USGS Columbia Environmental Research Center Project: Anthropogenic Organic Contaminants on Coral Reefs - Global Atmospheric Deposition or Local Sources?


Statement of Problem
: The aquatic toxicology of numerous chemical contaminants such as PAHs, organochlorines (e.g., DDT), and metals has been studied extensively. These compounds have been found to act as neurotoxins, narcotics, endocrine disruptors, mutagens, carcinogens, or to affect growth and reproductive processes (Rand 1995). Concentrations as low as parts per trillion of some contaminants have been shown to produce significant effects in marine organisms and humans. The effects of atmospherically transported and deposited chemical contaminants on coral reefs at the molecular, cellular, organismal and system level are essentially unknown. The USGS global dust research group has proposed the following questions for investigation: 1. Are chemical contaminants transported with African or Asian dust impairing immune response and/or reproduction in coral reef organisms? 2. Are they interfering with the ability of coral larvae to settle and grow or with the survival of young corals? 3. Are effects at the cellular or molecular level affecting metabolism, reproduction, calcification or immunocompetency? 4. What synergistic, cumulative or threshold effects are at work (Garrison et al. 2003)? The implications of atmospheric transport and deposition of chemical contaminants on coral reefs and other ecosystems may be substantial. Before the research questions enumerated above can be addressed, we first need to know: 1) what chemical contaminants are transported in African and Asian dust systems and in what concentrations; 2) what chemical contaminants coral reef organisms are exposed to and in what concentrations in the reef environment. The global dust research team (including Garrison) is currently working to identify and quantitate the synthetic organics transported in the atmosphere. This proposal seeks funding to identify the synthetic organic chemical contaminants present in seawater (dissolved) and sediments (sorbed) on the reef and in what concentrations (Echols et al. 2000). The findings will be analyzed in conjunction with the findings from the atmospheric study so that we can determine: 1. the likely source(s) (atmospheric/oceanic vs. local) of the contaminants; 2. the organic chemical contaminants, phase distribution and the concentrations to test in future marine organism ecotoxicology research. Knowing the kinds of contaminants and probable sources will be of value to marine resource managers of the State of Hawaii, Territorial Government of the Virgin Islands, National Park Service and Fish and Wildlife Service in developing and evaluating conservation management strategies. The findings will also be of interest to molecular biologists investigating the molecular and cellular mechanisms involved in disease in coral reef organisms. This research project will integrate directly with the large-scale study of globally transported contaminants in dust air masses and extend our understanding of the ocean-atmospheric processes linking the world deserts to the reef environments in two oceans. Specific research questions to be addressed: What synthetic organic chemicals are Caribbean and Pacific coral reef organisms exposed to and in what concentrations? If contaminants are present: are they found in seawater and/or reef sediment; are they detected only during dust events, or during both dust and non-dust periods?

Objectives: 1) to identify the synthetic organic chemicals in the coral reef environment (seawater and reef sediment); 2) quantify the concentrations of the contaminants; and, 3) compare data from upcurrent sites to island-influenced sites and between dust and non-dust periods to determine whether the source is local and/or distant.
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