USGS Leetown Science Center Disease of Coral and Coral Reef Fishes

he occurrence of disease in coral reef systems is a growing T environmental crisis that threatens the biological diversity of the world’s oceans.

Coral Reef — Buck Island National Park The Department of the Interior and extensive loss of the sea urchin protects sensitive habitats (Diadema antillarum) was perhaps Massive fish kills in the northeast amounting to about 3,600,000 acres Caribbean within State waters of of coral reefs and other submerged Barbados, Trinidad, Tobago, lands. These reefs are important Guyana, Grenada, St. Thomas and ecosystems in 13 National Wildlife The Grenadines in 1999 were Refuges, 10 National Parks and in caused by septicanemic certain territorial waters such as the Streptococcus iniae; a serious Wake Atoll. bacterial disease of marine fishes. Many other reports of fish kills Over the past several decades, Coral Bleaching of Porites astreoides (normal on left—bleached on right) were often associated with there have been over 34 instances of poor water quality. documented mass mortalities These epizootics and other reports involving corals, sponges, urchins, one of the first well-studied of diseases of coral reef and mollusks or fish and there is some epizootics in the Caribbean. The associated fishes have shown that a direct evidence to suggest that the loss of this primary herbivore on variety of bacterial, viral and frequency of these marine coral reefs resulted in broad-scale fungal pathogens and several host- epizootics is increasing. These ecological change affecting many ectoparasite relationships directly mass mortalities often result in reef organisms, including the effect fish health. However, in significant shifts in coral associated fish communities. Other general there are few observations community structure. The sudden mass mortalities in staghorn coral of disease in coral reef fishes and (Acropora palmata), elkhorn coral consequently, little effort to (Acropora cervicornis) and turtle document associated bacterial and grass (Thalassia testudinum) in viral pathogens. Florida Bay may have likewise caused changes in marine fish communities. Scientists at the Leetown Science Center have developed The relationships between marine aquaculture and biodiversity and ecosystem experimental systems to explore function in coral reefs, including the characteristics and processes of the resistance to and resilience disease as it affects coral reef Preparation of Bacteriological Plates from disturbances, are unclear. organisms. Since August of 2002

U.S. Department of the Interior Printed on recycled paper LSC Fact Sheet U.S. Geological Survey March 2008 Current and Planned Research Activities • Investigate the role of reef connectivity in maintaining diversity. • Develop molecular techniques for the study of disease processes in live coral. • Develop molecular biomarkers indicative of coral health status. • Study the effect of herbicides (such as Atrazine) on corals, symbiotic dinoflagellates, Thalassia, and other reef organisms. • Determine if and how corallivorous reef fishes serve as vectors of coral disease.

scientists have capitalized on the storage and transport to the evolutionarily, and this allows them high-intensity natural light in our laboratory. This card-based to be identifed by polymerase chain greenhouse to develop several large sampling method allows room reaction (PCR), hybridization, and/or culture systems stocked with a range temperature storage of DNA samples antibody methods. A suite of assays of coral invertebrates and plant for years and eliminates problems that could be used to measure and species of interest. These systems with often-used low temperature assess the physiological status of are described in another USGS Fact storage and transport from remote these life functions in key coral Sheet (http://pubs.usgs.gov/ locations Further details can be species would be a useful fs/2004/3116). The success of the found in another Fact Sheet (http:// management tool for use in LSC laboratory systems is indicated www.coralreef.gov/library/pdf/ predictive modeling. by the diversity of species that they DOI%20bleaching%2011-06.pdf). support. Currently, the LSC systems To test this approach of maintain over 200 species of plants A current study, in conjunction biomarker identification, the and animals, including macroalgae, with scientists at the University of expression of several gene families submerged aquatic angiosperms the Virgin Islands is focused on was investigated to study the (true seagrasses), many types of understanding reef connectivity. molecular mechanisms functioning calcareous algae, mollusks (snails The genetics of two reef-building in the deep-sea coral, Lophelia and clams), echinoderms (seastars, corals (Acropora palmata and pertusa. In conjunction with other urchins, brittle stars), numerous Montastraea annularis) as well as a USGS scientists, and with the cnidarians (corals, anemones), commercially valuable reef fish, the support of the Minerals Management crustaceans, and an array of worms Nassau grouper, are being studied to Service, samples were collected of various phyla. determine how the dissemination of from a Gulf of Mexico site known as juveniles is influenced by ocean Visoca Knoll using the Johnson Sea- Research at Leetown focuses on currents. Another part of this study Link deepwater submersible . the relationship between reef is being conducted in the Leetown Utilizing advanced forms of organisms, pathogens, and greenhouse facility to test the effects polymerase chain reaction, four environmental factors. A major of dissolved organic carbon and previously unknown expressed genes bleaching event that occurred in the current flow on coral-associated were discovered by Leetown Caribbean in the fall of 2005 was bacterial flora. These experiments scientists that are associated with studied by USGS scientists in examine the possible influence of vegetative growth, division, gamete conjunction with the U.S. Park excess nutrients from runoff in the development, and skeletal Service. Importantly, non-invasive, production and/or exacerbation of biomineralization. non-destructive sampling methods coral disease. were developed by USGS scientists For more information contact: and employed to accomplish In general, the relationships of sampling needs and get statistically coral health to diseases are largely Frank Panek significant numbers with minimal unexplored and unknown. To USGS Leetown Science Center impact on the reef organisms. explore these relationships scientists 11649 Leetown Road Sterile, foam swabs were used to will develop molecular biomarkers Kearneysville, WV 25430 sample healthy and diseased coral indicative of coral health status. (304) 724-4431 or and material was transferred to Many important biological Visit us at: http://www.lsc.usgs.gov specially prepared “gene cards” for molecules are relatively conserved