Academic Articles

IN TO THE DEEPThe pioneering underwater archaeologist ignored academics who said he was wasting his time and professional divers who assumed he would not make it out of the water alive.Much of human history is hidden beneath the waves: Some 3,000,000 shipwrecks may rest on the world's seabeds. But archaeologists had to rely on professional ... Read More

Abstract: Fish can become stranded when water levels decrease, often rapidly, as a result of anthropogenic (e.g., canal drawdown, hydropeaking, vessel wakes) and natural (e.g., floods, drought, winter ice dynamics) events. We summarize existing research on stranding of fish in freshwater, discuss the sources, consequences, and mitigation options for stranding, and report current knowledge gaps. Our literature review revealed that ∼65.5% of relevant peer-reviewed articles were found to focus on stranding associated with hydropower operations and irrigation projects. In fact, anthropogenic sources of fish stranding represented 81.8% of available literature compared to only 19.9% attributed to natural fish stranding events. While fish mortality as a result of stranding is well documented, our analysis revealed that little is known about the sublethal and long-term consequences of stranding on growth and population dynamics. Furthermore, the contribution of stranding to annual mortality rates is poorly understood as are the potential ecosystem-scale impacts. Mitigation strategies available to deal with stranding include fish salvage, ramping rate limitations, and physical habitat works (e.g., to contour substrate to minimize stranding). However, a greater knowledge of the factors that cause fish stranding would promote the development and refinement of mitigation strategies that are economically and ecologically sustainable. [Copyright &y& Elsevier]

Abstract: In-situ filtration of phosphorus (P) and particulate matter (PM) transported in runoff is increasingly implemented for urban source areas. While monitoring of filter response is commonly based on an event mean of total phosphorus (TP), this study examines the fate of specific P fractions through intra- and inter-event phenomena. This continuous filter monitoring program includes 15 wet weather loadings and the dry weather periods between these events. Aqueous P adsorption and PM-bound P (suspended, settleable and sediment) filtration phenomena are examined for runoff events from a landscaped carpark with biogenic loads in Gainesville (GNV), FL. Filter response is compared to a similar aluminum oxide Al-Ox modified media filter subject to anthropogenic loads from an urban paved source area in Baton Rouge (BTR), LA. Results for the GNV filter indicate that while intra-event settleable, sediment and dissolved P fractions are controlled by the filter, the suspended P fraction remained relatively mobile compared to the other P fractions. P adsorption is primarily influenced by intra-event flow rates, contact times, runoff volume, pH and by the inter-event chemistry of runoff stored in the filter. P effluent partitioning is dominated by the suspended PM as a consequence of effective adsorption by the filter. Inter-event phenomena generate decreasing redox with commensurate increases in alkalinity, conductivity as well as dissolved P as a consequence of re-partitioning. Dissolved P fate suggests that filters should be designed and managed to remain aerobic between wet weather events. For effective separation of suspended P and PM fractions by passive filters with low driving head, sustainability of performance, including head loss {<3 kPa}, requires upstream volumetric attenuation. [Copyright &y& Elsevier]

Abstract: Increasing concerns regarding water quality in the Great Lakes region are mainly due to changes in urban and agricultural landscapes. Both point and non-point sources contribute pollution to Great Lakes surface waters. Best management practices (BMPs) are a common tool used to reduce both point and non-point source pollution and improve water quality. Meanwhile, identification of critical source areas of pollution and placement of BMPs plays an important role in pollution reduction. The goal of this study is to evaluate the performance of different targeting methods in 1) identifying priority areas (high, medium, and low) based on various factors such as pollutant concentration, load, and yield, 2) comparing pollutant (sediment, total nitrogen-TN, and total phosphorus-TP) reduction in priority areas defined by all targeting methods, 3) determine the BMP relative sensitivity index among all targeting methods. Ten BMPs were implemented in the Saginaw River Watershed using the Soil and Water Assessment Tool (SWAT) model following identification of priority areas. Each targeting method selected distinct high priority areas based on the methodology of implementation. The concentration based targeting method was most effective at reduction of TN and TP, likely because it selected the greatest area of high priority for BMP implementation. The subbasin load targeting method was most effective at reducing sediment because it tended to select large, highly agricultural subbasins for BMP implementation. When implementing BMPs, native grass and terraces were generally the most effective, while conservation tillage and residue management had limited effectiveness. The BMP relative sensitivity index revealed that most combinations of targeting methods and priority areas resulted in a proportional decrease in pollutant load from the subbasin level and watershed outlet. However, the concentration and yield methods were more effective at subbasin reduction, while the stream load method was more effective at reducing pollutants at the watershed outlet. The results of this study indicate that emphasis should be placed on selection of the proper targeting method and BMP to meet the needs and goals of a BMP implementation project because different targeting methods produce varying results. [Copyright &y& Elsevier]

Abstract: Nepal’s conservation areas and community forests are generally considered as successful community-based conservation models. The paper’s goal is to investigate the factors that consistently predict the level of trust local governing bodies have on administering agencies in these models. Both quantitative and qualitative data were collected through field research in the Annapurna Conservation Area (ACA) in the summer of 2007 and adjacent community forests in the fall of 2008. The Conservation Area Management Committee (CAMC) and the Community Forest User Committee (CFUC) are the functional decision-making entities at the local level in ACA and the community forests, respectively. I conducted one-on-one semi-structured interviews with 66 executive members of 10 CAMCs and 67 members of 9 CFUCs. In multiple regression models relating the levels of trust committee members had for administering staff and agencies to a set of 7 theoretically informed covariates, 4 were statistically significant in ACA and 3 in the community forests. In ACA, committee members’ overall assessment of the agency’s performance, perceptions regarding the agency staff’s understanding of local culture, perceptions regarding the equitable distribution of conservation benefits, and perceptions regarding the dependence upon the agency were statistically significant variables that influenced trust. In the community forests, committee members’ overall assessment of the agency’s performance, perceptions regarding the agency staff’s understanding of local culture, and rational assessments of the benefits and costs associated with being a member explained significant variations in the levels of trust. The most consistent predictors of agency trust in both the models were committee members’ overall assessment of the agency’s performance, and perceptions regarding the agency staff’s understanding of local culture. These findings suggest that natural resource management agencies can devise strategies for building trust with local governing bodies by a combination of above average performance and deeper understanding of local culture. [Copyright &y& Elsevier]