Caribbean
Coral Reef Ecosystems Program
Smithsonian Environmental Research Center
Smithsonian Marine Station
Smithsonian Tropical Research Institute
R/V URRACA
As we consider that the Smithsonian Marine
Science Network is much greater than the sum of its parts
- in both existing and potential research productivity, outreach
and education - an increased coordination of activities and
resource allocation will further this notion. Some SI scholars
feel that research is best advanced by curiosity and individually
prioritized objectives. At the same time, large-scale environmental
research often requires team approaches to gather big data
sets over enormous regions to address pressing problems in
the coastal zone.
The Marine
Science Network is well suited to support both approaches,
and simultaneous individual and collaborative inter-unit approaches
will work synergistically to advance marine research objectives.
These research elements form the foundation of expanded comparative
work in the future.
The
Caribbean Coral Reef Ecosystems Program (CCRE) – Belize
The Carrie Bow Cay Laboratory primarily serves to support
SI marine scientists' research projects on a year-round basis.
Hurricanes Fifi (1974), Greta (1978), and Hurricane Mitch
(1998) could not damage Carrie Bow Cay facilities the way
a devastating fire did in December 1997. Improved facilities
now include dry and wet labs, housing, generator, compressor,
small boats and scuba cylinders, and essential facilities
such as solar power, running-seawater system, and a weather
station.
Biodiversity, Morphology and Developmental Biology.
Studies cover the evolutionary range from microbes to manatees. Several
new toxic species of dinoflagellates that occur in blooms
(red tides) were identified based on cytological characteristics. A
study of benthic macroalgae was completed and will serve to
prepare an illustrated field guide. Earlier work on sponges
led to a multimedia computer key on mangrove sponges with
digitized underwater color photographs. The balance of
nutrient release and uptake by abundant sponges and bivalves
was found to be a decisive factor in the coupling of seagrass
and mangrove prop-root. Also in the mangrove, a sessile
ciliate (Zoothamnium) symbiotic with chemoautotrophic
bacteria was discovered and cultivated on sulfide-producing
substrates to measure reproduction and growth rates.
Species Interactions and Behavior. Study of a sponge-inhabiting
shrimp (Synalpheus spp.) confirmed its advanced social
structure for the first time in a marine animal. Morphological,
life-history, and phylogenetic analyses were also conducted
on fishes (labrids) and a new blenny (Acanthemblemaria)
was discovered.
Ecophysiology and Responses to Environmental Change.
Another experimental study shows how water flow affects coral
shape and growth rates, either by force and direction or by
nutrient distribution. Solar radiation, including UV
radiation, was measured on the Carrie Bow reef down to 39m
and in experiments has been found to affect rates of photosynthesis
and bleaching in symbiotic coral (Agaricia) and a sponge
(Calyx). A monitoring program has been established
to quantify the long-term temperature change effects on the
distribution and progress of black-band disease in reef corals.
Processes Linking Species and Environment. Mangroves
are a dominant coastal ecosystem throughout the tropics and
a major research focus at Carrie Bow Cay. A large multidisciplinary
team of researchers from SERC, NMMH, and several collaborating
institutions are studying the control of biocomplexity of
mangroves on small islands and along the mainland. The
program conducts manipulative experiments on nitrogen, phosphorus
and herbivores above the water, and also uses scuba to study
fouling communities of the subtidal mangrove prop-roots. Several
recent projects (Macintyre and Ruetzler, 2000) investigated
the Pelican Cays, an undisturbed and highly diverse group
of reef-mangrove islands 15km SSW of Carrie Bow Cay. The atoll-like
reef structure on which the cays are located is obvious only
from the air. Core drilling (to 15m) of the characteristic
reef-ridge system at Manatee Cay showed an open framework
construction made up of the branching coral Acropora cervicornis
and confirmed the original hypothesis that reef ridges are
all established on points of high karst relief on the underlying
pleistocene limestone. A. cervicornis has disappeared
from many Caribbean sites due to white band disease but here
it has been replaced by other coral (Agaricia spp.)
rather than by algae. High levels of herbivory by an echinoid
may be responsible for this difference.
Smithsonian
Environmental Research Center (SERC)- Chesapeake Bay
Global
Change. A major component of SERC’s research investigates
the environmental consequences of human-induced global change. In
addition to the “greenhouse effect” of global warming and
rising sea level, increased atmospheric carbon dioxide concentrations
(due to burning of fossil fuels) markedly affect the rates
of photosynthesis and carbon storage in plant communities. SERC
has the world’s longest running field experiments using chambers
to test the effects of CO2 increase on marsh plants
at the Rhode River site and on scrub oak communities at Kennedy
Space Center in Florida. Studies of harmful ultraviolet
solar radiation examine its effects on phytoplankton and macroalgae
in the Chesapeake Bay and in polar seas, where UV radiation
is intensified due to the formation of “ozone holes”. Damage
has been documented in the light-capturing ability of plants
and marine algae that support Earth’s food web. SERC
research on biogeochemical cycles show how carbon, nitrogen,
phosphorus, and silicate cycles are being altered by human
activities related to agriculture, forests and wetlands in
the coastal zone.
Ecological
Indicators at the Land-Sea Interface. Productivity
in coastal waters and estuaries is enriched by nutrient runoff
from the land. More than 70 percent of the world’s people
live in coastal zones. This concentrates development and water
pollution around bays and estuaries where the sea’s richest
fisheries are declining at alarming rates. By relating
nutrient discharge from the watershed to phytoplankton growth
in the estuary, SERC has gained new insights into the coupling
of land and sea. SERC’s watershed research in Chesapeake
Bay shows that excessive nutrient runoff from agricultural
crops and livestock stimulates overproduction of dinoflagellates
and other planktonic algae, which block light from reaching
aquatic plants and deplete oxygen. Excess nutrients can
cause algal blooms that are sometimes poisonous to fish and
humans. Other plankton studies alter the traditional
portrayal of bottom-up control of marine food chain production. Studies
of planktonic protistans show that single-celled parasites
may infect larger single-celled hosts. Epidemic outbreaks
of these parasites can cause plankton blooms to collapse,
effectively short-circuiting the food chain.
SERC has developed
new instruments to measure the quantity and spectral quality
of light penetration into coastal waters. These radiometers
monitor changes in underwater light in response to plankton,
particles and chemicals in the water column, and SERC research
shows how these measurements serve as good indicators of water
quality. Low light penetration limits the presence of
submerged aquatic vegetation in shallow water, and loss of
sea grasses has been a major loss of habitat for small fish
and crustaceans that support commercial fisheries.
SERC has explored
connections in Chesapeake Bay’s food web leading from plankton
production up to commercially important species of fish and
crustaceans, like the blue crab. One study examines
the value of the shoreline habitat as a refuge from predation
by large fish and blue crabs on small fish, grass shrimp and
juvenile crabs. SERC experiments show how this refuge
is being eliminated by shoreline development. Fisheries
in Chesapeake Bay have collapsed under over-fishing and environmental
degradation, leaving the blue crab as the only species with
a sustained commercial catch. Fundamental aspects of
blue crab behavior remain shrouded by the turbid waters in
which they live. To record movement and behavior of blue
crabs in their natural environment, ongoing SERC research
uses diving and innovative biotelemetry devices (Hines et
al., 1995; Wolcott and Hines, 1996) that transmit information
abut crab movement, feeding, fighting, and mating.
Marine Biological Invasions. Invading non-native
species introduced by human activities have disrupted ecosystems
around the world, causing major ecological changes and enormous
economic impacts. SERC is the national center for the
study of alien invasive species in coastal ecosystems. Presently,
ballast water in commercial ships is the major vector for
marine species introductions. Each day ocean-going vessels
transport millions of gallons of ballast water containing
live plankton. When ballast water is discharged, organisms
are released into new environments where, lacking natural
predators or other controls, they may become established and
wreak ecological havoc. SERC’s Invasions Biology Program
uses plankton nets to search for creatures stowing away in
ballast tanks of ships arriving in Prince William Sound Alaska
and the Chesapeake Bay, among other sites. The SERC Invasions
Biology Program uses scuba and other sampling methods to analyze
broad patterns of marine invasions and their ecological interactions.
Smithsonian
Marine Station at Fort Pierce (SMSFP)
Marine
Biodiversity. Many components of the SMSFP
program study marine biodiversity. SMSFP has developed
the Indian River Lagoon Species Inventory, which is accessible
electronically on the Internet. The Inventory is a relational
database that documents the 2,500 species of plants and animals
found in the Indian River Lagoon, making it the estuary with
the highest biodiversity in the Nation. The on-line database
includes summary information for a growing number of these
species, including images and data on their taxonomy, distribution,
life history, ecology, and special status.
Many other SMSFP
projects analyze the systematics, biogeography, natural history
and ecology of species in the coastal zone of Florida and
adjacent areas. “Caribbean Reef Plants” (Littler and
Littler, 2000) is a comprehensive field guide that contains
approximately 550 color plates and 2,750 black and white illustrations. It
features species descriptions, photographs, and morphological,
anatomical, and habitat/distributional data for nearly all
algal species found in the Caribbean. A study of the
diversity and phylogenetics of nemerteans is also in progress. These
are unsegmented, shallow-water worms ranging in size from
a few millimeters for interstitial forms to several meters
long for subtidal forms. Of the twenty species collected
from Florida, half are undescribed. Flatworm collections
from southeastern Florida and the Keys sampled 17 different
species, most of which are undescribed. Studies on the
biology and diversity of isopod crustaceans of the Indian
River Lagoon add to material that will be used for an illustrated
electronic field key to the isopods. Isopod sampling
stations included intertidal and subtidal mud, rubble, sand,
oyster beds, mangroves, algal turfs, live sponges, rotten
wood, macro-algal clumps and seagrass beds. Other crustacean
studies include classifications of xanthid (mud) crabs and
callianassid (ghost) shrimps. Resin casts of the burrows
of ghost shrimp were found to be highly complex, with numerous
perfectly coiled passages descending to the lowest points
of the casts. Speculation is that these coils stop predatory
eels from swimming into these passages, as such features in
prairie dog burrows have been proven to stop snakes from descending
into their burrows. Studies of genetic diversity in marine
populations are also underway. Distinct populations of
the crowned conch, a highly variable species, exist in Florida,
Alabama and the Yucatan Peninsula. DNA data is being
analyzed to clarify ambiguities in these populations. Deep-sea
snails called “slit shells” (Pleurotomariidae) are one of
the most ancient gastropod families being studied using Harbor
Branch Oceanographic Institution’s Johnson Sea-Link submersible
to depths of 3000 ft.
Life Histories
of Marine Species. Life
history studies are another major research theme at SMSFP. With
particular emphasis on reproduction, embryonic development
and larval biology, these studies focus on many groups, including:
sponges, copepods, molluscs, bryozoans, crabs, sipunculans
(peanut worms) and echinoderms. The SMSFP research vessel
Sunburst is used to sample larval stages in the Gulf Stream
offshore, while diving and other studies sample larval stages
passing through inlets to the Indian River Lagoon. Recent
studies of crab larvae coming through the inlets recorded
numbers of two dozen species’ megalopae settling each day
for 15 months continuously, including during a direct hit
by a hurricane. Other larval studies provide information
about control and cues to metamorphosis. Still others
measured depth distribution and diversity of cephalopods (squids
and octopuses) in the blue waters of the Gulf Stream. Recent
experimental studies determine interactions in complex life
cycles of trematode parasites that infect birds, snails, and
fish.
Ecosystems. Ecosystem studies at SMSFP have
focused on various reefs (including corals, oysters and cochina
shell), sea grasses, and soft benthos. Presently, ecosystem
studies are focused on the role of nutrients and herbivores
in regulating the biocomplexity of mangroves along the Indian
River Lagoon. Experiments use fertilizer treatments and
cages to determine interactive effects of nutrients, crabs’
burrowing, and insect herbivores. Long-term studies involve
multi-year data sets to document fluctuations in ecosystem
processes and population dynamics. For example, decadal
studies of foraminiferan populations in soft sediments of
the Indian River Lagoon measure marked changes in species
composition, abundance and stability of these important benthic
protists. At the same time, population and species diversity
of planktonic ciliates, dinoflagellates, and other protists
are being tracked in the water column of the Lagoon.
Smithsonian
Tropical Research Institute (STRI) – Republic of Panama
Inter-Ocean
Comparisons.
STRI’s Marine Environmental Sciences Program (MESP) collects
and analyzes fundamental oceanographic information that provides
critical information for studies such as El Niño and coral
bleaching. The Panama Paleontology Project in Bocas del
Toro seeks to record the history of the divergence between
the two oceans over the last 10 million years, and the evolutionary
response of marine organisms to these changes. Results
from this project are the geological reconstruction of the
closure of the Isthmus of Panama 3 million years ago, and
the discovery of a major extinction event in the Caribbean
about 2 million years ago. Through a combination of molecular
and paleontological information, STRI’s molecular evolution
program has developed a model system for determining the rate
at which organisms diverge genetically through time (Panama
molecular clock). This allows for the phylogenetic reconstruction
of marine life elsewhere in the world.
Tropical Instability.
STRI’s marine research has clearly shown that tropical marine
environments are highly dynamic on many temporal scales. Perhaps
the most dramatic revelation of long-term major changes was
the demise of the long-spined sea urchin (Diadema)
throughout the western Atlantic (Lessios et al, 1984;
Lessios, 1995). Apparently due to a disease originating
near the mouth of the Panama Canal in 1983, 95% of these once
abundant organisms disappeared over the course of two years.
Notwithstanding the high reproductive output of this urchin,
recovery has largely failed to occur and many overfished reefs
throughout the Caribbean have been smothered under algae freed
from the urchin’s grazing. This diving research showed
how over-fished reefs persisted for years with high coral
cover prior to the urchin die-off, but then rapidly succumbed
to the decimation of this single keystone species, showing
that synergy between multiple stresses on marine environments
can have unpredictably severe consequences. The sea urchin
saga also demonstrates how even extraordinarily abundant organisms
are potentially vulnerable to rapid elimination by diseases
that combine the lethality of Ebola with the contagion
of the common cold.
Marine environments
are also subject to man-made disasters in contrast to the
urchin epidemic, which was a natural event. The escape
of 60,000-100,000 barrels of oil into the mangroves and reefs
of Bahia Las Minas (Caribbean) has had unexpectedly prolonged
effects (Jackson et al 1989). Oil seeps into the
sediments around mangroves and returns to coat the coral reefs
year after year as heavy rainfalls (exacerbated by the effects
of deforestation) slowly wash it out. The skeletons of
corals record the history of acute disasters, as well as chronic
stresses, and x-ray analyses inspired by the oil spill document
a worrying decline in coral growth over the past century.
Marine Biodiversity. Corals
are the building blocks of coral reefs and are renowned for
the diversity of organisms that they shelter. STRI’s
studies have revealed that marine tropical environments contain
4-5 times more species on average than has been generally
realized. The most abundant and best-studied coral “species”
(Montastrea spp.) of the Caribbean is in fact a complex
of at least three species (Knowlton et al, 1992). Even
more surprisingly, these species each host a diverse array
of symbiotic algal partners, so that the combinatorial diversity
of Caribbean reefs is an order of magnitude greater than previously
assumed. The ecological importance of this diversity
was sharply highlighted during an episode of coral bleaching
caused by a Caribbean-wide temperature increase in the summer
of 1995. Only certain corals and certain parts of corals
bleached and the pattern could be predicted by knowing which
algae occurred where (Rowan et al, 1997). Thus
basic research on patterns of biodiversity have led to important
insights into the likely consequences of global warming.
Biotic diversity
is expressed at many levels, and one of the most fascinating
is animal behavior. Patient observation using scuba has
revealed many surprising details of how marine organisms function. Transmitters
attached to the backs of sea snakes show that these creatures
can spend up to 200 minutes at depths down to 50m. Identification
of fishes throughout the eastern tropical Pacific has contributed
significant biogeographical and distributional data (Allen
and Robertson, 1994). Decoding the meaning of color change
in squids has led to new appreciation for the communicatory
complexity of these organisms.
Reproduction
and Recruitment. For
many marine organisms reproduction depends on several steps:
the release of eggs and sperm into the sea (where fertilization
takes place), the development of a larva from the fertilized
egg, and the successful passage from the larval to the adult
stage. Some of these stages occur only sporadically and
at night. Mass spawning events, in which hundreds of organisms
release eggs and sperm simultaneously, have been documented
in Panamanian corals and seaweeds. For many corals, the
entire year’s reproduction is compressed into one or two days
about eight days after the August full moon. Recently a
Smithsonian scientific diver made the surprising discovery that
many green seaweeds also spawn in synchrony just before sunrise
(Clifton, 1997).
STRI pioneered studies of the bizarre sex life of reef fishes,
where sex change and sex role reversal appear to be the norm
rather than the exception, because they maximize the reproductive
success of individual fish. Parrot fishes spawn regularly,
every day at sunset. But what happens to their larvae,
which can spend a month floating in the ocean before settling
onto a reef, is less well understood. Giant underwater
light boxes are being used to trap larvae and measure the
rate at which different species recruit onto reefs. Fish
collected from around the Caribbean show, through molecular
data, that larvae often travel long distances before settling
down to a more sedentary adult life.
Research
Vessel URRACA
Built in 1987 by Lifeline Ship Construction in England,
the R/V URRACA is based in the Republic of Panama and
has been operated by the Smithsonian Tropical Research Institute
since 1994. The overall length of the vessel is 96.0
ft with a 22 ft beam. The navigational draft is 8.5
ft and full load displacement is 124 tons. The vessel's
molded fiberglass hull and aluminum superstructure has a waterline
length of 81.3 ft. The stern A-frame has a lifting capacity
of 5,000 lbs. 4 meter and 5 meter rigid hull inflatables
are available to support scientific diving operations.
The URRACA, with a crew of 5, can accommodate scientific
parties of up to 9 in comfort. She has a range of of
4000 miles and 30 days endurance. For more information
contact Pierre Fuentes: fuentesp@naos.si.edu
Literature Cited
Allen, G.R. and
D.R. Robertson. 1994. The Complete Divers’ and Fishermen’s
Guide to Fishes of the Tropical Eastern Pacific.
University of Hawaii Press. 332 pp.
Clifton, K.E.
1997. Mass spawning by green algae on coral reefs. Science
275: 1116-1118.
Jackson, J.B.C.,
J.D. Cubit, B.C. Keller, V. Batista, K. Burns, H.M. Caffey,
R.L. Caldwell, S.D. Garrity, C.D. Getter, C. Gonzalez, H.M.
Guzman, K.W. Kaufmann, A.H. Knap, S.C. Levings, M.F. Marshal,
R. Steger, R.C. Thompson, and E. Weil. 1989. Ecological
effects of a major oil spill on Panamanian coastal marine communities.
Science 243: 37-44. Hines,
A.H., T.G. Wolcott, E. Gonzalez-Gurriaran, J.L. Gonzalez Gurriaran
and J. Freire. 1995. Movement patterns and migrations
in crabs: Telemetry studies of juvenile and adult behavior
in Callinectes sapidus and Maja squinado.
J. Mar. Biol. Assoc. U.K. 75: 27-42.
Knowlton, N.,
E. Weil, L.A. Weigt, and H.M. Guzman. 1992. Sibling
species in Montastrea annularis, coral bleaching
and the coral climate record. Science 255: 330-333.
Lessios, H.A.
and I.G. Macintyre (eds.) 1997. Proceedings of the 8th
International Coral Reef Symposium (Vols. 1 and 2). Smithsonian
Tropical Research Institute, Republic of Panama. 2119
pp.
Lessios, H.A.
D.R. Robertson and J.D. Cubit. 1984. Spread of
Diadema mass mortality throughout the Caribbean. Science
226: 335-337.
Lessios, H.A.
1995. Diadema antillarum 10 years after
mass mortality: still rare despite help from a competitor.
Proc. R. Soc. Lond. B 259: 331-337.
Littler, D.S. and M.M. Littler. 2000. Caribbean
Reef Plants: An Identification Guide to the Reef Plants
of the Caribbean, Bahamas, Florida and Gulf of Mexico.
Offshore Graphics, Inc., Washington, D.C. 542 pp.
Macintyre, I.G. and K. Ruetzler (eds.) 2000. Natural
History of the Pelican Cays. Atoll Res. Bull. Nos. 466-480.
National Museum of Natural History, Smithsonian Institution,
Washington, D.C. 333 pp.
Rowan, R., N.
Knowlton, A. Baker, and J. Jara 1997. Landscape ecology
of algal symbionts creates variation in episodes of coral
bleaching. Nature 388: 265-269.
Ruetzler, K and
I.G. Macintyre (eds.) 1982. The Atlantic Barrier Reef
Ecosystem at Carrie Bow Cay, Belize. 1: Structure and
Communities. Smiths. Contrib. Mar. Sci. 12: 539
pp.
Wolcott,
T.G. and A.H. Hines. 1996. Advances in ultrasonic biotelemetry
for animal movement and behavior: the blue crab case study.
In: Lang, M.A. and C.C. Baldwin (eds.). Methods
and Techniques of Underwater Research. Proceedings of the
American Academy of Underwater Sciences, Smithsonian Institution,
Washington, D.C. Pp. 229-236.
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