Title: Monitoring Impacts of Climate Change on Oceanic Fisheries (Filling Important Information Gaps) John Hampton Oceanic Fisheries Programme, SPC
1Monitoring Impacts of Climate Change on Oceanic
Fisheries(Filling Important Information
Gaps)John HamptonOceanic Fisheries Programme,
SPC
2Monitoring Climate Change in Oceanic Fisheries
- Impacts on target species (tunas)
- E.g., recruitment, natural mortality, growth,
movement, reproduction - Impacts on the underlying ecosystem
- Pelagic food web, trophic structure, biodiversity
- Impacts on the fisheries
- Distribution and performance (CPUE), size
composition, species composition - Subject of ongoing programmes of data collection
and stock assessment
31. Impacts on Tuna
- SEAPODYM model is a model of high spatial
resolution, that may be suitable as a monitoring
and forecasting tool - Can assimilate environmental, biological and
fisheries data in near-real time
High-resolution modelling of skipjack population,
with catches (circles) overlain
- With a good understanding of the way that ocean
environment interacts with tuna biology, we can
predict responses of tuna stocks and fisheries
through simulations forced by climate change
model scenarios
4Early Results of Simulations
Skipjack
Bigeye
5SEAPODYM-Based CC Modelling
- Phase 1 (1 year, in progress, funded by Aus
DCCEE) - Revise skipjack and bigeye simulations using new
forcing data - Extend to yellowfin and South Pacific albacore
- Run simulations for A2 and B1 scenarios
- Phase 2 (3 years, funding being sought)
- Further develop simulations, e.g. to include
effects of ocean acidity - Apply a plausible ensemble of IPCC-class
simulations to bound uncertainty in tuna
responses - Sub-regional/national applications using
down-sized data
6Future Climate Change Impacts
- Use the SEAPODYM framework to monitor in
near-real-time, and to predict into the future - The reliability of model estimates dependent on
- Accurate high-resolution output of models of
physical/biological oceanography conditioned
on/validated by extensive observations - Accurate high-resolution fisheries data
(collected as part of the regular OFP fishery
monitoring work programme) - Fishery-independent data that are directly
informative on the processes liable to be subject
to change movements, natural mortality, growth
7Tuna Tagging
- Tuna tagging can provide direct data on tuna
biological process for use in CC monitoring and
prediction
Bigeye Tuna
Skipjack Tuna
8CC Monitoring Proposal 1
- Regular (annual) structured tagging surveys to
monitor dynamic processes (movement, growth, etc)
likely to be impacted by CC - Surveys would provide empirical indicators of
change - Data assimilated into SEAPODYM models would
enhance predictive capabilities - Currently have funding (USD 3 million) for 3 x 3
month annual tag release cruises in PNG - Additional funding to extend that work into other
areas of the Western and Central Pacific
92. Changes in the Underlying Ecosystem
- Climate change impacts on target tuna species are
fairly readily observable - However, changes at lower trophic levels may also
occur, and if observable, could provide an early
warning system for pending large-scale changes
in the tropical pelagic ecosystem - Observing lower trophic levels (baitfish, squid,
small crustaceans, etc) directly is logistically
difficult and costly
10Tuna Stomach Contents Sampling as an
Observational Window
11Sampling of Top Predator Stomachs
12CC Monitoring Proposal 2
- Establish baseline data set from existing data
- Design structured sampling programme utilizing
national regional longline observer programmes - Conduct ongoing sampling and analysis of tuna and
other top predator stomachs as a means of
observing changes in mid-trophic levels - Incorporate these data along with catch estimates
for target species and bycatch into ecosystem
models - Potential to also consider new acoustic
monitoring data from buoys and ships of
opportunity