11th ICRS Abstract book - Nova Southeastern University

22.867
Fish Spawning Aggregations At Gladden Spit, Belize-A Slippery Subject
jocelyn FINCH* 1 , Julianne STOCKBRIDGE* 2 , Shayne PECH 3 , Lindsay GARBUTT 3
1 Toledo Association for Sustainable Tourism and Empowerment, Punta Gorda, Belize,
2 The Nature Conservancy, Belmopan, Belize, 3 Friends of Nature, Placencia, Belize
Gladden Spit Silk Cayes Marine Reserve (GSSCMR) protects an important spawning
aggregation site for over 24 species of reef fish, including a variety of snapper, grouper,
jacks and other reef fish. In addition the spawning aggregation site is an attraction for
whale sharks (Rhincodon typus) that predictably aggregate to feed on the fish spawn.
The spawning site at Gladden is of critical ecological, economic and social value and
demands innovative management. In 2002 a local Non-Government Organization
(NGO), Friends of Nature (FoN), signed a co-management agreement with the Belize
Fisheries Department for the management of GSSCMR. Over the past five years Friends
of Nature has worked closely with local stakeholders, NGO’s, the Government of Belize,
the Nature Conservancy, and other partners to improve management of this important
multiple species fish spawning site. A key component to the on-going management has
been the monthly monitoring of spawning aggregation using the Reef Fish Spawning
Aggregation Monitoring Protocol for the Mesoamerican Reef and the Wider Caribbean.
After five years of active management, including monitoring, enforcement and education,
FoN has collected a significant amount of information about the status of the site and
particularly the status of the aggregating species. In order for FoN to effectively manage
GSSCMR and maintain a sustainable fishery, it becomes critical for managers and
researchers to evaluate what, if any, impact is actually being felt at the site. Through
careful evaluation of the data collected and discussions with resource users it should be
possible for managers to determine the impact of GSSCMR on the fisheries resources and
to evaluate the next steps in order to ensure effective and adaptive management of these
important resources.
22.868
Evolution Of Small Scale Fisheries Net Gears Selectivity To Preserve Marine
Turtles in Martinique And Guadeloupe, Fwi
Laurent LOUIS-JEAN* 1 , Philippe LENFANT 2 , René GALZIN 2 , Eric DELCROIX 3 ,
Jean-Philippe MARÉCHAL 4
1 OMMM, Fort-de-France, Martinique, 2 EPHE - University of Perpignan, Perpignan,
France, 3 Réseau tortues marines de Guadeloupe, Trois-Rivières, France, 4 OMMM, Fortde-France,
France
The conservation plan for marine turtles in the FWI has been approved by the National
Council for Nature Conservation in 2006. A major objective was to identify the main
threats on marine turtles. Local fishing gears kill hundreds of turtles every year through
by-catch. Bottom trammel nets and gillnets targeting fishes, queen conch and spiny
lobsters are first concerned. Their number and use have increased in the past few years. It
is believed that their impact on marine resources is not compatible with long term
management. In this study, experimental fishing was conducted to compare species
selectivity between new designed nets and the current gears used in the FWI. The
productivity of both gill nets and trammel nets was compared. Parameters such as height
and mesh size were studied. Changes in catches were also compared to determine the
weight of each parameter. Three specific study areas were chosen according to targeted
species and marine turtles presence. Our objective is to develop gears and techniques that
would preserve marine resources and significantly reduce marine turtles by-catch in the
long term. Finally we should select the most selective - modified or new - fishing gears
with no or significant reduced impact on marine turtle population in the FWI.
Poster Mini-Symposium 22: Coral Reef Associated Fisheries
22.869
Influence Of Habitat Structure And Population Density On The Distribution And
Survival Of Four Species Of Harvested Coral Reef Fishes
Clare WORMALD* 1 , Mark STEELE 2
1 University of Rhode Island, Kingston, RI, 2 California State University Northridge, Northridge,
CA
Effective conservation and management strategies are needed to sustain harvested coral reef
fish populations that are impacted by habitat loss and overexploitation, however, little is known
about how the demographic rates of harvested reef fish respond to changes in habitat quality or
to fluctuations in population density. This study examined four species of ecologically similar,
harvested coral reef fishes to evaluate habitat associations and assessed the influences of habitat
and population density on survival.
The degree of habitat association differed among the four study species. Densities of
schoolmaster snapper (Lutjanus apodus) and French grunt (Haemulon flavolineatum) were
strongly tied to habitat structural components (coral and limestone boulders), whereas white
grunt (H. plumierii) density was not predictable based on this aspect of the habitat, and lane
snapper (L. synagris) density was negatively associated with this habitat attribute.
Despite the varied relationships between density and habitat features, correlative tests did not
reveal any influence of habitat on survival of the four species. Nor did correlative tests reveal
any effects of density on survival. A large-scale density manipulation experiment with the
schoolmaster snapper, however, revealed that survival was positively affected by density. The
positive effect of density on survival of the schoolmaster snapper contrasts with the results of
most studies on small, non-exploited coral reef fishes. The inverse density dependence detected
in the schoolmaster snapper implies that regulatory mechanisms that would help populations
recover from overfishing may be absent in this species, but that marine protected areas may be
particularly effective for management and conservation of this and similar species.
22.870
Body Size And Abundance Relationships in Tropical Eastern Pacific Reef Fishes: Testing
The Energetic Equivalence Rule
Carlos MUÑOZ* 1 , Fernando A. ZAPATA 1
1 Department of Biology, Universidad del Valle, Cali, Colombia
The Energetic Equivalence Rule (EER) proposes that the energy required by a species
population is independent of its body size. The EER is evident when the body size–abundance
and metabolic requirements-body size relationships are linked and the slopes (allometric
coefficients) from these relationships have the same magnitude and opposite sign. To test the
generality of the EER we examined the relationship between body size and abundance in reef
fishes from the Tropical Eastern Pacific (TEP). We used abundance data gathered from
published studies done in different localities from the TEP (Gulf of California, Costa Rica,
Colombia and Galapagos islands) covering much of the TEP region. Body size data were
obtained from several papers and digital data bases. Abundance was generally negatively
correlated with body size with allometric coefficients ranging between -0.06 and -0.42.
Although abundance scaled as a negative power of body size according to the EER, the
magnitude of the allometric coefficients between abundance–body size and metabolic
requirements–body size relationships differed significantly (p < 0.0002 in all cases). Thus, the
EER is not supported by our analysis in TEP reef fishes. Among reef fishes bigger species
appear to have a greater energetic impact on the environment than the smaller ones.
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