Modeling of the Tradeoff between Sea Turtle Take Reduction and Economic
Returns to the Hawaii Longline Fishery
As of January 2005, Dr. Minling Pan of the NMFS-PIFSC has taken over
as lead PI for this project)
Reports: FY 2008,
FY 2007, FY
2006, FY 2005
This proposal describes research to advance ecosystem-based fishery
management by updating previously published economic models for the
Hawaii-based longline fishery (HILLF) and by using the updated models
to estimate economic returns associated with either current or proposed
time/area closure policies. As such, this proposed work should be useful
to assess the benefits (i.e., reducing incidental takes of sea turtles)
and costs (i.e., fishers' income loss) of management policies.
of this project is to incorporate a time/area closure model (K-P model)
previously developed to estimate sea turtle takes (Kobayshi-Polovina,
2001a, 2001b) into a multilevel and multiobjective programming model
developed in an ongoing PFRP project (MMPM2).
This updated model will then be used to estimate economic returns and
incidental takes of sea turtles over space and time under existing and
potential regulatory policies. Ideally, this model should enable regulators
and fishers to develop policies that would direct fishing effort to
areas and times that will maximize economic return and minimize protected
objectives are to:
an integrated ecosystem database, combining with fishery technical
data (logbook and observer's data), market data, and cost-earnings/socioeconomic
the fishing vessel's behavior model of the MMPM2; and
the K-P model's method or more updated one to estimate incidental
turtle takes and kills into the MMPM2.
of data processors to generate updated parameters from various databases,
including the longline logbook data, the data collected by the Hawaii
Longline Observer Program, and auction data from United Fishing Agency
(UFA) and the State of Hawaii Division of Aquatic Resources (HDAR).
The data processor developed under the MMPM2 project can be reused
for this project.
the current economic model (MMPM2) by incorporating various fishers'
behavioral assumptions: No-Displacement, Displacement, Open Access,
and Discrete Fleet Dynamic Model.
Because of the contributions by the K-P model and other latest findings
regarding turtle takes, the ranges for the area and months of time/area
closure considered to reduce turtle takes are much narrower. Therefore,
a "spatial/temporal" sensitivity analysis will be conducted. The data
processors developed in MMPM2 will be used for this sensitivity analysis.
estimation of sea turtles incidental takes and their percent reduction.
Data collected by the Hawaii Longline Observer Program will be used
for this estimation.
The K-P model integrated the estimates of turtle takes and kills during
1994-1999 provided by McCracken (2000) using generalized additive
models (GAM). That is, the predicted takes of each sea turtle species
for each area and month based on the historical average level of effort
will be obtained and then adjusted to reflect changes in effort caused
by closure, other regulations, or season. The proposed work will follow
the same method as the K-P model in the first phase. The data collected
by the Hawaii Longline Observer Program of the NMFS will be used for
this estimation. As the project progresses, researchers will improve
the forecasts of turtle takes by incorporating recent findings and/or
other data sets.
develop decision support guidelines for policy making.
MMPM2 already has a mechanism to easily generate a "tradeoff frontier
" where net return is maximized given the expected turtles takes and
kills (Pan et al. 2001). However, no guidelines/formal procedures
to make a final choice are currently available, although many informal
discussions are ongoing. The political atmosphere (including court
litigations) is in flux and dynamic, while new scientific results
are coming available. Compared with the situation on March 2001 when
the current regulation was imposed, economic hardship of the Hawaii
longliners is well recognized, while the effectiveness of the current
regulations for saving sea turtles become more questionable because
the regulation on the HILLF transfer the opportunity of catching swordfish
to non-Hawaii vessels, which would have much higher probability for
interact sea turtles (Kaneko and Bartram "Measuring the environmental
baggage in global marketing of pelagic longline fishery products"
at PFRP PI meeting, Dec. 2003). Furthermore, the current sea turtle
conservation policy (i.e., prohibiting shallow sets) results in a
significant increase in catch of bigeye tuna, while Hampton et al.
(2003) warns that bigeye tuna stock in the Central North Pacific might
be over-fished. The proposed work will provide some methodological
guidelines and recommendations to mitigate such issues.
funding for this 2-year project to be awarded in mid 2004.
Kobayashi, D. and J. Polovina. 2001a. Time/area closure analysis
for turtle take reductions, in NMFS (Ed.). Final Environmental Impact
Statements (FEIS), Vol. 2, Appendix C.
Kobayashi, D. and J. Polovina. 2001b. Evaluation of mitigation measures
for sea turtle take reduction in the Hawaii-based longline fishery.
Oceans 3: 1595.
McCracken, M.L. 2000. Estimation of Sea Turtle Take and Mortality in
the Hawaii Longline Fisheries. Honolulu Laboratory, Southwest Fisheries
Service Center, National Marine Fisheries Service, NOAA, Administrative
Pan, M., P.S. Leung, F. Ji, S.T. Nakamoto, and S.G. Pooley. 2001. A
decision support model for fishery management in Hawaii: a multilevel
and multiobjective programming approach. North American Journal of
Fisheries Management 21:293-309.