Survey
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
* Your assessment is very important for improving the workof artificial intelligence, which forms the content of this project
DEPARTMENT for ENVIRONMENT, FOOD and RURAL AFFAIRS Research and Development CSG 15 Final Project Report (Not to be used for LINK projects) Two hard copies of this form should be returned to: Research Policy and International Division, Final Reports Unit DEFRA, Area 301 Cromwell House, Dean Stanley Street, London, SW1P 3JH. An electronic version should be e-mailed to [email protected] Project title Procedures for Reproductive Risk Evaluation Based on Diagnostic and Innovative Cellular Tools (Predict) DEFRA project code AE1118 Contractor organisation and location Plymouth Marine Laboratory Total DEFRA project costs Project start date £ 24,6215 01/10/97 Project end date 01/04/01 Executive summary (maximum 2 sides A4) Executive Summary Assessing the harmful impact of chemical contaminants on the health of the coastal marine environment is part of MAFF’s remit; and is a major scientific and conceptual challenge in the light of the comprehensive list of chemicals identified by OSPAR as potentially problematical (OSPAR Strategy with regard to Hazardous Substances; Ref No. 1998-16). The major aim of this proposal was to examine the effects of contaminant chemicals on the developing and free eggs from marine mussels in order to provide reliable and simple diagnostic tests of harmful effect that are predictive of reduced egg viability, i.e. as an indicator of detriment. In addition, since eggs reside in the plankton for several weeks, during which time they are likely to be exposed to organic chemical contaminants (xenobiotics) and UVB radiation, the impact of these two stressing factors and their interactions was assessed on the biota. The predictive capability of diagnostic tools for selected endpoints such as cellular and physiological pathology of eggs and larvae was also evaluated and modelled in relation to the physical characteristics of the pollutant chemicals (Quantitiative Strucure Activity Relationships, QSARs). Methods used included lysosomal stability (neutral red retention), which is now internationally recognised as an indicator of health status of the individual animal. Other methods were the multidrug resistance membrane transporter system ( an indicator of contaminant exposure), and larval development bioassays. The project objectives were modified and refocused during the course of the investigation, in agreement with the Project Officer. The overall thrust of the research in the original proposal was directed towards the study of contaminant effect on eggs whereas the research undertaken has been CSG 15 (Rev. 6/02) 1 Project title Procedures for Reproductive Risk Evaluation Based on Diagnostic and Innovative Cellular Tools (Predict) DEFRA project code AE1118 greatly extended to consider impacts on both eggs and early life stages. In addition, the original programme of research on UVB radiation effects was restricted to eggs and larvae of invertebrates whereas, and as a result of collaborative research with CEFAS, this area of work was greatly extended to include larval stages of both invertebrates and fish. These changes in focus have represented a considerable increase in research effort which has had consequences for other areas of work, notably the field work which was restricted to a single population, within the programme. Despite living in contaminated environments, some invertebrates can successfully reproduce, develop and grow. It is this ability to tolerate cocktails of contaminants that has lead researchers to conclude that certain marine invertebrates possess defence mechanisms against chemical insult. A mechanism similar to mammalian cell multidrug resistance (MDR) has been reported in aquatic organisms including the embryonic stages. Recent studies have shown that this MDR phenotype, or component of it, is part of a highly conserved system among the various phyla. Cells exhibiting the MDR phenotype generally show a decreased intracellular drug accumulation and a lack of responsiveness to a variety of natural and synthetic toxic compounds. Inhibitors of the MDR system, such as such as the drug verapamil (MDR-associated ATPase inhibitor), can circumvent this resistance. Accumulation of fluorescent MDR transportable dyes such as rhodamine-B have been measured and shown to be verapamil- sensitive. Larval stages of mussels have been successfully deployed for environmental impact assessments in support of cellular and physiological biomarkers and this study has demonstrated the presence of the MDR transporter system in the early life stages of mussels. Spawning of many commercially important fish and shellfish occurs in coastal waters, where larval stages reside in the upper water column, with the potential risk of exposure to anthropogenic contaminants and UV-B radiation. Their relative inactivity and absence of thick protective shells or scales enhance their vulnerability to radiation. This highlights the potential threat of increasing levels of UV-B for commercial fisheries and the aquaculture industry in temperate regions. Quantitative structure-activity relationship (QSAR) studies on six chemicals, including 5 environmental contaminants, showed that toxicity was significantly correlated with molar refractivity, an indicator of interaction with biological molecules. Weaker trends were observed for lipid solubility, molecular area and molecular volume. The behaviour of all of the contaminants was predicted by a QSAR-based model/data support system. N.B- Please see Technical Report for further information CSG 15 (Rev. 6/02) 2 Project title Procedures for Reproductive Risk Evaluation Based on Diagnostic and Innovative Cellular Tools (Predict) DEFRA project code Scientific report (maximum 20 sides A4) CSG 15 (Rev. 6/02) 3 AE1118