Human-driven spatial and temporal shift in trophodynamics in the Gulf of Maine,USA

Utilizing marine protected areas (MPAs) to isolate the ecological effects of human influence can help us understand our effect on systems and foster ecosystem-based approaches to management. Specifically, examining invertebrate prey community dynamics inside and outside an MPA may provide a measure of how altering human influence (i.e., certain fishing pressures) affects ecosystem interactions. We measured trophic interactions inside and outside a deep-water temperate MPA over 2 years. Predation rates on tethered, preferred groundfish prey (crabs) were initially identical inside and outside the MPA, but decreased outside the MPA after the commercial groundfish fishing season commenced. Predation trials using a ubiquitous prey species (brittle stars) and a less preferred prey species (urchins) served as controls, showing no MPA effect. Our experiments quantify differential predatory activity resulting from differences in human activity driven by an MPA, demonstrating important effects of fishing and regulations on the strength of trophic interactions.     

PM Fine Standards and Implied Modeling/Analysis Needs

ABSTRACT

New National Ambient Air Quality Standards (NAAQS) were promulgated for fine particulate matter (FPM) in July 1997. This paper summarizes likely timing for implementing programs to meet these standards, which have a bearing on future modeling/analysis needs. The paper notes technical requirements implied by the nature of the NAAQS, as well as feedback the agency has received concerning modeling/analysis through Federal Advisory Committee Act (FACA) subcommittee work groups. Conclusions and recommendations drawn from recently completed U.S. Environmental Protection Agency (EPA)- sponsored workshops on modeling and other source attribution techniques are also described. Efforts to respond to needs implied by the NAAQS and feedback are noted by outlining major topics and issues that future guidance on use of modeling and other analyses used for attainment demonstrations will need to address. The paper concludes by highlighting several as yet unmet modeling/analysis needs to support a well-founded strategy for meeting air quality goals for FPM. These are suggested as potential areas for policy-relevant research.     

ZOOPLANKTON COMMUNITIES OF A NEW PUMPED STORAGE RESERVOIR1

ABSTRACT: Zooplankton colonization was followed for 16 months in Lake Oconee, Georgia, a new pumped storage reservoir. Data were interpreted to identify differences among stations and seasons, as a function of the reservoir's early stage of development and of pumped storage operations. Colonization was rapid, and the zooplankton community was characterized by a high species diversity; approximately 40 rotifer species and 14 cladoceran genera were recorded. Zooplankton density varied along an environmental gradient from riverine to lentic conditions. Rotifer abundance varied from 10⁴-10⁶ individuals/m³, with maxima in the summers Copepod and cladoceran densities ranged from 10³ to nearly 10⁵ individuals/m³; maxima for stations other than the dam were observed in the summer and early fall, but high values at the dam station occurred throughout winter 1980. When pumped storage operations began in December 1979, zooplankton densities increased at the dam station. Pumpback decreased the intensity of the environmental gradient from riverine to lentic conditions, and led to a more similar zooplankton community structure throughout the reservoir.     

Development of an immuno-immobilized androgen receptor assay (IRA) and its application for the characterization of the receptor binding affinity of different pesticides

Pesticides are synthetic chemicals used not only for improving food and feed production but also for the protection of materials and of human health and well-being. Some of these substances are suspected for adverse effects attributable to an interaction with the endocrine system of vertebrates by mimicking or inhibiting endogenous hormones. One of the biological targets important in this relation is the androgen receptor (AR). To be able to screen environmental samples for the presence of compounds which might interfere with androgen action, we aimed to develop a receptor assay based on recombinant human AR (rhAR). We herein describe an rhAR assay in which the receptor is immobilized in microtiter plates via a specific antibody. The assay can be used for high throughput screening of chemicals spread into the environment. 29 of the most recommended pesticides of the Federal Country Hessen, Germany, were tested for their ability to displace [3H]-DHT bound to the rhAR. This evaluation included the major part of the most common herbicides, insecticides and fungicides and covered three potential groups of endocrine disrupting chemicals. For 28 of the substances evaluated, the relative binding affinity to the rhAR was below 0.1% when compared to dihydrotestosterone (DHT) (100%), only fentinacetate exhibited an affinity of 1.42%. An exchange assay indicated that the binding inhibition was reversible. In consequence, fentinacetate seems to be a hormonally active substance which may be present in vegetables or fish, but also on clothing. We conclude that further investigations on this compound and its metabolites are necessary.     

Relief workers and violations of humanitarian law: Some legal considerations

This paper examines the various legal constraints upon action by relief workers when faced with violations of human rights or of humanitarian law. The unique status of the International Committee of the Red Cross (ICRC) and its delegates is explained and contrasted with the position of relief organizations and their personnel under the Geneva Conventions 1949 and their Additional Protocol I 1977. Proposals are made for the establishment of guidelines for action by relief workers when confronted with atrocities and for the training of relief workers in the relevant laws and procedures.