11th ICRS Abstract book - Nova Southeastern University

Poster Mini-Symposium 4: Coral Reef Organisms as Recorders of Local and Global Environmental Change
4.67
Using Nearshore Macrobenthos As Environmental Indicators Adjacent To A Major
Navigational Inlet: Port Everglades Inlet, Florida
Jessica CRAFT* 1
1 Marine Science & Biological Research, Coastal Planning & Engineering, Boca Raton,
FL
The reefs off Broward County, Florida, lie near the northernmost limits of tropical coral
reefs, are non-accreting, and have long been affected by human influences including
land-based sources of pollution. Port Everglades may be a source of many anthropogenic
contaminants, including freshwater and nutrients, which are discharged in a plume that
sweeps over the coastal reef. The results of two nearshore reef studies were used here
to determine if the inlet effluent plume produces a water quality gradient and associated
biological gradient, and if any biological indicators of water quality can be determined.
Water quality variables, including nutrients, specific conductivity and chlorophyll levels,
were analyzed. Results indicate a low-salinity wedge being discharged from the inlet
at low tide, which is significantly correlated with increased levels of chlorophyll.
Nutrients, including nitrates and nitrites, phosphorus, and TKN, also show peak levels
occurring around the mouth of the inlet.
Macrobenthos cover at 33 sites from two separate studies was also assessed from Port
Everglades inlet south to the Broward County line. Although preliminary results of the
first study indicate that coral cover in the nearshore appears to be dependent on substrate
variability, macroalgae cover was shown to significantly increase with proximity to Port
Everglades inlet. No significant trends were determined from sponge abundance. These
results suggest that Port Everglades may be a source of coastal pollution and freshwater
discharge, causing localized increases in algal abundance which may be detrimental to
the benthic ecology of the surrounding nearshore reef.
4.68
Evidences Of Magdalena River As A Sporadic Stress Factor To Coral Reefs in
Tayrona National Park (Colombia)
Iliana CHOLLETT-ORDAZ* 1,2 , Alberto RODRÍGUEZ-RAMÍREZ 3 , Eduardo KLEIN 2
1 Marine Spatial Ecology Lab. University of Exeter, Exeter, United Kingdom, 2 Instituto de
Tecnología y Ciencias Marinas. Universidad Simón Bolívar, Caracas, Venezuela,
3 Instituto de Investigaciones Marinas y Costeras, Santa Marta, Colombia
In disturbance ecology, scale matters. "Coral reefs are affected by disturbances operating
at different scales in space and time", is a standard sentence that can be found in almost
every coral reef ecology book. However, sometimes transient events act at overlooked
and surprising scales.
Coral reef degradation in Tayrona National Park, Colombia, has been related to the
influence of continental waters from local - Ciénaga Grande de Santa Marta, a coastal
estuarine lagoon, Gaira and Manzanares Rivers- and regional sources -Magdalena river-
and the gradual increases of siltation, turbidity and nutrient loads. A neural networks
analysis of 10 years of SeaWiFS satellite derived chlorophyll maps, revealed that the
eastern Colombia Caribbean Sea experiences a very predictable annual pattern in ocean
colour, only interrupted in 8 scenes (0.003% of the total) during two transient events in
1999 and 2000. In these two brief periods, Magdalena River's plume experienced a
change in its westerly direction, tipping to the north and then to the east, reaching
Tayrona. During the events, estimated surface chlorophyll concentration raised 16.07
mg/m 3 above the 10 year climatological mean (0.99±1.88 mg/m 3 ). These mesoscale
perturbations, in synergy with a bleaching event in 1998 and the impact of hurricane
Lenny in 1999, concurred with the largest annual reduction of coral cover in Bahia de
Chengue, Tayrona: -3.6 and -5.1% during 1998/1999 and 1999/2000, related to an
average absolute annual change of 1.7 1.2% in 12 years of monitoring.
The evidenced occasional but strong impact of the Magdalena River over Tayrona
National Park might act as a stress factor for its coral reefs. Such mesoscale sporadic
events may trigger large changes in coral cover, and must be included to the big picture
assessments of Tayrona ecosystems.
4.69
Application Of The Sedcon Index On Patch Reefs in Biscayne National Park, Florida
Alexa RAMIREZ* 1 , Camille DANIELS 1 , Pamela HALLOCK 1
1 College of Marine Science, University of South Florida, St Petersburg, FL
A simple index has been developed to assess the integrity of a reef system using sediment
composition. The Sediment Constituent (SEDCON) Index is based upon the long-established
methods of sedimentological facies interpretation using grain constituents, along with
observations that phase shift in benthic communities is reflected in sediment composition.
Shells of symbiont-bearing foraminifers, along with physically eroded, identifiable
zooxanthellate coral fragments, characterize reef sediments in oligotrophic waters conducive to
reef accretion. In contrast, higher proportions of shells of smaller, heterotrophic foraminifera,
unidentifiable carbonate grains, and calcareous algae fragments tend to increase with increasing
nutrient flux or other changes in water quality.
Biscayne National Park (BNP), Florida, contains over 4000 reefs in a relatively small area in
relatively close proximity to a major urban area. Thus, BNP is an ideal location to test the
SEDCON Index. Sediment samples were hand-collected by divers at 32 patch reefs in BNP in
May 2007. Several environmental parameters also were measured at each site sampled. The
sediment samples were individually assessed microscopically by identifying and counting the
constituents in a 300-grain subsample. SEDCON Index values were calculated from the
resulting data.
Interpolation maps were created for the SEDCON Index values for the sampled patch reefs, as
well as for temperature, salinity, pH, and dissolved oxygen data. Spatial correlations were
carried out between interpolation maps. Significant correlations were found between the
SEDCON Index values and temperature and salinity, which implicate the influence of Biscayne
Bay water on the patch reefs. Identifying the aspects of bay water responsible for the observed
spatial patterns could be an important step in mitigating the loss of coral cover in BNP and
elsewhere along the Florida reef tract.
4.70
A Comparison Of Chemical Records in Montastraea Faveolata And Siderastrea Siderea
As Examined By Laser Ablation Icp-Ms: A Look At Methodology For Caribbean Coral
For Seasonal And Storm Events
Alan KOENIG* 1 , Jessica CARILLI 2 , Noreen BUSTER 3
1 Mineral Resources Team Denver, US Geological Survey, Denver, CO, 2 Scripps Institution of
Oceanography, La Jolla, CA, 3 FISC Coastal and Watershed Science Team, US Geological
Survey, St. Petersburg, FL
The importance of understanding past and recent climate and environmental patterns is no more
evident than now. The utility of corals to decipher paleoclimate records such as temperature,
salinity and ocean chemical patterns has been demonstrated. Most trace-element studies of coral
have utilized bulk-sampling techniques such as microdrilling or Laser Ablation-Inductively
Coupled Plasma-Mass Spectrometry (LA-ICP-MS) for small framework coral such as Porites.
The large framework of M. faveolata leads to sampling problems with LA-ICP-MS. Detailed
LA-ICP-MS analyses and SEM imaging of ablation tracks in M. faveolata indicate that
inadvertent sampling of multiple or discontinuous skeletal elements can lead to false
interpretations (Buster and Koenig, in prep.). Cores of M. faveolata and S. siderea were
collected within a 20-meter radius at Frank’s Caye in southern Belize. A comparison of LA-
ICP-MS of identical time periods in these cores indicate that the smaller framework of S.
siderea provides a clearer seasonal signal in metals without the noise introduced by sampling
problems as in M. faveolata. We will compare data from different resolutions within M.
faveolata utilizing bulk methods at monthly and yearly intervals and LA-ICP-MS at various
spatial resolutions. Bulk annual samples in M. faveolata show spikes that correlate with known
hurricane events, although not all events are resolved. Monthly drilled samples resolve
seasonal cycles in Ba/Ca, with increasing variance toward the present indicating increasing
runoff associated with land use change, however known hurricane events are still not all
resolved. LA-ICP-MS provides higher resolution measurements of metals, and may help
determine whether known events have not previously been resolved due to smoothing by lowresolution
sampling, or if the signal is not being recorded.
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