A national critical loads framework for atmospheric deposition effects assessment: II. Defining assessment end points,indicators, and functional subregions

The United States Environmental Protection Agency, with support from the US Department of Energy and the National Oceanographic and Atmospheric Administration, has been evaluating the feasibility of an effects-based (critical loads) approach to atmospheric pollutant regulation and abatement. The rationale used to develop three of the six steps in a flexible assessment framework (Strickland and others, 1992) is presented along with a discussion of a variety of implementation approaches and their ramifications. The rationale proposes that it is necessary to provide an explicit statement of the condition of the resource that is considered valuable (assessment end point) because: (1) individual ecosystem components may be more or less sensitive to deposition, (2) it is necessary to select indicators of ecosystem condition that can be objectively measured and that reflect changes in the quality of the assessment end point, and (3) acceptable status (i.e., value of indicator and quality of assessment end point at critical load) must be defined. The rationale also stresses the importance of defining the assessment regions and subregions to improve the analysis and understanding of the indicator response to deposition. Subregional definition can be based on a variety of criteria, including informed judgment or quantitative procedures. It also depends on the geographic scale at which exposure and effects models are accurate and on data availability, resolution, and quality. The research described in this article has been funded by the US Environmental Protection Agency. This document has been prepared at the EPA Environmental Research Laboratory in Corvallis, Oregon, through contract #68-C8-0006 with ManTech Environmental Technology, Inc., and Interagency Agreement #1824-B014-A7 with the US Department of Energy and at Oak Ridge National Laboratory managed by Martin Marietta Energy Systems, Inc., under Contract DE-AC05-84OR21400 with the US Department of Energy. Environmental Sciences Division Publication No. 3903. It has been subjected to the agency’s peer and administrative review and approved for publication. Mention of trade names or commercial products does not constitute endorsement or recommendation for use.     

THROUGHFALL IN PLANTED STANDS OF FOUR SOUTHERN PINE SPECIES IN EAST TEXAS1

Throughfall was measured during 1978–79 beneath the canopies of adjacent stands of four major southern pine species, all on identical soil type and topography in the Stephen F. Austin Experimental Forest. Observations from 44 storms in a randomized network of 15, 5.08 cm PVC gages in a 0.4 ha plot of each species showed that throughfall expressed as percent of storm precipitation, is greatest under longleaf pine and least under loblolly pine; throughfall under shortleaf and slash pine did not differ significantly. Generally, through-fall decreased with storm size and intensity, with distance from the nearest tree stem, and is greater during summer half-year (May–October). Canopy drips, apparently accounting for the greater throughfall for the gage position closer to the stems, were more numerous than reported elsewhere. The 5.08 cm PVC gages proved to be acceptable substitutes for standard nonrecording gages in measuring throughfall. A network of 15 such gages was sufficient to sample throughfall data with 90 percent accuracy in each of the four southern pine plantations.     

From wasteland to wetland: creating a community ecological resource from waste water in regional New South Wales

In areas where rivers have been altered and regulated through dams, the effect on wetland ecosystems can lead to 'wastage' of the land as natural systems are destroyed. In response to the effects of streamflow regulation on a wetland near the city of Albury, on the Murray River, the development of the Wonga Wetlands and associated site rehabilitation addresses two key issues: wasteland and waste water. A Community Advisory Committee has been actively and directly involved in the project, initiated and implemented by the Albury City Council, to restore an area of original wetland into a community ecological resource that utilises 100% of the domestic, commercial and industrial urban 'waste' water from the city's water treatment plant. This project represents a significant direction in the way communities and local governments approach resource recovery. This paper analyses the Wonga Wetlands project from the perspective of sustainable management of waste in terms of water resources and presents it as a model for community-based environmental application and long-term resource sustainability.     

Targeted sampling protocol as prelude to bacterial source tracking with Enterococcus faecalis

Recent studies suggest that host origin databases for bacterial source tracking (BST) must contain a large number of isolates because bacterial subspecies change with geography and time. A new targeted sampling protocol was developed as a prelude to BST to minimize these changes. The research was conducted on the Sapelo River, a tidal river on the Georgia coast. A general sampling of the river showed fecal enterococcal numbers ranging from <10 (below the limit of detection) to 990 colony-forming units (CFU) per 100 mL. Locations with high enterococcal numbers were combined with local knowledge to determine targeted sampling sites. Fecal enterococcal numbers around one site ranged from <10 to 24,000 CFU per 100 mL. Bacterial source tracking was conducted to determine if a wastewater treatment facility at the site was responsible for this contamination. The fecal indicator bacterium was Enterococcus faecalis. Ribotyping, automated with a RiboPrinter (DuPont Qualicon, Wilmington, DE), was the BST method. Thirty-seven ribotypes were observed among 83 Ent. faecalis isolates obtained from the Sapelo River and the wastewater lagoon. Sixteen ribotypes were associated with either the river or the lagoon, and only five ribotypes (14%) were shared. Nevertheless, these five ribotypes represented 39 of the 83 Ent. faecalis isolates, almost a majority (47%). These results suggest that the fecal contamination in the river came from the wastewater treatment facility. As a prelude to BST, targeted sampling minimized subspecies changes with geography and time, and eliminated the need for a permanent host origin database by restricting BST to a small geographic area and requiring sampling to be completed in one day.     

Levels and trends of polybrominated diphenylethers and other brominated flame retardants in wildlife

In this paper, we review the available data for polybrominated diphenylethers (PBDEs) and other flame retardants in wildlife, with the exception of fishes from Europe and North America which are covered in more detail elsewhere. More data are available for PBDEs than for other compounds, and these show that some of these compounds have become widely distributed in the environment, being found in samples from Europe, Australia, Azerbaijan, North America and the Arctic. Most available data relate to birds and their eggs and marine mammals, but the results of two food web studies are also included. The detection of PBDEs in pelagic marine mammals which feed in deep offshore waters, including baleen whales, indicate that these compounds have found their way into deep-water, oceanic food webs as well as the coastal/shallow sea examples described in detail. In the North Sea study, the most marked increase in lipid-normalised concentrations of six BDE congeners occurred during transfer from predatory fish to marine mammals. In the St. Lawrence Estuary study, marked differences in the ratios observed between species suggested that some fish species may be able to metabolise BDE99.A number of time trend studies have also been conducted, notably in guillemot eggs from Sweden (1969-2000), beluga whales from the Canadian Arctic (1982-1997 and 1989-2001) and from the St. Lawrence Estuary (1988-1999), and ringed seals from the Canadian Arctic (1981-2000). In the temperate latitudes, from these and other studies (e.g. in dated sediment cores), PBDE concentrations began to rise earlier than in those from high latitudes, in line with data for production and use. These trends have now slowed in many cases. Declines could be expected in Europe for many congeners following the cessation of manufacture and use of the penta-mix formulation in the EU, though these are not yet apparent in environmental samples. In Arctic biota, however, the rapidly rising concentrations seen currently in Canada could be expected to continue for some time, reflecting continued production and use of the penta-mix formulation in North America (>95% of the world total) and the impact of long-range atmospheric transport.     

The Impact of Local versus National Framing on Willingness to Reduce Greenhouse Gas Emissions: a case study from central Pennsylvania

This paper explores the impact of the frame in which people interpret global warming. In 1999, 637 respondents completed a mail survey in five counties in central Pennsylvania. Half of the sample received questionnaires that framed global warming in terms of the local impacts of mitigation policies, whereas the other half received questionnaires that framed global warming in terms of the national impacts of mitigation policies. The results show a statistically significant but small difference between the local and national frames in the respondents' willingness to support government policies, as well as to take voluntary actions to mitigate climate change.     

Preliminary Studies on the Population Genetics of the Central Stoneroller (Campostoma anomalum) from the Great Miami River Basin, Ohio

Molecular approaches are particularly useful for measuring genetic diversity and were applied to samples of central stonerollers obtained from sites along tributaries to the Great Miami River in Ohio. We used Random Amplified Polymorphic DNA (RAPD) analysis to assess the level of genetic diversity within and among these populations. RAPD analysis generates genetic profiles that were used to develop indices of genetic similarity. The RAPD method provides a cost effective means of generating an arbitrary sample of anonymous loci across the genome and generate a virtually unlimited set of loci for use in genetic analysis in the absence of specific sequence information. These attributes make RAPDs well suited for use in evaluating the diversity and assessing the potential vulnerability to exposure of populations across multiple spatial scales. The results demonstrate that a significant amount of structuring exists among populations analyzed to date and that a trend exists towards genetic diversity being an inverse function of site distance from the main stem as well as a being directly related to stream order. This indicates that populations farthest from main conduits or in lower order streams, and thereby most isolated, may be the most vulnerable populations to stressor exposure. It is hoped that information pertaining to genetic diversity, when integrated with other metrics of resource condition, will aid in making scientifically grounded decisions on resource management that enhance the probability of population survival and preserve natural evolutionary processes.