Life Sciences Commons^™

The Effects Of Aqueous Atorvastatin On Steroidogenesis Of Xenopus Laevis At Environmentally Relevant Concentrations, Jeremy Johnson

Master's Theses

Statin drugs are a class of drug that work to reduce endogenous production of cholesterol by competitively inhibiting 3-hydroxy-3-methyl-glutaryl-CoA reductase (Hmgcr) thus inhibiting production of mevalonic acid in the mevalonate pathway. Atorvastatin (Lipitor) is one of the most widely prescribed statin drugs and contamination of wastewater effluent is a growing environmental concern because of the potential to interfere with steroidogenesis in wildlife. Amphibians may be particularly susceptible to the effects of atorvastatin contamination because of their highly permeable integument. I used an amphibian model, Xenopus laevis to test the hypothesis that chronic exposure to low concentrations of atorvastatin …

Molecular Responses To Deepwater Horizon Oil Spill Contaminants In Estuarine Fish, Elizabeth Jones

Dissertations

The 2010 Deepwater Horizon (DWH) oil spill resulted in the oiling of approximately 2100 km of shoreline. During that time, resident organisms had to contend with the effects of multiple contaminants and suboptimal environmental conditions. This research examines the molecular effects of DWH oil spill contaminants in estuarine fish (CyprinodonvariegatusandFundulusgrandis) across multiple life stages, contaminant concentrations, and in conjunction with environmental stressors.

Our results indicate that:

1. Oil elicits substantial transcriptional effects across life stages in C. variegatus. In adults, exposure to low concentrations of oil and dispersant results in transcriptional effects related …

Detection Of Adsorbed Chlordecone On Microplastics In Marine Sediments In Guadeloupe: A Preliminary Study, Fidji Sandre, Charlotte R. Dromard, Karyn Le Menach, Yolande Bouchon-Navaro, Sébastien Cordonnier, Nathalie Tapie, Hélène Budzinski, Claude Bouchon

Gulf and Caribbean Research

Plastic pollution in the oceans is recognized as a worldwide problem. Since the 1950s, the production of plastics has been increasing and the first reports of microplastics (particles < 500 μm) in the marine environment began to appear in the 1970s. These particles represent a growing environmental problem due to their dispersion in seawater and marine organisms. Additionally, microparticles in general can adsorb pollutants that will then become bioavailable to organisms by being desorbed during digestion, which could be an important pathway for the contamination of organisms. In Guadeloupe and Martinique, an organochlorine pesticide called “chlordecone” was used from 1972 to 1993 in banana plantations and this very persistent pollutant contaminates soils, rivers, and coastal marine areas and accumulates in marine foodwebs. To examine these issues, we had two goals: 1) to assess the contamination of marine sediments by microplastics surrounding Guadeloupe; and 2) to determine the ability of microplastics to adsorb chlordecone, as has been demonstrated for other organochlorine pollutants. To do so, marine sediments were collected in triplicate from 12 sites in coral reef environments around the island. Microplastics from each sample were then enumerated by size, color and shape under a binocular microscope. The results indicate that microplastics are found in all the studied sites and that their distribution could be linked to marine currents or proximity to areas of significant human activities (port activities, agglomeration, etc.). Finally, our preliminary results indicated that chlordecone could be adsorbed onto microplastics, with a concentration ranging from 0.00036—0.00173 µg/µg of microfilter.