Page 699 - The Toxicology of Fishes

Fish Toxicity Studies 679

When apparent steady state is reached, the BCF should be calculated as the geometric mean of BCFs
obtained during steady state, along with calculation of the 95% CI. If apparent steady state is not reached,
the BCF at the end of the uptake phase should be calculated. The uptake rate constant, depuration rate
constant, and projected steady-state BCFs and 95% CIs should be calculated using a model.
The BCFs and rate and extent of uptake and depuration depend on water quality, species (age and
size), physiological conditions, and other conditions. Furthermore, natural systems contain particulate
and colloidal matter not present in laboratory systems. Chemicals with low water solubilities will
substantially sorb to these types of matter in natural systems. Sorption will decrease the bioavailability
for some species but may increase the bioconcentration for other species that ingest particulate matter;
food may be an important source of chemical residues for certain fish. Bioconcentration tests with
chemicals should therefore consider other routes of chemical exposure; for example, test chemicals can
be incorporated into sediment or food or mixed with fine sediment particles. Fish with different behavioral
strategies should be used in bioconcentration tests.
Results of bioconcentration tests are important in assessing hazard and risk and in deriving sediment
and water quality. When designing an aquatic toxicology program, the type and extent of bioconcentration
and bioaccumulation testing depend on the characteristics and fate of the chemical, as well as the types
of exposure, target systems, and organisms affected.

Toxicity Testing: Summary

Toxicity testing with fish in the laboratory has many advantages. A well-designed testing program using
a variety of indigenous fish species with different behavioral strategies, natural water (including sedi-
ment), and realistic chemical exposures can be useful in hazard and risk management decisions. In spite
of the uncertainties and the fact that tests cannot be conducted under all possible exposure scenarios,
more realism can be incorporated into all toxicity regulatory requirements. In addition, because significant
biological activity may occur below the traditional NOECs, traditional regulatory tests should therefore
incorporate additional exposure concentrations at the low end of the concentration–response curve to
define this critical area. The public can easily relate to fish because of sport fishing and their economic
importance; therefore, when adverse effects on fish are observed, the public takes notice.

Acknowledgment
This is Southeast Environmental Research Center number 368.

References
Adams, W. J. (1995). Aquatic toxicology testing methods. In Handbook of Ecotoxicology, Hoffman, D. J.,
Rattner, B. A., Burton, G. A., and Cairns, Jr., J., Eds., Lewis Publishers, Boca Raton, FL, pp. 25–46.
American Public Health Association (APHA), American Water Works Association, and Water Pollution Control
Federation. (1960). Standard Methods for the Examination of Water and Wastewater, 11th ed. American
Public Health Association, New York.
American Society for Testing and Materials (ASTM). (2000). Standard practice for aquatic microcosms: fresh
water. ASTM E 1366-96. In Annual Book of ASTM Standards 2000. Section 11. Water and Environmental
Technology. Vol. 11.05. Biological Effects and Environmental Fate; Biotechnology; Pesticides. American
Society for Testing and Materials, Philadelphia, PA.
Belding, D. L. (1927). Toxicity experiments with fish in reference to trade waste pollution. Trans. Am. Fish.
Soc., 57, 100–119.
Bliss, C. I. (1934a). The methods of probits. Science, 79, 38–39.
Bliss, C. I. (1934b). The method of probits: a correction. Science, 79, 409–410.
Buikema, A. L., Niederlehner, B. R., and Cairns, Jr., J. (1982). Biological monitoring. Part IV. Toxicity testing.
Water Res., 16, 239–262.