Hallett J. Harris

Uptake of planar polychlorinated biphenyls and 2,3,7,8-substituted polychlorinated dibenzofurans and dibenzo-p-dioxins by birds nesting in the lower fox river and Green Bay, Wisconsin, USA

The uptake of persistent polychlorinated hydrocarbons (PCHs) by four avian species was investigated at upper trophic levels of two aquatic food chains of the lower Fox River and Green Bay, Wisconsin. Accumulation of total and specific planar polychlorinated biphenyls (PCBs), polychlorinated dibenzofurans (PCDFs), polychlorinated dibenzo-p-dioxin (PCDDs), and H411E rat hepatoma cell bioassay-derived 2,37,8-tetrachlorodibenzop-dioxin equivalents (TCDD-EQ) was evaluated in Forsters tern (Sterna forsteri) and common tern (Sterna hirundo) chicks, and in tree swallow (Tachycineta bicolor) and red-winged blackbird (Agelaius phoeniceus) nestlings from colonies nesting in several locations within the watershed. Concentrations of the PCHs were greatest in eggs and chicks of the two tern species, less in the tree swallows and least in the red-winged blackbirds. Young of all four species accumulated total PCBs, PCB congeners 77, 105, 126, and 169, and TCDD-EQ. The young birds also accumulated small concentrations of several 2,3,7,8-sbustituted PCDF and PCDD congeners. Uptake rates for certain of the PCHs for the Forsters tern chicks were: 15 μg/day for total PCBs, 70, 200, 6.5, and 0.14 ng/day for PCB congeners 77, 105, 126, and 169, respectively, and 270 μg/day for TCDD-EQ. Principal components analysis revealed that the patterns of PCH concentrations in the samples were influenced by species of bird, their age (or length of exposure) and nesting location. Collectively, our findings demonstrate that exposure of avian species to contaminants derived from aquatic food chains can be characterized and quantified for the purposes of ecological risk assessment.

Measures of reproductive success and polychlorinated biphenyl residues in eggs and chicks of Forster's terns on Green Bay, Lake Michigan, Wisconsin—1988

AbstractData on reproductive success of Forsters tern (Sterna forsteri) from Green Bay, Lake Michigan in 1983 are compared with data collected in 1988. In 1988 measures of reproductive performance (hatching success, number of young fledged, and length of incubation) were improved. Concentrations of total polychlorinated biphenyls (PCBs) and planar PCB congeners in the eggs were compared between years. Median total PCB residue was 67% lower in 1988 (

A method for assessing environmental risk: A case study of Green Bay, Lake Michigan, USA

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A framework for incorporating stream use in the determination of priority watersheds.

=7.3 μg/g). This corresponds to a 42% reduction in tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ) from 1983 to 1988. We suggest that contaminant reduction and improved reproductive performance were due to low river flows in 1988 and associated reduced PBC loading into Green Bay. Forty-two percent of the matured chicks died before fledgling, and their body weight growth curves were much lower than normal. Young accumulate total PCBs at a rate of 17.6 μg/day. A no-observable-adverse-effects level (NOAEL) of 40–84 μg/kg/day was estimated from the two year results using the least observable adverse effects level (LOAEL)/NOAEL rating values.

Microcontaminants and reproductive impairment of the Forster's tern on Green Bay, Lake Michigan-1983

This study determined total number, biomass, taxa, and seasonal occurrence of adult aquatic insects emerging from four vegetation zones in one diked and one undiked freshwater coastal marsh on hypereutrophic lower Green Bay, Lake Michigan, USA during the summer of 1984. Floating box traps were placed in open water, sparse emergent, dense emergent, and wet meadow vegetation zones in each marsh. Insects were collected during 20 24-hour periods, each four days apart, from June 11 to August 26. Two-way ANOVA was used to test differences in number and biomass of insects between marshes and among vegetation zones. Polynomial regression was used to evaluate seasonal emergence patterns. More insects, insect biomass, and insect taxa were found in the diked marsh, especially during the first half of the sampling period. Damselflies were much more abundant in the diked marsh. Most insects and insect biomass were found in the sparse emergent vegetation zone of both marshes. The emerging insect community in the diked marsh appears enhanced by its separation from the hypereutrophic and turbid waters of lower Green Bay.

Ecotoxicology and ecosystem integrity: the Great Lakes examined

The Science Advisory Board of the US Environmental Protection Agency has recommended that risk reduction strategies become the centerpiece of environmental protection. The goal in developing such strategies is to identify opportunities for greatest reduction of ecological risks. This is a perspective that is significantly more comprehensive than the traditional focus on human health risks arising from environmental degradation. The identification of ecological risks upon which environmental protection efforts should be focused requires an ecological risk assessment methodology that is based on anthropogenic stressors affecting an ecosystem and a set of impaired use criteria. A methodology based on this concept is developed and discussed in this article. The methodology requires that risk values be assigned to each ecosystem stressor-impaired use pair that reflect the degree to which the given stressor contributes to ecosystem risk as measured by the given impaired use criterion. Once these data are available, mathematical analyses based on concepts from fuzzy set theory are performed to obtain a ranking of ecosystem stressors. The methodology has been tested by applying it to a case study involving Green Bay of Lake Michigan. A workshop was held in which 11 persons with extensive knowledge of the Green Bay ecosystem determined risk values through a group-consensus process. The analytical portion of the methodology was then used to rank the ecosystem risks (stressors) from several perspectives, including prevention management and remediation management. The overall conclusion of the workshop participants was that the fuzzy set decision model is a useful and effective methodology for differentiating environmental risk.

A graph-theoretic analysis of relationships among ecosystem stressors

Continued resource degradation in various areas of the Great Lakes has led to doubts of the adequacy of conventional science and management approaches. The need for a more holistic approach, identified as an ecosystem approach, appears now to be more widely accepted although progress with implementation is slow. We argue here that ecosystem science is an integral part of an ecosystem approach and is a prerequisite to effective management planning.One of the problems of implementing an ecosystem approach is forging the link between ecosystem based research and management. For Green Bay, Wisconsin, USA, certain structural and functional qualities of the ecosystem have been used to define operational guides and to formulate management objectives. These objectives are being utilized in the development of a remedial action plan for Green Bay.

An Assessment of Ecosystem Risks in the St. Croix National Scenic Riverway.

The identification of priority watersheds is an important component in planning activities associated with non-point source pollution abatement. The identification of priority watersheds is a complex issue at best, but it is made even more so in certain cases by the desire of water quality planners to take stream use into account when making decisions. Thus, for example, certain streams may be classified as potential sport fisheries, while others may be designated as suitable for tolerant forage fish. It may be the case that the impact of non-point source pollution upon one stream is less than that upon a second stream when viewed strictly in terms of the physical condition of the streams. Yet, when viewed from the standpoint of habitat suitability for different fish species, the priority judgement could be reversed. A methodological framework is presented which allows planners to take stream use into account in the determination of priority watersheds. The framework provides a formal structure for organizing non-point source data associated with specific watersheds and stream habitat data for various fish species in a manner suitable as inputs to two fuzzy set models. The fuzzy set models incorporate the imprecision and fuzziness characteristic of non-point source water pollution problems. In an illustrative application to the Kewaunee River Basin in Wisconsin, U.S.A., the methodology is used to identify priority watersheds when streams are categorized on the basis of potential fisheries.