STP865

    Calibration of Laboratory Bioassays with Results from Microcosms and Ponds

    Published: Jan 1985


      Format Pages Price  
    PDF Version (268K) 16 $25   ADD TO CART
    Complete Source PDF (3.8M) 16 $55   ADD TO CART


    Abstract

    Effects of an organic contaminant (a synthetic coal-derived crude oil) were measured in outdoor ponds and indoor pond-derived microcosms and compared with results of laboratory bioassays. Ponds and microcosms were treated with the oil continuously for eight weeks. Concentrations of phenolic compounds (the major water-soluble constituents of the oil) spanned the range of acute and chronic toxicity concentrations determined in single-species bioassays. Effects were similar in microcosms and ponds, implying that microcosms are suitable models for field studies for some purposes. Significant changes in community metabolism and zooplankton populations occurred in microcosms and ponds exposed to less than 0.05 mg/L phenols, near the 28-day lowest observed effect concentration (LOEC) for Daphnia magna. Ponds and microcosms were seriously damaged at concentrations near acute bioassay mean lethal concentration (LC50) values. Indirect effects in the ecosystems occurred at all treatment levels, and included changes in water quality, replacement of sensitive taxa by more tolerant competitors, and changes in abundance of some species because of increases or decreases in their predators or grazers. The safe exposure level determined from the ecosystem experiments was accurately predicted by an application factor of 0.03 in conjunction with the most sensitive acute bioassay result (the D. magna 48-h LC50). Less conservative extrapolation methods overestimated the safe concentration of this material in these ecosystems.

    Keywords:

    bioassays, microcosms, aquatic ecosystems, ponds, fish, insects, zoo-plankton, algae, aquatic toxicology, hazard assessment


    Author Information:

    Giddings, JM
    Research staff member and research associate, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN

    Franco, PJ
    Research staff member and research associate, Environmental Sciences Division, Oak Ridge National Laboratory, Oak Ridge, TN


    Paper ID: STP35257S

    Committee/Subcommittee: E47.01

    DOI: 10.1520/STP35257S


    CrossRef ASTM International is a member of CrossRef.