Research Product

Freshwater algae and vascular plants (macrophytes) have been used by aquatic ecologists for many years to monitor basic limnological characteristics and to determine the impact of pollution on ponds, lakes and rivers. Reviews of the various methodologies used in floristic surveys have been published by, among others, Shubert (1984) and Stevenson & Lowe (1986). In contrast to their use as bioindicator species, the use of aquatic plants as test species in laboratory toxicity tests has been less common than animal species such as daphnids and fish. For example, only 3% of the premanufacturer notices (PMN) required by the U.S. Toxic Substances Control Act(TSCA) have contained phytotoxicity data (Benenati, 1990). This is changing, however, due to increasing environmental regulations for chemicals in the USA (Holst & Ellwanger, 1982; US EPA, 1985a) and in the EC (OECD, 1984; EEC, 1987; ISO, 1987; Freemark et al., 1990). Phytotoxicity data are also considered for the development of water quality criteria (Stephen et al., 1985) and to evaluate the toxicities of dredge and fill material (US Army COE, 1989), food and drug additives (Eirkson et al, 1987) and industrial and municipal effluents (Laake, 1982; Weber et al, 1989). Overall, the ecological importance of freshwater plants and current regulatory expectations make them desirable test species in toxicity studies. This chapter reviews the current test methodologies and discusses the use of the results. The information presents an overview only; additional details are included in the references and are essential if the toxicity tests described are to be successfully conducted.