Cadmium in aquatic microcosms: implications for screening the ecological effects of toxic substances

Journal Article · Mon Nov 01 00:00:00 EST 1982 · Environ. Manage.; (United States)

DOI:https://doi.org/10.1007/BF01868383· OSTI ID:5680537

Hendrix, P F; Langner, C L; Odum, E P

A two-phase set of experiments was conducted to address some of the problems inherent in ecological screening of toxic substances in aquatic microcosms. Phase I was a 4 x 4 factorial experiment dealing with the interactive effects of cadmium and nutrients in static microcosms. Phase II was a 2 x 4 factorial experiment using flowthrough microcosms to study temporal aspects of system behavior in response to nutrient loading and chronic versus acute cadmium perturbations. Nutrient enrichment resulted in increased biomass and metabolic activity in both static and flowthrough microcosms. Cadmium treatments generally resulted in a decrease in abundance of grazing crustaceans and a subsequent increase in community respiration, suggesting a change in community structure from a grazing to a detritus food chain. Of the variables measured, community metabolism, community composition, and output/input ratios of nitrate-nitrogen were the most useful indicators of system response to cadmium. Nutrient enrichment reduced the effects of cadmium. For screening the ecological effects of toxic chemicals, a series of experiments is proposed, including 1) relatively simple static microcosms, 2) flow through microcosms, and 3) more detailed but selective studies in microcosms derived from specific ecosystems. Each step yields increasingly more information and serves as a guide for subsequent experiments; in addition, each step more closely approximates natural ecosystems.

• Research Organization: Univ. of Georgia, Athens
• OSTI ID: 5680537
• Journal Information: Environ. Manage.; (United States), Vol. 6:6
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
AQUATIC ECOSYSTEMS
MICROCOSMS
CADMIUM
BIOLOGICAL EFFECTS
METABOLISM
WATER POLLUTION
BIOLOGICAL INDICATORS
CRUSTACEANS
ECOLOGY
ENVIRONMENTAL IMPACTS
NUTRIENTS
POPULATION DENSITY
RESPIRATION
ANIMALS
AQUATIC ORGANISMS
ARTHROPODS
ECOSYSTEMS
ELEMENTS
INVERTEBRATES
METALS
POLLUTION
560304* - Chemicals Metabolism & Toxicology- Invertebrates- (-1987)