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Hawaii Tuna Tagging Project Two (HTTP2)

See also Hawaii Regional Tuna Tagging Project,
Instrumented Buoys as Autonomous Observatories of Pelagic Ecosystems,
Trophic Ecology and Structure-Associated Aggregation Behavior in Bigeye and Yellowfin Tuna in Hawaiian Waters

Progress Reports: FY 2012, FY 2011, FY 2010, FY 2009

Background and Rationale
Tagging programs are widely recognized as important tools for understanding the population dynamics, dispersal patterns and fisheries interactions of fish populations (e.g., Bills and Sibert, 1997). For pelagic species in the Pacific, two large tag and recapture projects were carried out by the South Pacific Commission (SPC, now the Secretariat of the Pacific Community) in the 1970's and 80's to develop an understanding of the tuna resources of the western Pacific. The results of those studies became central to fisheries management in the region. In the face of changing fishing pressure and improved analytical techniques, the newly established Western and Central Pacific Fisheries Commission (WCPFC) has recognized the need to update these analyses and has initiated what is hoped will be a pan Pacific tuna tagging program (PTTP). The Hawaii-based tuna tagging project described herein will be considered as a sub-regional component of the broader SPC/WCPFC sponsored Pacific Tuna Tagging Program and will use common methodologies and arrangements are in place for integrated data sharing and analysis.

Previous tagging initiatives in Hawaii have been funded by the Pelagic Fisheries Research Program. These were primarily focused on issues of local importance but the results of these studies definitely had broader relevance. Two priorities were identified for these earlier studies; 1) the role of the Cross Seamount and its associated fishery in the dynamics of tuna fisheries in Hawaii and 2) the impact of anchored FADs on the biology and behavior of yellowfin and bigeye tuna. In response to these concerns, PFRP funded FAD-related research and the Hawaii Tuna Tagging Project (HTTP) that primarily focused on the yellowfin and bigeye populations associated with the Cross Seamount and the offshore weather buoys targeted by Hawaii fleets. The HTTP deployed over 15,000 conventional tags on bigeye and yellowfin tuna to address issues of movement between geographical areas and different fishery sectors and to derive life history parameters. The project was very effective in quantifying residence times of bigeye and yellowfin tuna on the seamount, exchange rates between major fishing grounds or fisheries and providing size-dependent estimates of natural and fishing mortality (Adam et al, 2003; Sibert et al., 2000; Holland et al., 1999). Similarly, PFRP funded FAD related research has elucidated important aspects of the biology of fish aggregations associated with these devices (Dagorn et al. 2007; Itano and Holland, 2000, inter-alia).

In the decade since the HTTP was concluded, local fisheries have changed. The seamount fishery has developed new methods and targets different species and sizes while privately set "bigeye FADs" have proliferated closer to shore. These and other developments in the domestic and expanding international fisheries have created a new set of potential user group conflicts and management concerns. In order to update movement and life history parameters of tuna in Hawaiian waters and to address current fishery issues in Hawaii (and the broader WCPO) we propose HTTP2. This time, more emphasis will be placed on coastal fisheries (although there will be an important seamount component) and skipjack tuna will be included in the tagging program.

Objectives
There are three principal objectives in the planned program. These have been designed to address management concerns of the Western Pacific Regional Fishery Management Council (WESPAC) and WCPFC.

Objective 1. Obtain estimates of growth rates, fishing mortality (F), 'natural' mortality (M) and movement (dispersal) parameters for yellowfin, bigeye and skipjack tuna in Hawaiian waters. This will be the first time that these parameters have been quantified for skipjack tuna in Hawaii. Amongst other things, these experiments will allow us to define the size of the ecosystem of "Hawaiian fish" and elucidate any connectivity with other regions of the Pacific. This component will include an emphasis in FAD-associated bigeye tuna. Privately deployed FADs (PFADs) have become an important aspect of the Hawaiian fishery and these FADs are specifically designed to exploit bigeye tuna - a species about which there is concern regarding overall population status. Tag and release of FAD-associated bigeye tuna will provide estimates of residence times, dispersal patterns and growth rates.

Objective 2. Document the FAD-associated behavior of skipjack tuna. Although skipjack tuna is the most common species found in association with FADs, no previous work in Hawaii has focused on their FAD associated behavior (either residence patterns or depth distribution). We will use pressure sensitive acoustic transmitters to monitor the residences patterns and vertical distribution of FAD-associated skipjack tuna. In order to place their behavior in perspective with other FAD associated species, acoustic tagging will aim to simultaneously tag skipjack and yellowfin tuna of similar sizes so that their behavior can be compared under similar oceanographic conditions.

Objective 3. Determine the diurnal vertical behavior of bigeye tuna associated with the Cross seamount. Seamounts play an extremely important role in the tuna fisheries of the world. In Hawaii, the Cross Seamount plays an important role in local fisheries and has received considerable attention in terms of its physical oceanography and fisheries biology (Holland and Grubbs, 2007; Holland et al, 1999). However, we still know little about how tuna exploit the forage resources at seamounts. Therefore, a component of HTTP2 will use acoustic telemetry to document the vertical behavior of bigeye tuna caught in association with Cross seamount. An additional benefit of this component will be to obtain residence duration data to compare with previous studies that used tag-and-recapture methodologies (Holland et al, 1999).

Methodology
General methodology. Two general methods will be used throughout the project; 1) mark-recapture experiments using "spaghetti tags" and, 2) passive acoustic tracking using ultrasonic pingers and appropriate receivers deployed in strategic locations. The mark-recapture component will use serially numbered, nylon tipped plastic "spaghetti tags" inserted into the dorsal musculature of individual fish. For experimental consistency, these will be of the same size and manufacture as in the original HTTP. These tags are recovered by fishermen and reported to the researchers via a dedicated phone number. We hope to tag between 10,000 and 15,000 animals over the course of the project. The passive sonic tracking component will involve surgical intraperitoneal implantation of small (9 X 15mm) sonic transmitters (69 kHz) into the various target species. These transmitters will be detected by acoustic receivers ("listening stations") attached to FAD moorings. Receivers will also by deployed on temporary bottom moorings on the Cross seamount and other topographic features. These receivers will be equipped with sonic release mechanisms and recovered at the end of the study. Both these techniques are widely used and have been part of several previous PFRP-funded projects.

Because HTTP2 is designed and implemented as a compatible sub-regional component of the broader-scale Pacific Tuna Tagging Program (PTTP), we have established protocols for data sharing between HTTP2 and PTTP so that maximum use can be made of the data acquired by the two projects.

Year 1 funding for this 2-year project to be available late 2008.

References

Adam, M.S., J. Sibert, D. Itano, and K. Holland. 2003. Dynamics of bigeye (Thunnus obesus) and yellowfin (T. albacares) tuna in Hawaii's pelagic fisheries: analysis of tagging data with a bulk transfer model incorporating size-specific attrition. Fish. Bull. 101:215-228.
Bills, P.J. and Sibert, J.R. 1997. Design of tag-recapture experiments for estimating yellowfin tuna stock dynamics, mortality, and fishery interactions. SOEST Publication 97-05, JIMAR Contribution 97-313, 80 pp.
Dagorn, L., K. N. Holland, D. G. Itano. 2007. Behavior of yellowfin (Thunnus albacares) and bigeye (T. obesus) tuna in a network of fish aggregating devices (FADs). Mar. Biol. DOI 10.1007/s00227-006-0511-1.
Itano, David G., and Kim N. Holland. 2000. Movement and vulnerability of bigeye (Thunnus obesus) and yellowfin tuna (T. albacares) in relation to FADs and natural aggregation points. Aquatic Living Res., 13 (4): 213-223.
Holland, K.N., P. Kleiber and S.M. Kajiura. 1999. Different residence times of bigeye and yellowfin tuna occurring in mixed aggregations over a seamount. Fish. Bull. 97:392-395.
• Sibert, J., K.N. Holland, and D.G. Itano. 2000. Exchange rates of yellowfin and bigeye tunas and fishery interaction between Cross seamount and near-shore FADs in Hawaii. Aquatic Living Res., 13 (4): 225-232.

 

Principal Investigators:

Dr. Kim Holland
Hawaii Institute of Marine Biology (HIMB)
University of Hawaii at Manoa
Coconut Island
P.O. Box 1346
Kaneohe, Hawaii 96744 USA
Phone (808) 236-7410/533-4110
FAX (808) 236-7443
email: kholland@hawaii.edu

 

Mr. David Itano
Pelagic Fisheries Research Program (PFRP)
University of Hawaii at Manoa
1000 Pope Road, MSB 312
Honolulu, Hawaii 96822 USA
Phone (808) 956-4108
FAX (808) 956-4104
email: dgi@hawaii.edu

 

Dr. Kevin Weng
Pelagic Fisheries Research Program (PFRP)
University of Hawaii at Manoa
1000 Pope Road, MSB 312
Honolulu, Hawaii 96822 USA
Phone (808) 956-6346
FAX (808) 956-4104
email: kweng@hawaii.edu

 

 

 

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This page updated January 31, 2013