requires experienced fishermen using the appropriate boats and gear. Because of the low catch rate of large fish, 1 fish per 3 to 5 boat-days, a large amount of fishing effort will be required to secure the needed specimens. The initial attempt to conduct this study demonstrated that it is not economically feasible for research biologists to attempt to catch the necessary specimens. Therefore, the practical and cost-effective approach will be to enlist the aid of interested recreational fishermen to accomplish this work by giving them a incentive for donating fish or deploying a satellite tag. The cobia tagging will be achieved by advertising this project among recreational fishermen who fish in the Broad River , notifying them that a $300 reward will be paid anglers who donate their large, live, healthy cobia during a specific weekend in May 2006 and subsequent periods if necessary.  Tags intended for use on dolphinfish will be distributed to anglers who have either already deployed satellite tags or who have demonstrated their ability to successfully tag the species.

Anticipated Accomplishments/Benefits:

This project will provide some of the first long-term continuous information on the behavior of cobia and dolphin during their spring/summer movements and migration along the US East Coast.  It will provide information into their vertical water column usage as well as identifying thermal preferences.  Data gathered by this project will assist in identifying essential habitat for the species which is a stated priority by the South Atlantic Fisheries Management Council (agency responsible for cobia and dolphin management).  The study also has the potential to document long distance movements for both species as well spawning periods for cobia.  Additionally, this project will serve to assess basic elements in the development of research projects employing a cooperative approach with consumer groups. Two reports will be generated by this project.  The first will be a technical analysis of the findings that will be distributed to SC Sea Grant, SC DNR, and the SAFMC.  The second report will be prepared as a non-technical summary of the work and findings intended for the general public.

 
BUDGET JUSTIFICATION

Project Title:  Use of archival pop-off satellite tags to study cobia in Port Royal Sound and dolphinfish present off the East Coast.

  Note:  The most costly item required to complete this research, ten archival pop-off satellite tags ($40,000), has already been purchased jointly by the SC DNR and the Hilton Head Reef Foundation and is not included in the cost of this project.

Budget Item(s):

Publication Costs: $1,000

This item is to cover the cost of producing 200 copies of the technical report on the findings of the study along with as many copies of a brief educational report on the project as funds allow.

Angler Incentive Awards: $2,400

Incentive awards of $300 for qualifying cobia will be paid to 4 anglers. An award of $200 will be paid to 6 anglers for qualifying dolphin.  The large size of the tag requires them to be attached to only the top 1% of dolphin and cobia normally caught.  Both fish are extremely popular as food fish and subsequently requires a substantial reward.

ARGOS Satellite System Use: $15,000

Tags are designed to automatically download data for up to 45 days after surfacing via the ARGOS network.  Most tags transmit data for 30 days or less at an average cost of $1,500 per tag. 

Cooperative Science Services, LLC Contract: $12,000 (2.5 man-months)

Job	Time Required
1. Develop full project proposal	4%
2. Prepare necessary project reports required by Sea Grant	5%
3. Prepare and provide necessary supplies for tag deployment	5%
4. Provide photographic documentation as opportunity presents	0.5%
5. Oversee tag deployments (includes travel and shipping costs)	20%
6. Collate and prepare raw data for analysis	15%
7. Identify and collate external thermal ocean and estuarine data	6%
8. Discuss progress of the study with NOAA fishery scientists conducting work on these species and with the SAFMC responsible for their management	4%
9. Conduct data analysis providing needed computer and software equipment	16%
10. Prepare and publish project completion report	20%
11. Provide copies of data files to SC Sea Grant and to the SC DNR	1%
12. Prepare educational report	3.5%