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Hawaii Regional Tuna Tagging ProjectProgress Reports (PDF): FY 2002, FY 2001, FY 2000, FY 1999, FY 1998 (see below)Project Overview The Pelagic Fisheries Research Program (PFRP) of the University of Hawaii has funded two distinct, but closely related tuna tagging projects in Hawaii using conventional mark and recapture techniques. The Hawaii Seamount Tagging Project was designed to address aggregation and interaction issues specific to the Cross Seamount which is the site of a productive fishery for bigeye and yellowfin tuna in the Hawaii EEZ .1 A PFRP funded tag-recapture modeling project to design a tuna tagging experiment for Hawaii and a tuna tagging workshop held during 1997 provided the framework for the larger scale Hawaii Tuna Tagging Project (HTTP). The project began in March 1998 and will tag and release yellowfin and bigeye tuna throughout the Hawaii EEZ over a two year period. Based on the tag-recapture modeling project HTTP researchers plan for quarterly releases of 500 tags at three locations over a two-year period, a target of 6,000 tag releases per year (12,000 for the project). During 1998, after only ten months of field tagging, the HTTP had released 9,385 tuna (4,301 bigeye, 5,084 yellowfin), thus far exceeding the proposed annual release target. Overall recapture rates for the HTTP at the end of calendar year 1998 were 9.14%. The Hawaii Tuna Tagging Project will investigate movement patterns of yellowfin and bigeye tuna within the Hawaii EEZ and between fishing grounds and fisheries which will produce information on exploitation rates and interaction. Aggregation effects and differential vulnerability of tuna associated with seamounts and fish aggregation devices (FADs) will be investigated. The Hawaiian Island archipelago is geographically, and to some degree, biologically isolated from the Western and Eastern Tropical Pacific. The HTTP should produce information on long distance movement and interaction, stock structure and mixing rates of Pacific yellowfin and bigeye useful for management purposes. Results from the project will also contribute to what is known on the basic biology of the species, such as growth rates, longevity and mortality. Assistance from the international pelagic research community in obtaining accurate tag recapture data is requested. HTTP tags are 11 cm orange or 9cm yellow plastic dart tags inserted below the second dorsal fin. Green colored tags indicate OTC injected bigeye for which an accurate recapture date and the otoliths are required for age validation work. Researchers with the Seamount Tagging Project collaborated with the Inter-American Tropical Tuna Commission (IATTC) on an age validation study for bigeye tuna using standard oxy-tetracycline (OTC) mark and recapture techniques. See also:
1 Researchers for the Seamount Project collaborated with the Inter-American Tropical Tuna Commission (IATTC) on an age validation study for bigeye tuna using standard oxy-tetracycline (OTC) mark and recapture techniques.
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Principal Investigators: Dr. Kim
Holland |
Mr. David
Itano |
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Progress Report - June - December 1998
Submitted by: David G. ItanoReport period: to December 31, 1998
Summary:The project Principal Investigators received funding to begin this project in March 1998. Surplus tagging equipment and tag recapture rewards from the Seamount Tagging Project (NOAA/JIMAR #2064/2112) was inherited by the new Hawaii Tuna Tagging Project which allowed a rapid commencement of activities. A large scale publicity effort began as soon as the project started to notify local and international fisheries research and industry contacts on the project and tag reporting procedures. Articles have been published in popular journals, newsletters and on the World Wide Web to promote tag recapture reporting and project awareness. In addition, a television program broadcast throughout Hawaii documented the project methods and objectives. Three part-time field technicians have been trained and hired at major fishing ports to conduct tagging cruises and monitor and tag recapture and reward systems. Tagging success has been excellent in the offshore areas and near Midway Atoll. Additional tagging has taken place at inshore FADs of the main Hawaiian Islands and at many locations throughout the Northwest Hawaiian Islands.
Personnel and training:Three field technicians have been trained and recruited to the project based in Honolulu, west Maui, and the Kona area of the island of Hawaii. Their main duties are to conduct tagging cruises and gather tags and tag recapture data from fishermen. Honolulu (Kewalo Basin) and Kona (Honokohau Harbor) are the main ports for Hawaii based offshore handline, troll and longline fisheries. Lahaina, Kahului, and Maalaea Harbors (Maui) are key ports for small-scale troll and handline fishermen in the central Hawaiian Islands. Dependable technicians in all areas are critical to the success of the project as they can maintain a close contact with the fishermen to gather fishing catch/effort and tag recapture data. The data entry technician from the Seamount Tagging Project continued with this project. Main duties are to clean up, enter and summarize tag release and recapture data, and handle recapture rewards and publicity. The project PI oversees administration, trains project personnel, conducts tagging cruises, and writes promotional articles to publicize project activities and increase reporting levels.
Gear and equipment:The Hawaii Tuna Tagging Project (HTTP) inherited a stock of tags, tag applicators, data recorders and reward T-shirts from the Hawaii Seamount Tagging Project (NOAA/JIMAR # 2064/2112). Additional tags, tag holders, tagging mattresses and capture gear has been purchased to equip newly recruited personnel.
Activities:a. Publicity and rewardsAn extensive publicity campaign has been initiated that will continue throughout project period. On the international front, letters, posters and e-mail were sent to individuals in tuna research and industry throughout the Pacific and Indian Ocean region and to major fish processing and research facilities throughout the world. A positive response has been received from many regions stating cooperation in the return of tag recapture information. The tagging poster has been translated into Chinese and Japanese for distribution to distant water fleets. Within Hawaii, color posters explaining the project have been circulated throughout the state. Articles on the new tagging project have appeared in the Hawaii Fishing News and a newsletter of the Inter-American Tropical Tuna Commission. A television program, Pacific Adventures, detailed the HTTP field techniques and project objectives while filming an episode at Midway Atoll. Tag rewards have become very important to promote tag reporting from the local fishing industry. Colorful T-shirts, hats and insulated drink holders printed with the project logo have been produced and are given in exchange for recaptured tags and information. Cooperation has been excellent with the local fishing and fish-processing community and the reporting rate for this project is believed to be very high.
b. Tag release and recapturesA total of 4,301 bigeye and 5,084 yellowfin were tagged during 1998 for a total of 9,385 releases. In combination with the 4,859 tuna that were tagged during the Hawaii Seamount Tagging Project, a total of 14,244 yellowfin and bigeye have been tagged Hawaiian waters during recent years. The majority of tag releases have been made at the Cross Seamount and at offshore NOAA weather buoys. However, 1,061 yellowfin and bigeye have been tagged near Midway Atoll (the NW corner of Hawaiian archipelago). Tuna have also been tagged near Nihoa and Necker Islands, Maro Reef, Laysan Island, Northampton Seamounts, Lisianski Island, and Pearl and Hermes Reef. Other tagging activities concentrated on releasing fish on FADs near the main Hawaiian Islands. To date, recapture rates for the HTTP are at 9.14% (9.87% for yellowfin, 8.39% for bigeye). The majorith of recaptures are short-term; near or at the point of release. However, several recaptures of fish tagged at offshore locations have been recaptured on inshore FADs or fishing grounds, and there has been considerable movement documented between different Hawaii State FADs. |
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Table 1. Tag summary - 1998
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Tag Summary Jan. 1999
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Last release Jan. 9, 1999
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Hawaii Seamount |
Bigeye
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Bigeye %
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Yellowfin
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Yellowfin %
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Total
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Releases
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3400
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60.97%
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1459
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30.03%
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4859
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Recaptures
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202
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60.48%
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132
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39.52%
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334
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Recapture rate
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5.94%
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9.05%
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6.87%
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Hawaii Tuna
Tagging Project |
Bigeye
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Bigeye %
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Yellowfin
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Yellowfin%
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Total
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Releases
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4301
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45.83%
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5084
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54.17%
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9385
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Recaptures
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361
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42.07%
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497
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57.93%
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858
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Recapture rate
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8.39%
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9.78%
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9.14
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Grand Totals |
Bigeye
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Bigeye %
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Yellowfin
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Yellowfin %
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Total
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Releases
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7701
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54.06%
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6543
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45.94%
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14244
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Recaptures
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563
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47.23%
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629
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52.77%
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1192
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Recapture rate |
7.31%
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9.61%
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8.37%
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Collaboration:Reporting rates from the offshore handline and small scale troll fleet are very high. Recaptures from longline gear have been low but were noted to increase toward the end 1998 possibly due to the growth of smaller tagged fish that are now recruiting to longline fisheries. No recaptures have been made near Midway Atoll and only one fish tagged near Midway has been recovered (large yellowfin taken on longline gear southwest of Kauai). Only one international recapture has been reported to the project, which was a yellowfin tuna released on the Cross Seamount and recovered after six months at liberty near Baja Mexico. This fish was the only purse seine recapture to date. The National
Marine Fisheries Service began tagging medium-sized bigeye tuna with
archival tags during April 1998 with funding provided by the PFRP. Conventional
dart tags from the Hawaii Tuna Tagging Project were provided to the
NMFS to allow marking of fish implanted with archival devices to assist
with obtaining recaptures. During the first tagging cruise of their
program, 23 bigeye tuna 76 - 131 cm were tagged in this manner and released
off the Kona coast of the island of Hawaii. The NMFS will continue to
double their archival tagged fish with HTTP tags to benefit from the
extensive publicity and tag reporting system that is already in place.
These releases resulted in a single recapture to date which yielded
fascinating information on the behavior of bigeye tuna. A second NMFS
tagging cruise was conducted in January 1999 which resulted in 27 more
bigeye implanted with archival tags and double tagged with HTTP orange
plastic dart tags. |
Meetings and conferences: |
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The project PIs attended the 49th Tuna Conference at Lake Arrowhead, California (May 18-21) where they both made presentations on the Seamount Tagging Project and the Hawaii Tuna Tagging Project. A project summary was also presented at the South Pacific Commission, 11th Standing Committee on Tuna and Billfish and species working groups (May 30 - June 5 in Honolulu, Hawaii) and at the Pacific Bigeye Tuna Research Coordination Workshop (November 9-10, 1998 in Honolulu, Hawaii).
Future activitiesDuring the end of 1998, the HTTP began an ancillary tagging project that targeted small (20 - 40 cm) yellowfin and bigeye tuna found in aggregation to Hawaii State FADs. Juvenile tunas aggregate strongly to these FADs, and during the fall and winter months, very small fish are readily available and vulnerable to hook and line gear. Through a collaborative effort with the Hawaii FAD program, smaller sized tags (9 cm), tag applicators and tag recapture rewards were purchased and some preliminary tagging trips were conducted. Tagging small tunas on FADs will be a priority activity during the first quarter of 1999.
This page updated August 14, 2006 |