Current Research
My current research focuses on corals at several ecological levels.
Though much of my physiological experiments is at the organismic level,
I use ecological techniques to assess the population, and community
structure of these reefs. First, I monitor the reef system itself
using several monitoring techniques. This effectively give me an
understanding of the dynamics of the reef. I then assess abiotic and
biotic factors affecting the reefs in their natural environment.
Finally, I use all this information to design physiological experiments
that can effectively provide answers about how the reef is responding
to changes in our environment. A very important step is to establish
links between the physiological performance of individual organisms and
the community dynamics of the reef.
Subtidal and sea surface temperature
(SST) comparisons in reef systems
This study assesses the effectiveness of satellite data in providing
information on the subtidal thermal environment at two distinct
reef locations in the western Caribbean. Sea surface temperature
derived from MODIS Aqua and Terra platforms were compared with in situ
seawater temperature collected at 3-5 m from the inner and outer reefs
of southern Belize from June 2002 to December 2007. Results suggest a
negative
(cool) bias between remotely sensed and in situ measurements at
these two locations.
Hobo
Loggers next to Seabird MicroCAT
Coral photophysiological response
The purpose of this study was twofold, first, it was to assess and
compare ambient seawater temperature and maximum photochemical
efficiency of
electron transport through photosystem II (Fv/Fm)
of Symbiodinium in Montastraea faveolata in situ
across various depths in the inner lagoon reef and outer barrier reef
of southern Belize. Second, Fv/Fm
values were
compared for M. faveolata from the inner lagoon
reef and outer barrier reef after exposure to controlled temperature
environments. Results suggest higher ambient seawater temperature and
number of hots days in the inner lagoon reef compared to the outer
barrier reefs. In situ Fv/Fm for Symbiodinium in M. faveolata were significantly
higher in the inner lagoon reef compared to the outer barrier reef. However, controlled temperature
experiments did not clearly show that inner lagoon reef counterparts
were less stressed physiologically when exposed to elevated seawater
temperature.
Thermal history and benthic
composition of reefs
In this study video transects analysis techniques were used to assess
changes in benthic composition of inner lagoon reefs and outer barrier
reefs in 2002, 2005, and 2007. The thermal history experienced by
corals in these two locations were also documented over the same period
for comparative purposes. Preliminary results suggest a link
between thermal regime and changes in benthic composition.
Assessing changes in skeletal
extension rates for corals from different subregions.
In this study we investigated variations in skeletal extension rates
for Siderastrea siderea
colonies from the outer barrier reefs (i.e., forereef and backreefs)
and nearshore reefs of southern Belize over approximately a century.
Preliminary results suggest declining skeletal extension rates in
forereef and backreef corals and increasing linear extension rates in
backreef corals over the same period. These trends may be related to
the different natural environmental conditions and/or anthropogenically
induced stressors within these three reef zones.
Future Research Interests and Directions
Compare in situ and
satellite-derived sea-surface temperature at larger spatio-temporal
scales (i.e., Mesoamerican Barrier Reef System).
Investigate and quantify the effects of multiple parameters (i.e.,
temperature, sedimentation, light, ph) on coral physiological response
over latitudinal gradients.
It has been suggested that coral physiological response may provide a
way for use to identify resistant and resilient
reef locations within marine protected areas. I am interested in
examining this
question through the development of in
situ and controlled
physiological experiments.
Use ecological modeling techniques to examine ways that would
effectively allow us to scale-up from the organismic level to scales
that would allow us to understand how coral populations,
communities, and ecosystems will adapt to what is now a general
consensus by scientist that our planet is changing.
Long-term monitoring to test the effectiveness of marine protected
areas in Belize by comparing benthic composition in coral reef systems,
including preservation zones (no take), conservation zone (catch and
release), general use zone (open access), and areas outside marine
protected
areas.