A toxicological assessment of two aquatic ecosystems in the greater Houston area. Part I: Risk assessment of Buffalo Bayou. Part II: Water quality assessment of the mariculture ponds of Sea Center Texas.

摘要

Aquatic toxicology is explored in this study by an in depth assessment of two distinctly different aquatic Ecosystems. Buffalo Bayou, a tributary of Houston that develops into the Houston Ship Channel, is under increasing Anthropogenic stress—industrial, commercial, navigational, and domestic. Part I of this study characterizes the organic pollutants that have accumulated over the years in the sediment compartment of the Buffalo Bayou ecosystem. Part II assesses the water chemistry and profiles the physicochemical character of the mariculture ponds at Sea Center Texas in an attempt to improve the survival and growth of the red drum fry while comparing attributes of two aeration devices—The industry standard Paddlewheel and the newly patented microbubble technology the Aerob-a-jet™.; Contamination of bottom sediments by toxic chlorinated pesticides and polynuclear aromatic hydrocarbons was observed in Buffalo Bayou. The chlorinated pesticides found include heptachlor epoxide, gama-chlordane, alpha-chlordane, endosulfan II, and endrin aldehyde. The polynuclear aromatic hydrocarbons found in analyzed sediment samples were phenanthrene, fluoranthene, pyrene, benz[a]anthracene, benzo[k]fluoranthene, and benzo[a]pyrene. Concentrations of these contaminants were significantly higher east of Downtown Houston near the turning basin of the Houston Ship Channel. The risk assessment of PAH toxicity was determined to be an imminent ecological threat to the Buffalo Bayou Aquatic Ecosystem.; In the mariculture study at Sea Center Texas, it was concluded that the most critical stage in the process of raising red drum fingerlings is the transition period between the incubator stage and their stocking into the rearing pond. It is vital to the survival of the fry that the dissolved oxygen levels of newly stocked ponds are maintained between 6–8 mg/L, and the zooplankton colony is maintained at a count 2000–3000 organisms/L for the first 5 days of the fry's life in the rearing pond. Furthermore, it was concluded that the Aerob-a-jet™ was more appropriately designed for aeration of the water column during the initial days, the most critical stage, of stocking red drum larva into mariculture rearing ponds.