11th ICRS Abstract book - Nova Southeastern University

Oral Mini-Symposium 16: Ecosystem Assessment and Monitoring of Coral Reefs - New Technologies and Approaches
16-46
Caribbean Shallow Reef Coral δ 15 n Variability Among Species And Depth
Kirby WEBSTER 1 , Steve MACKO 1 , Kiho KIM* 2
1 Department of Environmental Sciences, University of Virginia, Charlottesville, VA,
2 Department of Biology, American University, Washington, DC
Long-lived coral accumulate available nutrients as they grow, and have potential to
provide a temporally integrated view of environmental conditions. Nitrogen stable
isotope analysis has been a powerful tool for reconstructing inputs into aquatic
ecosystems. Although isotope analysis has typically been used to infer sources of N,
δ15N may also be used as a proxy for concentration of N and other inputs. However, use
of any one species for such a proxy will limit the spatial and temporal extent over which
the reconstruction can be addressed. Comparative analyses may be difficult if a species
which is common to one area or depth is not observed in the location of interest, or if the
proxy has seasonal variation. This study addresses the question as to whether a range of
closely related species of the same taxa can be used in this regard. Stable nitrogen isotope
analyses of Gorgoniidae family corals were measured to determine the variation among a
range of species and with increasing depth in the water column. Gorgonians are common
to many shallow reefs in the Caribbean and thus represent an excellent test organism over
which the observations at one location could then be extended to another location in a
different gorgonian species. Isotope analyses of axial surface skeletal material revealed
no significant variation in δ15N values within Gorgoniidae collected from the same reef
indicating that observations on species within this taxa are interchangeable. However, in
Pseudopterogorgia americana collected over a 9 m depth gradient, a significant variation
with depth was observed (r 2 = 0.54, p < 0.0001) suggesting that depth must be kept
constant across sampling locations. The results of this study, combined with knowledge
of general abundance and N-rich axial skeleton, support the hypothesis that gorgonian
corals are an ideal candidate species for use as environmental proxies.
16-47
Light Attenuation Measurements In Bermuda Reefs
Gerardo TORO-FARMER* 1 , Burton JONES 2
1 Ocean Sciences, University of Southern California, Los Angeles, CA, 2 Marine
Environmental Biology, University of Southern California, Los Angeles, CA
The implementation of low cost and effective methodologies for long term monitoring
programs in coral reefs is needed, especially in geographic areas where economic and
scientific resources are limited. Specifically, in-situ optical measurements can be utilized
to estimate light attenuation due to suspended particles from terrestrial runoff or
resuspension of bottom sediments from navigation activities near coral reef areas. Spatial
and temporal variations of light penetration and attenuation were estimated using two
different methods: water column hyperspectral radiometric measurements, and long term
deployments of low cost underwater light intensity logger sensors. These methods were
compared at stations across the north reef in the Bermuda Islands. Existing radiative
transfer models were also used to compare the observations from these sensors against
theoretical values. Variations in the diffuse attenuation coefficient were found among the
different stations and between seasons, suggesting temporal changes in the optical field
due to natural and possibly anthropogenic disturbances. Regardless of the intrinsic
differences between high end and low cost methodologies, the correct interpretation of
data from these light intensity loggers can facilitate and improve monitoring and
management of coral reef and other coastal ecosystems.
16-48
Mining ICON/CREWS Data Sets for Discovering Relationships between Environmental
Factors and Coral Bleaching
Marc BOUMEDINE* 1
1 University of the Virgin Islands, St. Thomas, Virgin Islands (U.S.)
In order to assist researchers in assessing the impact of climate change on coral reefs, NOAA
Integrated Coral Observing Network (ICON/CREWS) stations collect large amounts of in-situ
oceanic and atmospheric data in the Caribbean region. Local effects of environmental factors
such as sea temperature, wind speed and direction, light intensity, tides and water salinity on
coral reef bleaching are determined by expert system technologies. Since expert knowledge is
largely heuristic, the expert system knowledge base is constantly refined and enhanced as new
axioms, theories or rules of thumb become available. Since expert systems can not learn
independently, an approach to automatically extract new patterns and ultimately knowledge
from historical ICON/CREWS data sets is proposed. In this study, patterns have been extracted
from data sets generated by the Lee Stocking Islands (Bahamas) ICON/CREWS station from
the May 21, 2005 till December 31, 2005. The Apriori association rules algorithm generates
patterns in the form of rules such as: “if event ei occurs then event ej also occurs”. Frequent
patterns are observed between Pulse Amplitude Modulation (PAM) yield and light intensity,
such as photosynthetically active radiation (PAR). Additional relationships between PAM yield
and salinity, as well and PAM yield and wind speed are derived. In addition to rule generation,
two classifiers have been designed in an attempt to predict PAM yield values from
environmental factors. Our preliminary results are encouraging since more than 85% of the test
instances are correctly predicted with both neural network and decision tree algorithms. These
preliminary results suggest that data mining techniques are valuable approaches for
complementing existing coral bleaching predictive models.
16-49
The Reefpad: A Handheld Underwater Computer Aimed At Improving The Speed And
Accuracy Of In-Situ Monitoring Of Coral Reefs
Frederic CHARPENTIER* 1 , Peter GAYLE 2 , Bernadette CHARPENTIER 3
1 Duwatech, Ottawa, ON, Canada, 2 Center for Marine Sciences, Discovery Bay Marine Lab,
Discovery Bay, Jamaica, 3 Research an Development, Duwatech, Ottawa, ON, Canada
Coral reef monitoring is a labor and time-intensive process with inherent challenges related to
increasing spatio-temporal resolution. It requires the collection of various data ranging from
individual counts to photo surveys. The collected data needs subsequent transcription and
processing. The hardware used today to conduct coral monitoring ranges from pencils and slates
to photo cameras and other ad hoc instruments which are usually adequate but poorly
integrated. The ReefPad is a low-cost handheld underwater computing device specifically
designed to simplify in-situ work by decreasing data collection time while improving the
accuracy and quantity of the collected data. The electronic circuitry is housed in a 10 x 16.5
cms. acrylic cylinder rated to a depth of 70 meters. It houses a main computer based on an
ARM micro-processor, in addition to a PIC microcontroller, a number of sensors (depending on
variables being investigated) and a 10 cms. color screen. The basic sensor configuration
includes a 3-axis magnetometer and two dual-axis accelerometers. The device can also be
custom fitted with digital cameras, lasers, photometers, temperature sensors and RFID readers.
The accelerometers and the magnetometer allow the use of dead reckoning for underwater
navigation after an initial GPS calibration at the surface prior to the dive. The motion sensors
also allow the researcher to interact with the software using gestures thus eliminating the need
for buttons, keyboards or writing surfaces. The graphical user interface of the ReefPad was
specifically designed to facilitate immediate access to maps, hierarchical lists and referencing
software through simple hand motions. The software is configurable and designed to support
existing methodologies while decreasing collection times, increasing data accuracy and
broadening the investigative scope.
139