Assessing the Effects of Non-Point Source Pollution on American Samoa’s Coral Reef Communities

Surveys were completed on Tutuila Island, American Samoa, to characterize reef development and assess the impacts of non-point source pollution on adjacent coral reefs at six sites. Multivariate analyses of benthic and coral community data found similar modern reef development at three locations; Aoa, Alofau, and Leone. These sites are situated in isolated bays with gentle sloping foundations. Aoa reefs had the highest estimates of crustose coralline algae cover and coral species richness, while Leone and Alofau showed high abundances of macroalgae and Porites corals. Aoa has the largest reef flat between watershed discharge and the reef slope, and the lowest human population density. Masefau and Fagaalu have a different geomorphology consisting of cemented staghorn coral fragments and steep slopes, however, benthic and coral communities were not similar. Benthic data suggest Fagaalu is heavily impacted compared with all other sites. Reef communities were assessed as bio-criteria indicators for waterbody health, using the EPA aquatic life use support designations of (1) fully supportive, (2) partially supportive, and (3) non-supportive for aquatic life. All sites resulted in a partially supportive ranking except Fagaalu, which was non-supportive. The results of this rapid assessment based upon relative benthic community measures are less desirable than long-term dataset analyses from monitoring programs, however it fills an important role for regulatory agencies required to report annual waterbody assessments. Future monitoring sites should be established to increase the number of replicates within each geological and physical setting to allow for meaningful comparisons along a gradient of hypothesized pollution levels.     

Elevated atmospheric ozone increases concentration of insecticidal Bacillus thuringiensis (Bt) Cry1Ac protein in Bt Brassica napus and reduces feeding of a Bt target herbivore on the non-transgenic parent

Sustained cultivation of Bacillus thuringiensis (Bt) transgenic crops requires stable transgene expression under variable abiotic conditions. We studied the interactions of Bt toxin production and chronic ozone exposure in Bt cry1Ac-transgenic oilseed rape and found that the insect resistance trait is robust under ozone elevations. Bt Cry1Ac concentrations were higher in the leaves of Bt oilseed rape grown under elevated ozone compared to control treatment, measured either per leaf fresh weight or per total soluble protein of leaves. The mean relative growth rate of a Bt target herbivore, Plutella xylostella L. larvae was negative on Bt plants in all ozone treatments. On the non-transgenic plants, larval feeding damage was reduced under elevated ozone. Our results indicate the need for monitoring fluctuations in Bt toxin concentrations to reveal the potential of ozone exposure for altering dosing of Bt proteins to target and non-target herbivores in field environments experiencing increasing ozone pollution.     

Detection and quantification of chlordecone in contaminated soils from the French West Indies by GC-MS using the 13C10-chlordecone stable isotope as a tracer

Chlordecone is an organochlorine insecticide that has been widely used to control banana weevil in the French West Indies. As a result of this intense use, up to 20,000 ha are contaminated by this insecticide in the French West Indies, and this causes environmental damage and health problems. A scenario of exposure was drawn by French authorities, based on land usage records. Many efforts have been made to monitor the occurrence of chlordecone and its main metabolites using different analytical methods, including GC, GC/MS, LC/MS, and NIRS. Although these different methods allow for the detection and quantification of chlordecone from soils, none of them estimate the bottleneck caused by extraction of this organochlorine from soils with high adsorption ability. In this study, we used ¹³C₁₀-chlordecone as a tracer to estimate chlordecone extraction yield and to quantify chlordecone in soil extracts based on the ¹³C/¹²C isotope dilution. We report the optimization of ¹³C₁₀-chlordecone extraction from an Andosol. The method was found to be linear from 0.118 to 43 mg kg^?1 in the Andosol, with an instrumental detection limit estimated at 8.84 μg kg^?1. This method showed that chlordecone ranged from 35.4 down to 0.18 mg kg^?1 in Andosol, Nitisol, Ferralsol, and Fluvisol soil types. Traces of the metabolite β-monohydrochlordecone were detected in the Andosol, Nitisol, and Ferralsol soil samples. This last result indicates that this method could be useful to monitor the fate of chlordecone in soils of the French West Indies.     

Econometric analysis of the determinants of adoption of alley farming by farmers in the forest zone of southwest Cameroon

Slash-and-burn agriculture continues to expand in many parts of the forest zone of Cameroon. One alternative land use to slash-and-burn system is alley farming. This paper quantifies, using an econometric model, the factors determining farmers’ adoption and use of alley farming variants in southwest of Cameroon, based on a survey of 156 farmers in 11 villages in the region.The analysis showed that male farmers are more likely to adopt than women. Adoption is higher for farmers with contacts with extension agencies working on agroforestry technologies. Adoption is higher for farmers belonging to farmers’ groups. Adoption is lower for farmers in areas with very high population pressure, as farmers in such areas may have greater labor productivity from use of less labor intensive natural resource management technologies like chemical fertilizers. Adoption is higher for farmers in areas facing fuel wood scarcity. Farmers have made adaptations to the conventional alley farming technology recommended by researchers, the most significant adaptation being the introduction of fallow periods into the system. Farmers use alley farming as a land use option, not as a replacement for the slash-and-burn system, since land supply is still relatively elastic. Achieving increased impact with alley farming variants requires effective targeting. Results showed that econometric modeling using farmer and village characteristics, socioeconomic and institutional variables can lead to more effective targeting to farmers and locations where higher adoption rates may occur.     

Quality Assurance for the SITE Program Demonstrations

The U.S. Environmental Protection Agency has implemented a rigorous quality assurance (QA) program to ensure that the performance data generated during their Superfund Innovative Technology Evaluation (SITE) Demonstration projects are of known and adequate quality to support decisions to use such technologies for hazardous waste site characterizations or remediations. A general overview of the ways in which this QA program has been conducted and of the results it has produced is presented.     

Integrating local and scientific knowledge for environmental management

This paper evaluates the processes and mechanisms available for integrating different types of knowledge for environmental management. Following a review of the challenges associated with knowledge integration, we present a series of questions for identifying, engaging, evaluating and applying different knowledges during project design and delivery. These questions are used as a basis to compare three environmental management projects that aimed to integrate knowledge from different sources in the United Kingdom, Solomon Islands and Australia. Comparative results indicate that integrating different types of knowledge is inherently complex – classification of knowledge is arbitrary and knowledge integration perspectives are qualitatively very different. We argue that there is no single optimum approach for integrating local and scientific knowledge and encourage a shift in science from the development of knowledge integration products to the development of problem-focussed, knowledge integration processes. These processes need to be systematic, reflexive and cyclic so that multiple views and multiple methods are considered in relation to an environmental management problem. The results have implications for the way in which researchers and environmental managers undertake and evaluate knowledge integration projects.