Multiscale Analysis of Restoration Priorities for Marine Shoreline Planning

Planners are being called on to prioritize marine shorelines for conservation status and restoration action. This study documents an approach to determining the management strategy most likely to succeed based on current conditions at local and landscape scales. The conceptual framework based in restoration ecology pairs appropriate restoration strategies with sites based on the likelihood of producing long-term resilience given the condition of ecosystem structures and processes at three scales: the shorezone unit (site), the drift cell reach (nearshore marine landscape), and the watershed (terrestrial landscape). The analysis is structured by a conceptual ecosystem model that identifies anthropogenic impacts on targeted ecosystem functions. A scoring system, weighted by geomorphic class, is applied to available spatial data for indicators of stress and function using geographic information systems. This planning tool augments other approaches to prioritizing restoration, including historical conditions and change analysis and ecosystem valuation.     

Perfluorinated compounds in the Antarctic region: Ocean circulation provides prolonged protection from distant sources

In order to investigate the extent to which Perfluorinated Contaminants (PFCs) have permeated the Southern Ocean food web to date, a range of Antarctic, sub-Antarctic and Antarctic-migratory biota were analysed for key ionic PFCs.Based upon the geographical distribution pattern and ecology of biota with detectable vs. non-detectable PFC burdens, an evaluation of the potential contributory roles of alternative system input pathways is made. Our analytical findings, together with previous reports, reveal only the occasional occurrence of PFCs in migratory biota and vertebrate predators with foraging ranges extending into or north of the Antarctic Circumpolar Current (ACC).Geographical contamination patterns observed correspond most strongly with those expected from delivery via hydrospheric transport as governed by the unique oceanographic features of the Southern Ocean. We suggest that hydrospheric transport will form a slow, but primary, input pathway of PFCs to the Antarctic region.     

CCA-treated wood disposed in landfills and life-cycle trade-offs with waste-to-energy and MSW landfill disposal

Chromated copper arsenate (CCA)-treated wood is a preservative treated wood construction product that grew in use in the 1970s for both residential and industrial applications. Although some countries have banned the use of the product for some applications, others have not, and the product continues to enter the waste stream from construction, demolition and remodeling projects. CCA-treated wood as a solid waste is managed in various ways throughout the world. In the US, CCA-treated wood is disposed primarily within landfills; however some of the wood is combusted in waste-to-energy (WTE) facilities. In other countries, the predominant disposal option for wood, sometimes including CCA-treated wood, is combustion for the production of energy. This paper presents an estimate of the quantity of CCA-treated wood entering the disposal stream in the US, as well as an examination of the trade-offs between landfilling and WTE combustion of CCA-treated wood through a life-cycle assessment and decision support tool (MSW DST). Based upon production statistics, the estimated life span and the phaseout of CCA-treated wood, recent disposal projections estimate the peak US disposal rate to occur in 2008, at 9.7 million m(3). CCA-treated wood, when disposed with construction and demolition (C&D) debris and municipal solid waste (MSW), has been found to increase arsenic and chromium concentrations in leachate. For this reason, and because MSW landfills are lined, MSW landfills have been recommended as a preferred disposal option over unlined C&D debris landfills. Between landfilling and WTE for the same mass of CCA-treated wood, WTE is more expensive (nearly twice the cost), but when operated in accordance with US Environmental Protection Agency (US EPA) regulations, it produces energy and does not emit fossil carbon emissions. If the wood is managed via WTE, less landfill area is required, which could be an influential trade-off in some countries. Although metals are concentrated in the ash in the WTE scenario, the MSW landfill scenario releases a greater amount of arsenic from leachate in a more dilute form. The WTE scenario releases more chromium from the ash on an annual basis. The WTE facility and subsequent ash disposal greatly concentrates the chromium, often oxidizing it to the more toxic and mobile Cr(VI) form. Elevated arsenic and chromium concentrations in the ash leachate may increase leachate management costs.     

Application of the US decision support tool for materials and waste management

The US Environmental Protection Agency (US EPA) launched the Resource Conservation Challenge (RCC) in 2002 to help reduce waste and move towards more sustainable resource consumption. The objective of the RCC is to help communities, industries, and the public think in terms of materials management rather than waste disposal. Reducing cost, finding more efficient and effective strategies to manage municipal waste, and thinking in terms of materials management requires a holistic approach that considers life-cycle environmental tradeoffs. The US EPA's National Risk Management Research Laboratory has led the development of a municipal solid waste decision support tool (MSW-DST). The computer software can be used to calculate life-cycle environmental tradeoffs and full costs of different waste management or materials recovery programs. The environmental methodology is based on the use of life-cycle assessment and the cost methodology is based on the use of full-cost accounting. Life-cycle inventory (LCI) environmental impacts and costs are calculated from the point of collection, handling, transport, treatment, and disposal. For any materials that are recovered for recycling, offsets are calculated to reflect potential emissions savings from use of virgin materials. The use of the MSW-DST provides a standardized format and consistent basis to compare alternatives. This paper provides an illustration of how the MSW-DST can be used by evaluating ten management strategies for a hypothetical medium-sized community to compare the life-cycle environmental and cost tradeoffs. The LCI results from the MSW-DST are then used as inputs into another US EPA tool, the Tool for the reduction and assessment of chemical and other environmental impacts, to convert the LCI results into impact indicators. The goal of this paper is to demonstrate how the MSW-DST can be used to identify and balance multiple criteria (costs and environmental impacts) when evaluating options for materials and waste management. This type of approach is needed in identifying strategies that lead to reduced waste and more sustainable resource consumption. This helps to meet the goals established in the US EPA's Resource Conservation Challenge.     

Declining metal levels at Foundry Cove (Hudson River, New York): response to localized dredging of contaminated sediments

This study examines the effectiveness of remediating a well-recognized case of heavy metal pollution at Foundry Cove (FC), Hudson River, New York. This tidal freshwater marsh was polluted with battery-factory wastes (1953-1979) and dredged in 1994-1995. Eight years after remediation, dissolved and particulate metals (Cd, Co, Cu, Pb, Ni, and Ag) were found to be lower than levels in the lower Hudson near New York City. Levels of metals (Co, Ni, Cd) on suspended particles were comparatively high. Concentrations of surface sediment Cd throughout the marsh system remain high, but have decreased both in the dredged and undredged areas: Cd was 2.4-230mg/kg dw of sediment in 2005 vs. 109-1500mg/kg in the same area in 1983. The rate of tidal export of Cd from FC has decreased by >300-fold, suggesting that dredging successfully stemmed a major source of Cd to the Hudson River.     

Ethnobotanical skills and clearance of tropical rain forest for agriculture: a case study in the lowlands of Bolivia

Indigenous peoples are often considered potential allies in the conservation of biological diversity. Here we assess whether ethnobotanical skills of indigenous people contribute to a reduction in the clearance of tropical rain forest. We measured ethnobotanical skills of male household heads and area of rain forest cleared for agriculture among 128 households of Tsimane', a native Amazonian group in Bolivia. We used multivariate regressions to estimate the relation between ethnobotanical skills and area of rain forest cleared while controlling for schooling, health status, number of plots cleared, adults in household, and village of residency. We found that when the ethnobotanical skills of the male household head were doubled, the amount of tropical rain forest cleared per household was reduced by 25%. The association was stronger when the area of old-growth forest cleared was used as the dependent variable than when the area cleared from fallow forest was used as the dependent variable. People who use the forest for subsistence might place a higher value on standing forest than people who do not use it, and thus they may be more reluctant to cut down the forest.     

The influence of suburban land use on habitat and biotic integrity of coastal Rhode Island streams

Watershed land use in suburban areas can affect stream biota through degradation of instream habitat, water quality, and riparian vegetation. By monitoring stream biotic communities in various geographic regions, we can better understand and conserve our watershed ecosystems. The objective of this study was to examine the relationship between watershed land use and the integrity of benthic invertebrate communities in eight streams that were assessed over a 3-year period (2001-2003). Sites were selected from coastal Rhode Island watersheds along a residential land-use gradient (4-59%). Using the rapid bioassessment protocol, we collected biological, physicochemical, habitat, and nutrient data from wadeable stream reaches and compared metrics of structure and integrity. Principal component analyses showed significant negative correlation of indicators for stream physicochemical, habitat, and instream biodiversity with increasing residential land use (RLU) in the watershed. The physicochemical variables that were most responsive to percent RLU were conductivity, instream habitat, nitrate, and dissolved inorganic nitrogen (DIN). The positive correlation of DIN with percent RLU indicated an anthropogenic source of pollution affecting the streams. The biotic composition of the streams shifted from sensitive to insensitive taxa as percent RLU increased; the most responsive biological variables were percent Ephemeroptera, percent Scrapers, percent Insects, and the Hilsenhoff biotic index. These data show the importance of land management and conservation at the watershed scale to sustaining the biotic integrity of coastal stream ecosystems.     

Predicting coral bleaching in response to environmental stressors using 8 years of global-scale data

Coral reefs have experienced extensive mortality over the past few decades as a result of temperature-induced mass bleaching events. There is an increasing realization that other environmental factors, including water mixing, solar radiation, water depth, and water clarity, interact with temperature to either exacerbate bleaching or protect coral from mass bleaching. The relative contribution of these factors to variability in mass bleaching at a global scale has not been quantified, but can provide insights when making large-scale predictions of mass bleaching events. Using data from 708 bleaching surveys across the globe, a framework was developed to predict the probability of moderate or severe bleaching as a function of key environmental variables derived from global-scale remote-sensing data. The ability of models to explain spatial and temporal variability in mass bleaching events was quantified. Results indicated approximately 20% improved accuracy of predictions of bleaching when solar radiation and water mixing, in addition to elevated temperature, were incorporated into models, but predictive accuracy was variable among regions. Results provide insights into the effects of environmental parameters on bleaching at a global scale.     

Liver lesions in demersal fishes near a large ocean outfall on the San Pedro Shelf, California

The prevalence of toxicopathic liver lesions in demersal fish on the San Pedro Shelf, California was determined for a 15-year period (1988–2003). Fish livers were sampled at fixed locations as part of the Orange County Sanitation Districts (OCSD) ocean monitoring program. Histopathological examination of selected fish liver tissues was studied to determine whether the wastewater discharge had affected fish health. The prevalence of toxicopathic lesion classes neoplasms (NEO), preneoplastic foci of cellular alteration (FCA), and hydropic vacuolation (HYDVAC) varied among species and locations. For all species sampled, severe lesions occurred in 6.2% of the fish examined (n = 7,694). HYDVAC (4.1%) was the most common toxicopathic lesion type followed by FCA (1.4%) and NEO (0.7%). HYDVAC occurred only in white croaker (Genyonemus lineatus), accounting for 84.8% of the toxicopathic lesions for this species. Prevalence of HYDVAC, NEO, and FCA in white croaker was 15.2, 2.0, and 0.7%, respectively. The prevalence of HYDVAC and NEO in white croaker increased with age and size but there was no sexual difference. A linear regression model was used for hypothesis testing to account for significant differences in fish size (and age for croakers) at the different sampling locations. This analysis showed that for HYDVAC there was no spatial or location effect for lesion rate or size/age of onset. For NEO, the model predicted that white croaker near the wastewater outfall may acquire these lesions at a smaller size/younger age, and at a higher rate, than at other sites. However, this result may be biased due to the unequal size frequency distributions and the low prevalence of NEO in white croaker at the different sampling sites. Bigmouth sole (Hippoglossina stomata) had a prevalence of FCA and NEO of 1.3 and 0.35%, respectively, but the prevalence and distribution of lesions was too few for statistical testing. There was no sexual difference for lesion prevalence in hornyhead turbot (Pleuronichthys verticalis) and the prevalence of FCA and NEO was 3.4 and 0.37%, respectively. FCA prevalence increased with size in hornyhead turbot and there were no significant spatial differences for lesion rates and fish size at lesion onset. Overall, consistent spatial differences for lesion prevalence were not demonstrated and highlight the analytical difficulties of detecting a possible point source impact when the effect is rare, correlated with the size/age structure of the population, and may be caused by exposure to unknown multiple sources. Thus, the usefulness of liver histopathology as a point-source monitoring tool is best applied to where the spatial scale of impact generally exceeds the home range of the target species.