Ammonia toxicity to larval copepods in eutrophic marine ecosystems: A comparison of results from bioassays and enclosed experimental ecosystems

• Published in: Aquatic toxicology 1985-01, Vol.7 (3), p.205-217
• Main Authors: Sullivan, Barbara K., Ritacco, P.J.
• Format: Article
• Language: English
• Subjects: Acartia hudsonica; Acartia tonsa; ammonia toxicity; Animal, plant and microbial ecology; Applied ecology; Biological and medical sciences; copepods; Ecotoxicology, biological effects of pollution; eutrophic marine ecosystems; Fundamental and applied biological sciences. Psychology; Marine; Marine and brackish environment
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/S0166-445X(85)80006-0

In an experiment designed to simulate eutrophication of a shallow coastal ecosystem, nutrients were added to experimental ecosystems (MERL mesocosms) in six different treatment levels. We observed large reductions in the numbers of normally dominant copepods of the species Acartia tonsa and A. hudsonica associated with high concentrations of unionized ammonia (NH 3) in the two most nutrient enriched treatments. Comparison of 48 h LC 50 values of 10–15 μM·l −1 NH 3 obtained from laboratory bioassays with concentrations of NH 3 associated with increased mortality in the MERL tanks indicated that bioassay data correctly predicted trends of high and low mortality as well as fluctuations in the numbers of copepods in MERL tanks. Actual mortality rates of the mesocosm copepods was sometimes higher than predicted, however.