11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 10: Ecological Processes on Today's Reef Ecosystems
10.286
The Protective Capacity Of Mangroves During Tropical Storms: A Case Study
From Wilma And Gamma In Belize
Elise GRANEK* 1 , Ben RUTTENBERG 2
1 Environmental Sciences and Management, Portland State University, Portland, OR,
2 Department of Ecology Evolution and Marine Biology, University of California, Santa
Barbara, CA
Globally threatened mangrove forest habitat is often considered an important buffer
protecting coastlines from wave and storm impacts and coastal erosion. However, there is
little empirical data quantifying the protective effects of mangroves during storms,
primarily because of the difficulty of predicting where and when a storm will intersect the
shoreline, to facilitate data collection before and after storm events. In 2005,
opportunistic results from an ongoing study quantifying differences between intact and
cleared mangrove areas on Turneffe Atoll, Belize, provided such pre- and post-storm data
from tropical storms ‘Wilma’ (later a Category 5 Hurricane) and ‘Gamma’. We compared
differences in equipment retention rates of 3 types of experimental devices previously
installed in adjacent intact and cleared mangrove areas. Retention rates were greater in
intact mangrove areas, empirically demonstrating the protective capacity of mangroves
during moderate magnitude storm events. The results support the assumption that
removal of mangroves diminishes coastal protection not only during catastrophic storm
events such as hurricanes or tsunamis, but also during less energetic but more frequent
events, such as tropical storms. This highlights the importance of improved coastal zone
management, as storm events may increase in frequency and intensity with changing
climate, and coastal mangrove forest habitats continue to decline in size and number.
10.287
Lost Of Marine Species At Casa Caiada Beach (Olinda -Pernambuco), Brazil
Mara FISNER* 1 , Carmen MEDEIROS 1
1 Oceanography, UFPE, Recife, Brazil
The beach of Casa Caiada located at Olinda County, (7°58,8’-7°59,7’ S; 34°50,0’-
34°50,3’ W), northeastern Brazil, experiences erosion since 1954. The problem appears
to had resulted from the combined effect of a low sediment supply and a fast and intense
urban occupation. During the 70’s and 80’s, a series of seawalls was constructed along
the Casa Caiada shore on the top of natural beachrocks lines, to propitiated beach
protection. If in one hand the intervention locally reduced the coastal erosion, on the
other hand the reduction on the hydrodynamics propitiated the sedimentation of fine
sediments with prejudice to marine corallines species. In 2003, the presence of the
Scleratinia Siderastrea stellata and Favia gravida, of the zoanthids Zoanthus sp and
Palithoa sp, of the actiniaria Anemonia sargassensis and echinodermata, cirriped and
bivalve were reported at the area by Pereira et al. as well as the fact they was being
stressed by the sedimentation. None of those species could be found in the area during
our visual surveys conducted during four years. Increase in mean water temperature with
values above 25 ºC during winter and reaching 31ºC during summer with averages value
and suspended solids concentration of 36 ppt were verified. The enclosing of the beach
resulted also in decline of water quality. Total and fecal coliforms concentrations were
well above level for primary contact.
Literature citaded:
Pereira, L.C.C.; Jiménez, J.A.; Gomes, P.B.; Medeiros, C. and Rauquírio, A.M.daC.
2003. Effects of the sedimentation on scleractinian and actinian species in artificial reefs
at the Casa Caiada beach (Brazil). Journal of Coastal Research SI35:418-425.
10.288
Assessment Of The Model Hydrozoan, hydractinia Echinata, As A Surrogate For Coral
Early-Life Stage Toxicity Assessments
Marion NIPPER* 1 , R. Scott CARR 2 , Misti GROHMANN 1
1 Center for Coastal Studies, Texas A&M University-Corpus Christi, Corpus Christi, TX,
2 Marine Ecotoxicology Research Station, CERC, US Geological Survey, Corpus Christi, TX
Coral reefs have suffered a variety of insults since the advent of the industrial era and
agricultural monoculture practices, in the form of pollution, excessive nutrient discharges and
climate change. The effect on coral recruitment, survival and sensitivity to disease needs to be
better understood. The infrequent spawning of corals makes it impossible to conduct yearround
early-life stage research with this group. The Cnidarian classes Anthozoa (including
corals) and Hydrozoa share a sessile phase with polyps of a homologous nature. Both classes
have similar embryological development leading to a planula larva, with metamorphosis
induced by specific cues. The similarities of these two Cnidarian classes suggest that colonial
hydroids would be good representatives of corals in a variety of laboratory experiments. The
current study had the objective of analyzing the usefulness of a model hydrozoan, Hydractinia
echinata (Hydrozoa, Hydractiniidae), as a surrogate for corals in assessing the effects of
contaminants on recruitment. The present research focused on the effects of several
contaminants, including polycyclic aromatic hydrocarbons (PAHs), pesticides and heavy
metals, on early development and metamorphosis. The sensitivity of the metamorphosis of H.
echinata to contaminants studied thus far, including copper, sodium dodecyl sulfate and
phenanthrene was equivalent to or higher than that of larvae of several species of coral for
which data were available in the scientific literature. Results to date suggest that H. echinata is
a promising candidate surrogate for assessing the potential effects of contaminants, and possibly
other stressors, on coral recruitment.
10.289
Dispersal Of Coral Larvae With Respect To Egg Buoyancy And Relative Effects Of Wind-
Driven Surface Currents
Masako NAKAMURA* 1 , Kazuhiko SAKAI 1
1 Sesoko Station, Tropical Biosphere Reserch Center, University of the Ryukyus, Motobu, Japan
Spatial and temporal variability in coral recruitment is affected by larval dispersal. Larval
dispersal may be limited by egg buoyancy. Moreover, wind-driven surface currents may
determine recruitment pattern as investigated in other marine sessile invertebrates. We expected
that difference in egg buoyancy would result in different effects of wind-driven surface currents
on larval dispersal. We predicted that larvae from positively buoyant eggs would disperse away
from their natal reefs and their dispersal process would be influenced by wind-driven surface
currents. In contrast, larvae from negatively buoyant eggs would settle on their natal reefs.
Coral recruitment and percent cover of corals were assessed around Iriomote Island (Japan)
using settlement plates and random quadrat method. Acroporid corals were the most abundant
in adult and recruitment communities. Spatial variability in their recruitment had a large annual
fluctuation, and the number of recruits was not correlated with adult percent cover. The annual
fluctuation of acroporid recruitment was likely to be explained by the wind-driven surface
currents. Contrary, although relative abundance in adult and recruitment communities was low,
positive correlation between the adult percent cover and number of recruits was detected in
pocilloporid and poritid corals. Most acroporid and poritid corals release positively buoyant
eggs. The most abundant pocilloporid species in our study areas were Pocillopora verrucosa
and P. eydouxi, and they release negatively buoyant eggs. The results in acroporid and
pocilloporid corals therefore supported our hypotheses, but that in poritid corals did not.
Acroporid corals, which are more susceptible to environmental changes, are more likely to
explore new space by dispersing larvae away from the parent colonies, while the two others,
relatively resistant, tend to disperse larvae locally for filling local empty patches.
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