11th ICRS Abstract book - Nova Southeastern University

22-17
Managing Fishing Gear To Encourage Ecosystem-Based Management Of Coral
Reefs Fisheries
Tim MCCLANAHAN* 1 , Josh CINNER 2 , Joseph MAINA 3 , Carlos RUIZ
SEBASTIAN 4 , Shaun WILSON 5 , Nick GRAHAM 5
1 Marine Programs, Wildlife Conservation Society, Mombasa, Kenya, 2 Marine Biology,
James Cook University, Townsville, Australia, 3 CRCP, Mombasa, Kenya, 4 CRCP,
Durban, Australia, 5 Marine Science, University of Newcastle, Newcastle, United
Kingdom
We present data from two poor tropical countries, Papua New Guinea and Kenya, and
show that there is a unique and consistent partitioning of the capture of species and
functional groups by gear that can be used to potentially influence ecological processes
and biodiversity on coral reefs that can also respond to disturbances such as coral
bleaching. Hook and line capture a higher proportion of top carnivores/piscivores and
target species with low susceptibility to coral bleaching. Traps and spear guns capture
mostly herbivores/ominvores and target the highest proportion and number of fish species
that are moderately susceptible to the impacts of coral bleaching. Nets mainly target
carnivores/invertivores. The use of specific gear can be actively managed to encourage
the recovery of select functional groups and adaptively managed under conditions such as
high erect algae cover, sea urchin dominance, low coral cover, and coral bleaching. We
present a simulation and conceptual model that examines projected effects of the gear and
effort on the yields and ecological processes in the coral reef ecosystem and suggest
mechanism for how this model might be practically implemented.
22-18
Evaluation Of Alternative Management Strategies For The Eastern Torres Strait
Reef Line Fishery
Ashley WILLIAMS* 1 , Rich LITTLE 2 , Gavin BEGG 3
1 Fishing and Fisheries Research Centre, School of Earth & Environmental Sciences,
James Cook University, Townsville, Australia, 2 Marine and Atmospheric Research,
CSIRO, Hobart, Australia, 3 Australian Fisheries Management Authority, Canberra,
Australia
Commercial harvest of coral reef fish in the eastern Torres Strait (ETS), Australia is
shared between Torres Strait Islanders and non-indigenous fishers, but to date no formal
assessment of the fishery has been done, and no resource allocation or management
strategies directed at the special circumstances in the Torres Strait currently exist. Here,
we evaluate the strengths and weaknesses of a range of alternative management strategies
related to the harvest and conservation of coral trout (Plectropomus leopardus), the
primary target species in the ETS Reef Line Fishery (RLF). We worked with Islander and
non-indigenous commercial fishers and fisheries managers to identify specific
stakeholder objectives and feasible alternative management strategies to pursue them. We
used a meta-population and harvest simulation model (ELFSim) to assess the combined
effects of four regimes of effort control, three minimum legal size regimes and two area
and two seasonal closure regimes on the status of coral trout, and compared their
likelihoods of meeting conservation and fishery objectives. Results of simulations
indicated that a two-month seasonal closure was a good measure for addressing
conservation objectives, but tended to reduce the ability to satisfy fishery objectives.
Similarly, closing areas to fishing and increasing the minimum legal size were generally
good strategies for conservation objectives, but performed poorly for fishery objectives.
Lowering effort was the more robust strategy for achieving both conservation and fishery
objectives. This research provides a framework for the impartial evaluation of the
performance of alternative management options to meet diverse and often competing
objectives of stakeholders in the ETS RLF.
Oral Mini-Symposium 22: Coral Reef Associated Fisheries
22-19
The Status Of The Artisanal Seine Net Fishery in Rodrigues Over A 5-Year Period
Emily HARDMAN* 1 , Alasdair EDWARDS 2 , Jovani RAFFIN 1
1 Shoals Rodrigues, Rodrigues, Mauritius, 2 Division of Biology, University of Newcastle upon
Tyne, Newcastle upon Tyne, United Kingdom
The seine net fishery is of great socio-economic importance to Rodrigues, with landings making
a significant contribution to the total catch (42% of lagoon fish catches). Fishing activities
however, appear to be impacting on fish stocks and catches have declined significantly between
1994 and 1997. An assessment of the status of the fishery commenced in 2002 and 5 years of
data have now been obtained. Working in collaboration with 4 fishing teams during the seine
net open season, the total length of each individual caught was determined. Over the 5-year
period a total of 68,013 fish were measured. The data show that the Catch per Unit Effort and
mean monthly earnings per fisher have declined significantly during this 5 year period.
Although the fishery is highly multi-species with 122 species recorded, 80% of the fish landed
were from 10 species, most of which are herbivores or small invertebrate feeders. The most
important species during all years was the Rabbitfish, Siganus sutor. There has however been a
change in species composition of the catch over the 5 year period with species such as Naso
unicornis decreasing in abundance, whereas small species such as Acanthurus triostegus and
Gerres longirostris increased in importance. The modal length of S. sutor, Lethrinus nebulosus
and Caranx melampygus has decreased between 2002 and 2006 and over 60% of fish were
caught before they reached maturity. The data indicate that the fishery has become dominated
by small, herbivorous fish and that serious recruitment overfishing is occurring for some
species. As a result, 4 marine reserves have now been proclaimed in Rodrigues in order to allow
fish stocks to recover and to promote sustainability of fisheries in the Rodrigues lagoon.
22-20
Coral Reef Fisheries For The Future? Know The Historic Baseline
Dirk ZELLER* 1 , Shawn BOOTH 1 , Roxanne DICKINSON 2 , Lou FROTTÉ 3
1 Fisheries Centre, University of British Columbia, Vancouver, BC, Canada, 2 Stanford
University, Stanford, CA, 3 Insitut National Polytechnique de Toulouse, Castanet, France
Small-scale fisheries in the tropical Pacific are important culturally and for food security, yet
remain extensively under-reported in national statistics which inform global data presented by
the Food and Agriculture Organization of the United Nations (FAO). This contributes
substantially to the undervaluation of their importance to communities, both socio-politically as
well as economically. We present historic baseline catch reconstructions for the 1950-2004
period for 20 small island countries in the tropical Pacific. The reconstruction approach
develops estimates of likely total catch using all available information sources, including grey
literature and localised case-studies, combined with conservative assumptions, expansions and
interpolations. The reconstruction suggests that unreported catches over this time period were at
least equal to reported catches, but range as high as a 17-fold discrepancy. Important also is that
for several countries the time series reverses from an increasing to a declining trend over time.
This is likely due to localised overfishing, as well as changing consumption patterns in an era of
generally high population growth rates and increasing population centralization. The
discrepancy in national and hence FAO statistics is primarily driven by consistent underrepresentation
of non-commercial (subsistence) catches in most of the island countries. While
reliable yearly estimates are expensive and difficult to obtain, and are the prime reason for
incomplete catch accounting by many counties, the fundamental importance of these catches to
food security, especially under increasing climate change stresses cannot be underestimated.
Regular, albeit non-annual, country-wide estimates of total catches should be undertaken as a
priority activity by all countries, interpolated for intervening years, and included in national data
reported to FAO. Due to financial and human resource limitations, such work should be
facilitated or undertaken by regional agencies, e.g., the Secretariat of the Pacific Community
(SPC).
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