DOUCETTE 9633805 Understanding the relationship between environmental conditions and Harmful Algal Blooms (HABs) in coastal areas is essential for predicting blooms, protecting human health, and preventing economic losses. Recently, considerable interest has focused on Pseudo-nitzschia, a diatom genus in which some species produce domoic acid, a potent neurotoxin, causing, among other things, death or short-term memory loss (Amnesic Shellfish Poisoning; ASP). Preliminary data from the Louisiana coastal zone show that Pseudo-nitzschia spp. (including potentially toxic species) reach very high abundances every spring in the plumes of the Mississippi and Atchafalya Rivers, and high abundances occur frequently, but less predictably in a Louisiana estuary. The hypothesized link between HABs and eutrophication will be tested by 1) comparing the highly eutrophic shelf environment with the less eutrophic estuary and 2) examining changes in Pseudo-nitzschia preserved in cores taken from the shelf where increasing eutrophication over time is well documented. Through a combination of new sampling and analysis of archived samples, a nearly ten year record of Pseudo-nitzschia species composition at a shelf site and a four year database of species composition and toxin production at both the estuarine and shelf sites will be related to a suite of environmental factors measured at the same time. New biotechnological methods for measuring toxin concentration, using a competitive receptor binding assay, and identifying Pseudo-nitzschia species, using molecular probes, will be tested in comparison with other more standard methods. The new techniques were developed as rapid and accurate screening methods which will ultimately be used for a wide range of applications in both the public and private sectors. Using these methods as part of this research represents a mutually beneficial collaboration between academic and government researchers and private industry.
