11th ICRS Abstract book - Nova Southeastern University

22.883
Differential Depth Effects Upon Biomass Patterns in An Herbivorous Coral Reef
Fish Assemblage
Michael NEMETH* 1 , Richard APPELDOORN 1
1 Department of Marine Sciences, University of Puerto Rico, Lajas, Puerto Rico
Herbivory is an ecological process that structures coral reef benthic communities and
variations in the spatial distribution of herbivores may reflect differential grazing
pressure. This study investigates spatial patterns of parrotfish and surgeonfish biomass on
fore-reef habitats across the seascape. Abundance was sampled on 6 reefs along an
inshore-offshore gradient in La Parguera, Puerto Rico to allow within reef (across depths)
and among reef (cross-shelf) comparisons. Temporally replicated visual surveys were
conducted along permanent belt transects (100m2) at three depth intervals (5, 10, 15 m)
to obtain data on fish species density and lengths used to calculate biomass. La Parguera
supports an active fishery and large species of parrotfish were rare or absent. The
herbivorous fish assemblage was dominated by small-bodied parrotfishes Scarus iseri,
Sparisoma aurofrenatum S. viride and the blue tang, Acanthurus coerulus. Overall,
parrotfish biomass was 2.3 times higher at 5 m depth than at15 m; for surgeonfish it was
4 times higher. These depth-related differences were most notable at inshore reefs where
biomass at 5 m was 3.2 and 10.9 times greater than at 15 m for parrotfish and
surgeonfish, respectively; on offshore reefs the respective proportional differences were
1.8 and 2.8 times. Individual species followed this general pattern. In addition, higher
biomasses were found at those reefs and depths within reefs characterized by higher relief
and a greater % cover of live coral and coralline algae. Depth is a well known driver of
herbivorous fish abundance, but along a cross-shelf gradient additional within reef factors
interact to structure biomass patterns. That use of fore-reefs by the dominant species of
herbivores is site specific but somewhat predictable has implications for management
strategies that aim to promote fish grazing.
22.884
Seasonality And Long-Term Changes in Reef Fish Population At Caye Caulker
Marine Reserve, Belize, C.a.: 1: Preliminary Overview
Ellen MCRAE* 1,2
1 The Siwa-ban Foundation, Caye Caulker, Belize, 2 Forest and Marine Reserves
Association of Caye Caulker, Caye Caulker, Belize
Caye Caulker Marine Reserve (CCMR), Northern Shelf Lagoon, Belize, is centered along
an 11-km stretch of the Belize Barrier Reef off the mangrove-sand island of Caye
Caulker. Important time benchmarks to reef fish populations include Reserve enactment
(Apr 1998); major near-miss hurricanes Mitch (Oct 1998) and Iris (Oct 2001), and direct
hit Hurricane Keith (Sep-Oct 2000). Formal on-site management commenced 2003;
however conservation zones, though proposed within the IMP (2004) and updated in
2006, have not as yet been formally gazetted by Government, resulting in some confusion
about site use during the past four years.
Reef fish populations were noted in 30-minute timed rover diver mask and snorkel
surveys in selected backreef and channel locations along reef ribbons at CCMR, , Belize,
commencing 2005. Though most reef fish surveys concentrate on specific groups, this
dataset was constructed around total biodiversity. In this overview patterns of reef fish
occurrence at backreef and channel locations are analysed relative to conservation status
of the areas. The most commonly observed species (sighted every site visit) fell into five
families-Lutjanidae, Haemulidae, Pomacentridae, Labridae, and Scaridae.
For time series comparison a less formal dataset collected in the same areas ancillary to
tourism from 1991-2007 was reviewed as to relative abundance, also alongside
conservation status data. One major difference noted between the early data prior to
CCMR enactment is the near absence of Lutjanids; this is undoubtedly a function of the
unrestricted spearfishing that took place at the South Caye Caulker Channel and adjacent
backreef areas.
Poster Mini-Symposium 22: Coral Reef Associated Fisheries
22.885
Movement Patterns Of Queen Conch, strombus Gigas, And Utilization Of Coral Reef-
Associated Habitats in St. John, U.s. Virgin Islands
Jennifer DOERR* 1 , Ron HILL 1
1 NOAA Fisheries Service, Galveston, TX
Habitat utilization and movement patterns of queen conch, Strombus gigas, differ by size and
maturity status, making it important to identify areas and habitat types that may influence the
recovery of this species. Estimates of home range size, distribution dynamics, and movement
patterns in benthic habitats associated with coral reef areas are central to developing spatial
management policies for fisheries and can prove invaluable in identifying essential fish habitats.
Vemco VR2 autonomous hydrophone receivers and coded acoustic tags are currently being
used to track long-term movements and spatial distributions of queen conch in two bays in St.
John, USVI, Fish Bay and No Name Bay. Hydrophone arrays were placed in each bay to match
detection zone boundaries with changes in benthic habitat types to allow discrimination of
habitat use. Receiver placements near the mouths of the bays permit detection of conch moving
from shallow to deeper waters, an expected seasonal movement associated with spawning.
During each of three field visits per year, uniquely coded acoustic tags are cemented onto the
shells of number-tagged queen conch of varying size and maturity. To date, a total of 41
acoustic tags have been deployed in Fish Bay and 26 in No Name Bay. Preliminary analysis of
acoustic telemetry data shows limited movement of small conch with little variation in habitat
use. As conch increase in shell size and maturity status, movement rates intensify and
utilization of habitats becomes more variable in response to seasonal shifts in water temperature
and the subsequent onset of spawning activity. Continued collection of acoustic data will
provide information necessary to further understand habitat utilization and movement patterns
of queen conch in the U.S. Virgin Islands.
22.886
Composition Of One Of The Southern Reef Fish Community in Brazilian Coast.
Jonas LEITE* 1 , Mauricio HOSTIM-SILVA 2
1 Programa de Pós Graduação em Zoologia, Universidade Federal do Paraná - UFPR, Rio de
Janeiro, Brazil, 2 Centro de Ciências Tecnológicas, da Terra e do Mar, Universidade do Vale do
Itajaí - UNIVALI, Itajaí, Brazil
The tropical Atlantic reef fauna encompasses four primary provinces: Brazil, Caribbean, the
Mid-Atlantic Ridge, and the Eastern Atlantic. The freshwater outflow from the Orinoco and
Amazon rivers, which spans 2300 km of the NE coast of South America, separating Brazilian
and Caribbean reef habitats. The Brazilian coast is separated in tree different regions:
Northeastern from the mouth of the Amazon river to southern Bahia, Southeastern from Espirito
Santo to Santa Catarina, and four oceanic islands, Atol das Rocas, Fernando de Noronha, St.
Paul’s Rocks and Trindade. Santa Catarina state is the limit of distribution for the most of the
Atlantic reef fishes. This research was carried out in Campeche Island (27º41’22’’ S /
48º28’18’’ W), in Santa Catarina state. There was used the method of visual sub-aquatic census
with belt transect (20X2 meters). This non-destructive method was used for determination of
richness and relative abundance without disturb the local fauna. The study area is characterized
by rocky shores since the reefs formations do not occurs in this latitude. At the study area
Serranidae (6 sp.), Haemulidae (5 sp.) and Pomacentridae (4 sp.) presented the higher relative
richness. Two species presented the higher abundance, Parablennius pilicornis and
Parablennius marmoreus . Three species are in the IUCN Groupers & Wrasses Specialist
Group List: Epinephelus marginatus, Epinephelus niveatus and Mycteroperca bonaci. This
species presented a great number of young individuals (