PH24 Environmental Assessment, Environmental Toxicology
Exhibit Hall
8:00 AM - Thursday
(PH262) In situ anorexia in the Crustacean Macrobrachium rosenbergii as an ecological indicator of pesticide contamination in tropical aquatic ecosystems.
Satapornvanit, K.1, 2, 3, Baird, D.4, Little, D.1, 1 Institute of Aquaculture, University of Stirling, Stirling, Scotland, United Kingdom2 Faculty of Fisheries, Kasetsart University, Bangkok, Thailand3 Aquaculture and Aquatic Resources Management, Asian Institute of Technology, Pathumthani, Thailand4 NWRI/Environment Canada, University of New Brunswick, Fredericton, New Brunswick, Canada
ABSTRACT- Agricultural pesticides continue to be used by developing countries in increasing quantities as a result of increased globalisation of markets. Methods to assess the ecological effects of complex mixtures of pesticides are currently lacking in many tropical areas, and the approach presented in this paper forms part of a strategic project to develop such methods in SE Asia (EU-funded MAMAS Project). A key ecological effect of contaminant exposure is anorexia, which has implications for organism fitness and the functioning of food webs. Here we describe a bioassay based on this phenomenon, using postlarvae of the giant freshwater prawn (Macrobrachium rosenbergii), which are readily available from commercial hatcheries throughout the tropics. We exposed post-larvae (25-30 days after hatching) in the laboratory to 3 pesticides (Profenofos, Dimethoate, Chlropyrifos) and 1 metal (zinc). In all experiments, post-exposure feeding rates were significantly reduced when compared to controls. Using the method to expose animals in cages in agricultural drainage systems in central Thailand showed that in situ / ex situ feeding rates were also sensitive to pesticide contamination in the field, compared to the response at reference sites.
Key words: tropical ecotoxicology, Macrobrachium rosenbergii, ecological effect, feeding inhibition