Incidental Catch of Non-Target Fish Species and Sea Turtles: Comparing Hawaii's Pelagic Longline Fishery Against Others

Progress Reports (PDF): FY 2008, FY 2007, SOEST-JIMAR report, FY 2006, FY 2004, FY 2003

Project Overview
The overall objective of the proposed project is to test whether a methodology patterned after work done by fisheries scientist M. A. Hall(1) for quantifying dolphin by-catch in the eastern Pacific purse seine tuna fishery can be adapted to Hawaii and other pelagic longline fisheries. The project team will analyze and present the by-catch impacts of the Hawaii pelagic longline fisheries for tuna and swordfish in a way that expresses by-catch as a function of the catch of primary target species. BPUE, or by-catch per unit effort, can be expressed in relationship to a unit of fishing effort or alternatively, per ton of primary target species caught and retained (Hall). The objective is to put the by-catch associated with the Hawaii pelagic longline fishery into perspective by using a comparable standard of ecological impacts to make comparisons with other fisheries for the same target species available in the U.S. seafood market.

Incidental catch impacts will also be calculated and presented in a similar fashion where mortalities (waste) of released fish are uncertain. Sea turtle takes (incidental catch) will also be calculated and presented as a ratio of the number of interactions per ton of primary target species retained. Finally, an estimate of the sea turtle mortalities will be calculated per ton of primary target species as a means of putting these impacts into perspective with other fisheries supplying the U.S. market with identical species of pelagic fish.

Specific objectives include:

1. Obtain the best available estimates of the targeted and non-targeted fish retained and discarded by the Hawaii pelagic longline fishery.
   
2. Obtain the best available estimates of sea turtle interactions associated with Hawaii pelagic longline fishery.
   
3. Develop the approach to calculating and standardizing the incidental catch and by-catch impact indices characterizing the catch of target species in the Hawaii pelagic longline fishery.
   
4. Develop a matrix of the selected incidental catch and by-catch impact indices for the Hawaii pelagic longline fishery that can be used to compare the impacts of various fisheries management scenarios and compare between fisheries.
   
5. Try to obtain fisheries data from a select group of distant pelagic longline fisheries needed to generate estimates of incidental catch and by-catch impact indices for comparison with Hawaii's pelagic longline fishery.
   
6. Prepare a draft document comparing Hawaii's multi-species pelagic fishery with other pelagic fisheries that tend to retain only target species (tuna, swordfish) and may also impact sea turtles.

⁽¹⁾ Hall, M.A., 1999. Estimating the ecological impacts of fisheries: What data are needed to estimate bycatches? FAO International Conference on Integrated Fisheries Monitoring, Sydney, Australia, February 1-5, 1999. pp. 175-184.

Year 1 funding for this project awarded in June 2002

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Dr. John Kaneko
Pacific Management Resources, Inc.
(PacMar, Inc.)
3615 Harding Ave., #408-409
Honolulu, Hawaii 96816 USA
Phone (808) 735-2602
FAX (808) 7354-2315
email: pacusa@pixi.com