To address public concern over potential ecological effects on commercially and ecologically important species following use of dispersants during oil spill response efforts, toxicity data was generated for three estuarine species indigenous to the Gulf of Mexico including juvenile Gulf killifish Fundulus grandis, white shrimp Litopenaeus setiferus, and Eastern oyster Crassostrea virginica. The acute toxicity of the dispersant Exxon Corexit 9500, South Louisiana crude oil (SLC), Alaskan north slope crude oil (ANSC) and dispersed oils (SLC+9500 and ANSC+9500) to the species was determined for both nominal concentrations (NC) and hydrocarbon concentrations (HC). Two 24-h field toxicity trials were conducted with the same species in a Louisiana coastal marsh, using ANSC and ANSC+9500, dosed at a NC of 30 ppm. White shrimp were more sensitive to dispersant, crude oils, and dispersed oils than killifish and oysters. The 96-h NC LC50 for crude oil and dispersed oil ranged from 370 to 4,500 ppm for killifish (HC 7.6 to 18.7 ppm) and 60 to 180 ppm for shrimp (HC 5 to 7.5 ppm). Mortality in oysters was not positively correlated with increasing levels of crude oils, or dispersed oils. Dispersed oils were more toxic than crude oils based on nominal concentrations, but no difference in toxicity of crude oils and dispersed oils was observed based on HC concentrations. No synergistic toxicity action was found between SLC or ANSC and dispersant Corexit 9500 based on HC concentrations. Survival was relatively high for all three species during the two 24-h field trials, generally exceeding 83% in crude oil and dispersed oil enclosures. Mortality of white shrimp was slightly higher than observed in killifish and oysters. The HC concentration in ANSC+9500 and ANSC enclosures ranged from 14 to 24 ppm and 10 to 11 ppm, respectively, at 0 h and declined to near 0 ppm in 3 hours. The rapid decrease was attributed to dilution from vertical mixing and tidal action. Both laboratory finding and field studies indicate that short-term exposure to nominal concentrations of ANSC or ANSC+9500 of 30 ppm or less are not likely to have an acute toxic effect on these species.

Chromated copper arsenate (CCA) treated wood is an economical, durable and aesthetically pleasing residential material used for many exterior application such as decks, fences, playground equipment, utility poles, and others. It has been most widely used in North America since the 1970s. A large volume of CCA-treated wood is currently coming out of service. Traditional landfilling or incineration is environmentally unacceptable. Recycling CCA-treated wood into composite products is one alternative to ease the disposal problem. It also has the potential to relieve harvesting pressure from the nation's forestlands. After recycling, the remaining CCA content in the wood can still have preserving capability against decay. In this study, the effects of different ratios of recycled CCA-treated wood and untreated virgin wood on flakeboard properties were compared. The mechanical, physical, decay resistance, elemental concentrations, and leaching characteristics of flakeboards manufactured from five different ratios of recycled CCA-treated wood and untreated virgin southern pine wood were investigated. The ratios were 100:0, 75:25, 50:50, 25:75, and 0:100. The CCA retention levels of out-of-service CCA-treated posts (experimental raw material) as well as the flakeboard fabricated from the different ratios of recycled CCA-treated wood and untreated virgin wood were also tested. The median ratio with 50% of CCA-treated wood and un-treated wood was found to be the optimum combination. In this case, residual CCA level was sufficient enough to prevent substantial weight losses for the decay tests but low enough so that panel mechanical and physical properties were not substantially adversely affected.

Previous studies have shown that pen-raised deer may be already predisposed to malnutrition at a higher rate then their native counterparts because they are normally raised on a pelleted ration and may not forage efficiently once released into wild habitats. Therefore, twenty pen-raised white-tailed deer that were offspring of deer obtained from Missouri (Odocoileus virginianus) were released onto a marsh pump-off habitat in southeast Louisiana (Da Bunch) to compare their diets to the diets of the native, wild, white-tail deer population already established in the area over four consecutive seasons to test this hypothesis. The microhistological analysis technique was used to estimate the botanical compositions of fecal pellets collected from both populations of deer located in the same range, over four consecutive seasons (Spring, Summer, Fall, and Winter) to account for seasonal variability. Native, wild and pen-raised deer diets averaged 78.2% similar during the year of the study, and were significantly associated to one another during each of the four seasons (P < 0.00001), indicating that all deer foraged on similar plant species in similar proportions. Differences were found in species frequencies per fecal sample, but for only five of the fifty-one species utilized significant differences were found (P < 0.001) between populations. Those species were Diodia virginiana in the spring, Aeschynomene americana, Ambrosia spp. during fall, and Berchemia scandens and Celtis laevigata in the winter. Both deer populations were predominantly grazers, with forbs constituting for a yearly average of 41.20% the deer diets. This study agrees with previous studies that concluded that translocated deer released into a new environment will adapt to the area and forage just as efficiently as the pre-existing deer population in the area assuming carrying capacity is not compromised.