US Coral Reef Initiative--US National Science Foundation
Coral Health and Monitoring Program
coral at aoml.noaa.gov
Wed Apr 17 06:49:55 EDT 1996
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To: coral-list
Subject: US Coral Reef Initiative -- US National Science Foundation
16 April 1996
To anyone interested:
Attached is a revised compendium that outlines many research and
related projects that were supported by the U. S. National Science
Foundation with Fiscal Year 1995 funding as part of the US Coral Reef
Initiative and as part of the US contribution to the International
Coral Reef Initiative.
Phillip Taylor, Director
Biological Oceanography
Division of Ocean Sciences
U. S. National Science Foundation
4201 Wilson Blvd.
Arlington, Virginia 22230 USA
prtaylor at nsf.gov
703-306-1587
16 April 1996
Directorate for Geosciences (lead)
Population Biology of Caribbean Octocorals
Daniel Brazeau, University of Florida
Fertilization success among sessile, marine invertebrates is a largely
unknown variable bridging those factors which field ecologists can measure
(fecundity, organism size, population abundance) and one often difficult
to estimate (reproductive success). Using the Caribbean octocoral Baiareum
asbestinum as a model animal, this project will examine temporal and
spatial variation in reproductive success for male and female colonies.
The research will test the specific prediction that female fertilization
success is directly proportional to the nearby abundance male colonies.
This information is crucial for understanding the abundance and growth of
invertebrate populations in coral reef ecosystems and will provide
important information for the successful restoration and management of
coral reefs worldwide.
The Role of Heterotrophic Dinoflagellates in Marine Plankton Dynamics:
Growth, Grazing Behavior and Bioluminescence Edward Buskey, University of
Texas
This study will examine the effects of food quantity and quality on the
growth, feeding and bioluminescence of several species of Protoperidinium.
Selective feeding of these pallium, feeding dinoflagellates (which capture
large food particles extracellualarly) and the role of sensory perception
in this selection process will also be examined. In addition, the study
will determine the abundance of heterotrophic dinoflagellates in the
western Gulf of Mexico, and examine the relationship between growth rate
and bioluminescence capacity for field collected Protoperidinium incubated
at ambient food concentrations.
Hydrodynamic Forcing of Metabolism of Coral Reef Algal Communities Robert
Carpenter, California State University Northridge and Susan Williams, San
Diego State University
The current paradigm explaining how coral reefs maintain high biomass of
organisms and extremely high rates of gross primary productivity is that
tight recycling of nutrients and organic matter occurs within the reef
resulting in zones of net autotrophy alternating with zones of net
heterotrophy. Autotrophic upstream communities are thought to support
downstream heterotrophic assemblages with the overall balance resulting in
ecosystem P/R ratios near unity. According to this paradigm, coral reefs
are not coupled significantly to the surrounding oligotrophic ocean.
Recent studies suggest that coral reefs may be much more dependent on
hydrodynamic processes than currently believed. Although nutrient
concentrations of tropical waters are very low, an enormous volume of
water is advected across the reef and could result in a large flux of
nutrients to benthic primary producers. The major upstream autotrophic
zone is the reef flat where algal turf assemblages are responsible for the
majority of primary productivi ty. Previous work has demonstrated that
rates of primary productivity and nitrogen fixation of algal turf are
affected significantly by water flow speed. Furthermore, flow measurements
on one reef suggest that algal canopy height significantly alters the
local hydrodynamic regime and as a result, metabolic processes of algal
turfs may be diffusion-limited for a significant proportion of time. This
project will test the hypothesis that rates of primary productivity and
nitrogen fixation of coral reef algal turfs are diffusion-limited.
Measurements of the flow environment on a reef flat will be made and used
to estimate the degree to which algal turfs varying in canopy height are
diffusion-limited. The project will then move on to test hypotheses about
the specific factors that result in diffusion- limitation. The results of
this project should fill a gap on empirical measurements of water flow in
coral reef environments and how water flow affects algal metabolism. The
results of this research may lead to a si gnificant paradigm shift in
understanding how coral reefs function. Demonstration that reefs are open
ecosystems that are strongly coupled to the surrounding ocean environment
would have important implications for predictions of the effects of global
climate change on these unique ecosystems.
Recent Variability in the Intertropical Convergence Zone of the Western
Atlantic: Seasonal Multicentury Reconstructions from Venezuela Corals
Julie Cole, University of Colorado
This project will examine stable isotopes in corals collected off
Venezuela to look for evidence of changes in ocean circulation and
temperature which may correlate with rainfall patterns in Brazil and
sub-Saharan Africa. If so, the coral record can be used to extend rainfall
records to prehistoric times, in order to discern cyclic or long-term
changes. The project also implicitly tests assumptions about the role of
cross- equatorial heat transport in controlling tropical Atlantic climate.
The Record of ENSO in the Warm Pool of the Western Pacific: Multi-century
Reconstruction from the Geochemistry of Long-lived Corals Julie Cole,
University of Colorado
The western Pacific warm pool provides a major source of water vapor and
energy to the global atmosphere and is a "center of action" for the El
Nino/Southern Oscillation (ENSO) system, whose signal permeates the global
record of interannual climate variability. ENSO warm extremes originate
from the region, and the western Pacific convection anomalies associated
with ENSO propagate climate variability throughout the tropics and the
world. This award supports a project that will reconstruct multi-century
records of variability in the ocean/atmosphere of the western equatorial
Pacific, using geochemical records from the skeletons of long-lived
corals. The study will extend the limited record to ENSO to span the past
few centuries along an equatorial transect from the region of the date
line into the heart of the western Pacific warm pool. The resulting
records will provide a new understanding of long-term temporal and spatial
variability of ENSO and its relation to variations in the western Pacific
warm pool an d to external forcings, including the regional response to
the Little Ice Age. The proposed paleoclimatic study will place the
TOGA/COARE observations in a long-term perspective and delineating the
range of natural variability that models must aim to simulate.
Population and Community Dynamics of Corals: A Long Term Study. Joseph
Connell, University of California
The objectives of the present project are several: 1) To extend the
detailed long-term monitoring of ecological communities of corals and
algae on the Great Barrier Reef, Australia which has been carried on
continuously over the past 30 years, the longest such study on any coral
reef; 2) to expand the study to include sites on two nearby reefs, and
additional replicate sites on Heron Reef; 3) to analyze spatial patterns
and dynamics of corals and algae at several scales, from centimeters to
tens of meters, both during the course of colonization of patches (opened
by disturbances) and after most of the surface has become crowded by many
colonies. These analyses should reveal the long-term effects of
interactions that may be crucial in determining how natural communities
are structured; 4) to test with controlled field experiments some
hypotheses about mechanisms: a) that produce the unique species
composition of corals at the Inner Reef Flat site, b) that cause
contrasting patterns of algae after disturbances , and c) that determine
precisely how each colony affects its neighbors; 5) to build mathematical
models and computer simulations of the dynamics of these populations and
communities of corals and algae: a) to investigate the influence of past
and present conditions on future changes, b) to characterize temporal and
spatial dynamics, and c) to test hypotheses about the consequences of
these dynamics to the community. The models will be also used to asses the
degree to which community structure and dynamics may or may not be
influenced by details of spatial relationships. The field methods will use
the standard sampling techniques used over the past 30 years, to assure
continuity in the long-term data base. The experimental methods, using
coral transplanting and cages to exclude larger herbivores, have also been
used before in this study and are well- established. Larval choice
experiments and new recruit transplants have been carried out successfully
by the co- investigators elsewhere on the Great Barrier Re ef.. The
significance of this proposed research to the advancement of knowledge is
that: 1) it deepens the general knowledge of how natural communities of
corals and algae (the dominant sessile organisms on tropical and
sub-tropical reefs), are assembled and structured in the face of changes
in their environment over extended periods of time; 2) it reveals some of
the mechanisms that link the environment with these community changes, and
how both vary over short and long time periods and between small and
larger spatial scales; and 3) it helps to predict the effect of
environmental changes, including those caused by human activity, on these
natural communities.
Ribosomal DNA Sequences in Marine Yeasts: A Model for Identification and
Quantification of Marine Eukaryotes Jack Fell, University of Miami
Using molecular techniques for rapid and accurate determination of
community structure, this research will determine fungal biodiversity and
population biomass in tropical caostal ecosystems (principally mangrove
ecosystems) of two distinctly different groups of micro-fungi: the
basidiomycetous yeasts and the oomycetous genus Halophythophora. Both
groups have important roles in detrital based food webs. The research
program will include laboratory and field studies. Laboratory studies will
complete the data bank of know species as a basis for determining
community structure in the field. New procedures will be developed with
preliminary emphasis on quantitative PCR (QPCR) using laser detected
infrared labeled primers. Field research will center on reef and mangrove
habitats. Using a combination of classical microbial techniques and
molecular methods, the community structure and relative abundance of known
and unknown culturable fungi species will be determined. The identity of
these species will be ascertain ed by automated DNA sequence analysis and
nucleotide alignment with the data bank. Species-specific regions will be
located and primers developed to test the accuracy and sensitivity of PCR
techniques in estimating community structure. Through the use of PCR and
QPCR, the occurrence of unculturable species and population densities will
be estimated. The techniques developed in this research can be applied to
population analyses of other micro- or macro-eukaryote communities.
Bleaching of Symbiotic Algae (Zooxanthellae) and their Invertebrate Hosts:
Causes and Mechanisms William Fitt, University of Georgia
Bleaching, the loss of symbiotic dinoflagellates("zooxanthellae"
hereafter) of their pigments, of reef corals and other invertebrates has
become a world-wide problem in tropical marine ecosystem, linked by some
researchers to global warming. The results of bleaching have potentially
devastating environmental, ecological and economic effects in the
Caribbean, IndoPacific, an other tropical marine areas. Though there is
some experimental work showing involvement of both higher than average
temperature and light, the mechanisms involved in bleaching are not well
understood this project will test three hypotheses. 1. Bleaching in nature
is caused by high temperature stress coupled with high energy blue light
(and possibly UV-A between 380-400nm). Preliminary evidence shows that
while high temperature alone will induce bleaching, natural light exposure
during high temperature treatment exacerbates the effect by lowering the
temperature threshold and time to bleaching at a given temperature. this
study will determ ine which component of light is responsible for this
effect and the mechanisms of action. Early theories on bleaching had light
playing a major role, but experimental evidence has not yet supported this
contention. Potentially harmful chemical alterations associated with high
energy wavelengths of blue light (and possibly some near-blue wavelengths
of UV-A, that are not adsorbed by UV-protecting pigments found in corals)
are not only consistent with field observations of bleaching, but are also
supported by both laboratory and field-based preliminary experiments. 2.
The mechanisms of temperature-light induced bleaching involves the
irreversible dissociation of the chlorophyll-protein associations in the
chloroplast. The harmful effects of high temperatures and light on algae
include the irreversible separation or inactivation of the
chlorophyll-protein complexes associated with reaction centers in the
chloroplast. Electron transport activity and eventually carbon fixation
decrease markedly. 3. High light and temperatures cause decreases in
"protective" pigments which absorb ultraviolet light. The role of
different wavelengths of light in conjunction with high temperature in
determining concentrations of UV- screening pigments will be determined as
well as their relationship with photosynthetic rates. These hypotheses
will be tested using cultured and freshly isolated zooxanthellae, and
intact hosts both in the laboratory and in field-based experiments.
El Nino Impacted Coral Reefs In The Tropical Eastern Pacific Secondary
Disturbances, Recovery and Modeling of Population and Community Responses.
Peter Glynn, University of Miami
This research will continue a long-term study that has focused on
ecological disturbances to eastern Pacific coral reefs that accompanied
the sever and historically unprecedented 1982-83 El Nino-Southern
Oscillation (ENSO). The study involves international collaboration with
host- county research teams and primary field sites in Costa Rica, Panama,
and the Galapagos Islands (Ecuador), areas heavily impacted by the 1982-83
ENSO. Dr. Glynn will lead the research to continue (a) with the physical
and biotic monitoring of eastern Pacific coral reefs initiated in the
early-mid 1970s, (b) investigating the responses of different coral
species to ENSO stressors, (c) studying coral reproductive ecology as it
relates to recruitment success, and (d) documenting coral community
recovery. New research directions include (e) remote sensing, which will
attempt to link coral bleaching/mortality with local and global scale sea
surface temperatures by means of synoptic and repeated measurements, and
(f) modeling of coral pop ulation and community dynamics based on
mechanistic relationships between temperature, predation, coral growth,
and survivorship derived from field monitoring and experimental results.
Because important secondary disturbances are still occurring and reef
recovery has been slow, it is necessary to continue this study in order to
understand the variety of changes involved and the full impact of a major
disturbance on eastern Pacific coral survival and reef building. We are
hopeful that ENSO warming disturbances can provide some insight to the
probable changes in coral reefs worldwide if projected global warming
causes repeated and/or protracted sea temperature increases comparable to
the 1982-83 ENSO.
Quantitative Aspects of Prey Chemical Defenses
Mark Hay, University of North Carolina
This project will extend the PI's current investigations on chemical
mediation of seaweed-herbivore and invertebrate-predator interactions to
include: (1) complex interactions of prey nutritional value with chemical
and structural prey defenses, (2) an understanding of how larval and spore
defenses differ from those of the adult, and why (exposure to different
consumers?, increased exposure to UV without adult structures that provide
shade?, etc.), and (3) the role of learned aversion by vertebrate versus
invertebrate consumers in affecting both prey and consumer dynamics.
Because benthic seaweeds and invertebrates play a trophically and
ecologically important role in tropical and sub-tropical near-shore
communities and are rich sources of novel secondary metabolites that
function as defenses against consumers and have potential applications as
pharmaceuticals, agrochemicals, and growth regulating substances,
understanding how these organisms respond chemically to ecological and
environmental threats can pro vide fundamental information about how
marine systems function, and can suggest strategies for applied uses of
marine natural products.
Broadcast Spawning and the Population Ecology of Coral Reef Animals Howard
Lasker, State University of New York
The literature on marine benthic ecology and evolution has generally
ignored fertilization rates as an important factor in the life histories
of benthic species, many which are important resource species. These rates
have implicitly been assumed to be uniformly high and thus not a terribly
significant factor in the establishment of the adult populations. There
are now a number of data sets which raise doubts about the validity of
that assumption. The research will determine rates of fertilization among
natural populations and will explore some of the factors controlling these
rates in reef communities. Using the Caribbean gorgonian, Plexaura A, as a
model system Drs. Lasker and Coffroth will determine rates of
fertilization of eggs released in synchronous spawning events. Plexaura A
is clonal and often has skewed ratios of male and female colonies on
different reefs. This will enable comparison of rates from reefs which
differ in current regime and in the density of male colonies. Using random
amplified poly morphic DNA (RAPD) from individual planulae larvae, they
will conduct paternity analyses, determine the proportion of
fertilizations attributable to specific male clones, and determine the
effects of clone size and distribution on fertilization. If rates are low
and are affected by factors such as population density, then it will be
necessary to incorporate fertilization rates in analyses of benthic
population animal dynamics and evolution.
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