Toxkit technology and New Zealand water quality guidelines

Abstract

Toxkits are a relatively new generation of microbiotests developed by the research teams of Professor Guido Persoone at the University of Ghent, Belgium. They are an effective and cost-efficient way to perform, for example, regulatory acute aquatic toxicity screening tests of effluents, aimed at maintaining water quality and protecting biota of receiving waters. To date there are seven Toxkits on the market with different test species of different phylogenetic groups. The protocols for several of these kits (e.g., DaphtoxkitTM and the AlgaltoxkitTM) adhere to national or international guidelines for toxicity testing. Supported by the Sustainable Management Fund (SMF) of the Ministry for the Environment (New Zealand), research into the development of ecotoxicity test protocols using native indicator species has been underway since 1995 at the National Institute for Water and Atmospheric Research Ltd. NZ (NIWA). The Resource Management Act of 1991 requires local authorities and industry to apply for consent to discharge effluent to water or land. Ecotoxicity testing is now being included in these consent requirements. Also supported by a grant from the SMF, Wellington Polytechnic has begun comparative sensitivity tests, using split effluent samples, with Toxkit organisms and native species. NIWA is contracted to carry out the toxicity testing with native species. Six Toxkit protocols and the IQ Toxicity TestTM (rapid microbiotest using fluorescing enzyme split substrate) marketed by Aqua Survey USA are being used in the comparison. In addition a round-robin intercalibration exercise will be carried out using selected Toxkits, in regional diagnostic laboratories. Information from the comparative sensitivity tests and the intercalibration exercise will be used to determine overall effectiveness and cost-efficiency of the Toxkits, under New Zealand conditions, and to make recommendations to regional authorities about their potential role as Tier I ecotoxicity screening tests in consents to discharge effluent. The research design is explained, preliminary results are presented, and an update of recent advances in Toxkit technology and their increased application in European countries is given. © 1998 John Wiley & Sons, Inc. Environ Toxicol Water Qual 13: 337–345, 1998