PT20 Ecotoxicology of Tropical Aquatic Environments
Exhibit Hall
8:00 AM - Tuesday
(PT288) Effects of globally transported African dust to Caribbean marine ecosystems.
Carr, R.1, Nipper, M.2, Garrison, V.3, Griffin, D.3, Smith, G.4, 1 USGS, MERS, Corpus Christi, TX, USA2 TAMU-CC, Corpus Christi, TX, USA3 USGS, St. Petersburg, FL, USA4 USC-Aiken, Aiken, SC, USA
ABSTRACT- Widespread mortality of hermatypic corals throughout the Caribbean Region has been well documented in numerous studies in the past thirty years. Although the increasing loss of live coral and reef structure is of immediate concern, more serious and puzzling are: 1) the lack of recovery of damaged reefs; 2) the wide geographical distribution of diseases in coral reef organisms; 3) the apparent increase in types of diseases; and 4) the increase in mortality from disease. It has been proposed that the hundreds of millions of tons of dust transported annually from the African Sahara to the Americas via the Saharan Air Layer may be a significant factor in coral reef decline and may be affecting other ecosystems in the hemisphere as well. Dust clouds may serve not only as a periodic source of nutrients for primary producers in nutrient-depleted oceanic waters, but may also serve as a medium for the global transport of microorganisms and chemical contaminants. A study is being undertaken to determine whether African dust collected in the Virgin Islands during dust events contains contaminants or microorganisms which could be toxic or otherwise harmful to resident corals and other coral reef organisms. Elutriates of dust samples collected using high volume samplers located in the Virgin Islands were toxic to sea urchin gametes and embryos. Additional dust samples from the Virgin Islands are being collected for toxicity testing and toxicity identification evaluation (TIE) studies. In concurrent studies, dust samples are also being analyzed for contaminants, as well as bacteria and fungi known to cause coral diseases. An update of the results from the ongoing toxicology study will be presented.
Key words: toxicity, African dust, coral disease, Caribbean