11th ICRS Abstract book - Nova Southeastern University

22-13
An Appraisal of Marine Resource Use in the Far North of Madagascar: Challenges
and Opportunities for Marine Conservation in Antsiranana
Rachel LENANE* 1
1 Centre for the Environment, The University of Oxford, Epsom, United Kingdom
Design of marine conservation plans can be informed using contextual socio-economic
information to develop conservation strategies that integrate sustainable livelihoods
(Wilkinson et al., 2004; Malleret-King et al., 2006; Richardson et al., 2006).
In Northern Antsiranana, Madagascar, knowledge and beliefs were collected during
interviews with 207 informants over an eight week period. Within this region marine
resources represent a primary source of livelihood for the population and Protected Areas
(PAs) are expanding rapidly under national legislation. By creating a narrative of local
people’s perceptions and use of the marine environment using qualitative methods
possible conservation management strategies are identified.
In Antsiranana the marine resource trade involves numerous stakeholders operating at
various spatial scales; subsistence fishermen to international holothurian exporters.
High levels of artisanal fishing provides subsistence for rural communities. Holothurian
collecting is also an important activity in this region often providing households with
their only source of cash income. Informants identify damaging methods of resource
extraction and declining fish and holothurian populations. Knowledge of government
regulations is limited and the problem is further exacerbated by low levels of formal
education.
Varying types of exploitation need to be identified prior to implementing management
plans as each will have specific environmental and economic impacts. Thus a stratified
management plan is required to protect both livelihoods of coastal inhabitants and marine
ecosystems.
Management strategies explored rely upon a combination of limits on area, time, gear and
size, rather than strict PAs. It is thought that the dispersal of larval fish and holothurians,
and increased pressure on surrounding marine ecosystems by displaced fishers, will have
negligible effects on the benefits of PAs.
Using data from this study, in conjunction with previous ecological surveys, it might be
possible to initiate an integrated, context specific approach to managing these marine
ecosystems of exceptional but declining biodiversity.
22-14
Observations Of Antillean Fish Trap Contents in Southwest Puerto Rico: Ways To
Reduce Coral Reef Habitat Damage And Improve Catch Quality
Anthony MARSHAK* 1 , Ronald HILL 2 , Peter SHERIDAN 3 , Richard APPELDOORN 4
1 Deparment of Marine Sciences, University of Puerto Rico, Mayaguez, Puerto Rico,
2 NOAA Fisheries, Southeast Fisheries Science Center, Galveston Laboratory, Galveston,
TX, 3 NOAA Fisheries, Southeast Fisheries Science Center, Panama City Laboratory,
Panama City, FL, 4 Department of Marine Sciences, University of Puerto Rico,
Mayaguez, Puerto Rico
Abstract: The shelf-wide distribution of Antillean fish traps has been monitored in
southwest Puerto Rico since 2002 to evaluate the benthic impacts of trap fishing within
coralline habitats. Of 1438 traps documented in surface surveys to date, 161, stratified by
habitat, were assessed by divers to quantify damage and record trap contents. Observed
traps were predominantly arrowhead-style traps with 5-cm hexagonal vinyl-coated mesh
composed either of wood or rebar frames. Most traps inspected were found within
colonized hardbottom habitats dominated by soft corals at intermediate depths (12-18 m),
although traps were also surveyed in high relief reef, algal flat, seagrass beds, and
sediment (sand or mud) habitats. Fishes composed 78% of the total individuals caught,
of which butterflyfishes, grunts, surgeonfishes, trunkfishes, and parrotfishes were most
abundant. The Caribbean spiny lobster, Panulirus argus, was the most frequently
trapped species across all habitats. Traps set in colonized hardbottom areas of moderate
to high relief contained the highest numbers of observed organisms. Traps set in high
relief reef habitat caught higher numbers of less valuable herbivorous fishes, with
Chaetodon capistratus and C. striatus being the most numerically dominant species.
Trap contents observed within less structured habitat types, such as algal flats and mud,
consisted mostly of trunkfishes and grunts. Within these habitats, P. argus was the most
frequently observed species. Due to coincident presence of spiny lobster, and a higher
percentage of commercially valuable fish species, the results suggest that fishers could
improve economic efficiency by fishing traps only in areas of lower structural
complexity, while lessening potential for gear damage to more complex coralline habitat
types.
Oral Mini-Symposium 22: Coral Reef Associated Fisheries
22-15
Parrotfish Densities Across A Fishing Intensity Gradient in The Caribbean
Denise DEBROT* 1 , J. Howard CHOAT 2 , Juan M. POSADA 3 , D. Ross ROBERTSON 4
1 Dpto. Biología de Organismos, Universidad Simón Bolívar, Caracas, Venezuela, 2 James Cook
University, Townsville, Australia, 3 Dpto, Biología de Organismos, Universidad Simón Bolívar,
Caracas, Venezuela, 4 Smithsonian Tropical Research Institute, Panamá, Panama
Parrotfishes (Scaridae) are important components of subsistence and commercial reef fisheries
throughout the Caribbean, most notably at locations were predators (e.g. groupers, snapper)
have been intensively fished. Here, we compare the abundance of scarids at seven localities
across a latitudinal gradient in the Caribbean (from west to east, Belize, San Blas, Curacao,
Bonaire, Las Aves, Los Roques and Barbados) with differing fishing intensities for parrotfishes.
At each locality we surveyed at least five sites separated by kilometers, and across different reef
habitats. To estimate densities, counts were made for all species of scarids along 30 x 10 m belt
transects, and along 400 x 15 m transects for the large bodied scarids. Los Roques, a National
Park offshore Venezuela were fishing is restricted, supports the highest densities of the largebodied
scarids Scarus guacamaia, S. coelestinus and S. coreuleus. At the neighboring Las Aves,
an area heavily fished for predators, but with little fishing directed to scarids, densities were
also high for S. coelestinus and S. coreuleus. Bonaire, a well protected reserve, supported the
highest densities of the excavating scarid Sparisoma viride and the large grazing scarid Scarus
vetula. In contrast, the densities of the large bodied parrotfishes at moderate to intensively
fished sites (San Blas, Belize, Barbados and Curacao) were up to 10-fold lower than at Los
Roques, and were absent from all sites at Barbados. Our results suggest that parrotfish may be
vulnerable to intensive fishing, and thus highlight the importance of fisheries management for
the protection of reef fishes.
22-16
The Effects Of Fishing And Harmful Algal Blooms On Sponge Ecology in The Florida
Keys Usa
Donald BEHRINGER* 1 , Mark BUTLER IV 2
1 Department of Fisheries and Aquatic Sciences, University of Florida, Gainesville, FL,
2 Department of Biological Sciences, Old Dominion University, Norfolk, VA
Sponges are a prominent component of coral reefs and, along with octocorals, they dominate
the biota of shallow hard-bottom habitat in the Florida Keys (Florida, USA) marine ecosystem.
Yet, remarkably little is known about the ecology of the large sponge species that dwell in hardbottom
or the structure, ecological function, or resilience of hard-bottom communities. Our
poor understanding of these communities has been highlighted in recent years by questions
about the possible impacts of ecosystem perturbations and resource exploitation on hard-bottom
habitat. For example, hard-bottom communities in Florida have been subject to recurring algae
blooms which can cause massive sponge die-offs; the most recent occurring in 2007.
Furthermore, there are concerns about the possible ecological impacts of commercial sponge
fishing on hard-bottom community structure and function. In the case of sponges, resolution of
these issues has been hampered because there is no stock assessment, the most basic population
dynamics for the pertinent sponge species are largely unknown, and the effect of the fishery on
commercial sponges and allied species have never been studied. We conducted a series of
studies to better understand: (a) the basic population dynamics of commercial sponges, (b) the
impact of the sponge fishery on sponge communities, and (c) the effect of a cyanobacteria
bloom in 2007 on sponge and octocorals abundance and diversity. This presentation will
highlight the key findings of each of these studies, which suggest that sponge communities are
robust to current rates of commercial sponge exploitation but are rapidly decimated by the
cyanobacteria blooms that continue to plague Florida Bay.
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