Collaborative Research: Pseudo-Nitzschia Species, Toxin Production, and Eutrophication in the Northern Gulf of Mexico: Past and Present

杜塞特9633805了解环境条件与沿海地区有害藻华之间的关系，对于预测赤潮、保护人类健康和防止经济损失至关重要。最近，人们对拟硝化藻产生了相当大的兴趣，这是一种硅藻属，其中一些物种产生软骨藻酸，这是一种强有力的神经毒素，除其他外，会导致死亡或短期记忆丧失(健忘性贝类中毒；ASP)。来自路易斯安那州海岸带的初步数据显示，伪菱形藻。(包括潜在有毒物种)每年春天在密西西比河和阿查法里亚河的羽流中达到非常高的丰度，并且经常出现高丰度，但在路易斯安那州的河口却难以预测。赤潮和富营养化之间的假设联系将通过1)比较高度富营养化的陆架环境和较少富营养化的河口进行检验，以及2)检验从陆架采集的岩芯中保存的假性硝酸盐的变化，在那里，随着时间的推移，富营养化的增加被很好地记录下来。通过新的采样和对存档样本的分析相结合，一个搁架地点近十年的伪菱形藻物种组成记录和河口和搁架地点的物种组成和毒素生产的四年数据库将与同时测量的一系列环境因素有关。将与其他更标准的方法进行比较，测试使用竞争性受体结合分析来测量毒素浓度的新生物技术方法，以及使用分子探针识别假硝化细菌物种的新方法。这些新技术被开发为快速和准确的筛查方法，最终将在公共和私营部门的广泛应用中使用。使用这些方法作为这项研究的一部分，代表了学术和政府研究人员与私营行业之间的互利合作。

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.