Suchergebnisse

Changes in the hormone regulation in animals due to environmental contaminants (endocrine disruptors) has recently become a widely investigated and politically charged issue. Invertebrates account for 95% of the known species of animals on earth, yet surprisingly little effort has been made to understand their value in signaling potential environmental endocrine disruption. A few reports, however, do suggest that endocrine disruptive effects also affect invertebrates. Due to the high pollutant load of the Scheldt estuary and North Sea, effects on resident populations may occur. A recent database published by our laboratory summarizes the possible effects of potential endocrine disruptive compounds for the North Sea ecosystem. Mysids are used frequently in toxicity studies and there is growing interest in developing toxicity tests with mysids that are indigenous to local ecosystems. Furthermore, United States Environmental Protection Agency (USEPA) has included mysid shrimp as part of a tiered approach in its Endocrine Disruptor Screening Program. In this context, we are examining the potential use of Neomysis integer as a test organism for determining the effects of endocrine disruptors on northern European estuarine communities. The hyperbenthic N. integer dominates the upper regions of European estuaries and are thought to provide a significant link in the exchange of organic matter between the benthic and pelagic systems of estuaries. Cellular and physiological biomarkers for endocrine disruption related to the energy and steroid metabolism of N. integer have been developed and are currently being evaluated in an inter-laboratory validation study. The results obtained with these biomarkers are linked to ecological field observations and measured concentrations of selected endocrine disruptors in the Scheldt estuary (Netherlands). Results of the biomarker studies and field samplings will be highlighted and suggestions on the use of this invertebrate model to test possible endocrine disruptive effects in estuarine environments will be discussed.

Anthropogenic chemicals that disrupt the hormonal systems (endocrine disruptors) of wildlife species recently have become a widely investigated and politically charged issue. Invertebrates account for roughly 95% of all animals, yet surprisingly little effort has been made to understand their value in signaling potential environmental endocrine disruption. This omission largely can be attributed to the high diversity of invertebrates and the shortage of fundamental knowledge of their endocrine systems. Insects and crustaceans are exceptions and, as such, appear to be excellent candidates for evaluating the environmental consequences of chemically induced endocrine disruption. Mysid shrimp (Crustacea: Mysidacea) may serve as a viable surrogate for many crustaceans and have been put forward as suitable test organisms for the evaluation of endocrine disruption by several researchers and regulatory bodies (e.g., the U.S. Environmental Protection Agency). Despite the long-standing use of mysids in toxicity testing, little information exists on their endocrinology, and few studies have focused on the potential of these animals for evaluating the effects of hormone-disrupting compounds. Therefore, the question remains as to whether the current standardized mysid endpoints can be used or adapted to detect endocrine disruption, or if new procedures must be developed, specifically directed at evaluating hormone-regulated endpoints in these animals. This review summarizes the ecological importance of mysids in estuarine and marine ecosystems, their use in toxicity testing and environmental monitoring, and their endocrinology and important hormone-regulated processes to highlight their potential use in assessing environmental endocrine disruption.

DIMAS is a 2-year project executed by three Belgian partners (EURAS, VLIZ and Ghent University) and funded by the SPSD II research program of the Belgian Science Policy (BELSPO). Several shipping accidents in Belgian territorial waters, made the various government agencies involved aware of the need to develop tools to assess the risks and impact on marine resources in the case of an accidental release of hazardous substances. DIMAS aims at the protection of the North Sea and Western Scheldt in case of accidental spills from ships. In the present project, a relational database is developed, providing reliable, easy to interpret and up-to-date information on marine specific issues. The database contains the latest information on effects (acute and chronic), absorption, distribution, bioaccumulation/biomagnification, GESAMP hazard profiles and physico-chemical properties for a selection of priority substances and is publicly available ( www.vliz.be/projects/dimas ). The selection of the substances is based on criteria such as occurrence on priority lists, volumes transported over sea, frequency of involvement in accidental spills and frequency of transports over sea. The first beneficiaries of this database are the people directly involved in the first phase of a containment plan for an accidental spill. The final indirect beneficiaries are the general public (scientists, journalists, general public, etc.) who will be better informed about the potential impact to man and the environment.