Page 995 - The Toxicology of Fishes

Estrogenic Effects of Treated Sewage Effluent on Fish in English Rivers 975

Rainbow trout
(Oncorhynchus mykiss)

A. River Stour (Kent) B. River Arun C. River Chelmer
Plasma VTG (ng/mL)

D. River Stour (Essex) E. River Lea F. River Aire
Plasma VTG (ng/mL)

FIGURE 25.3 Induction of vitellogenin in caged male rainbow trout (Oncorhynchus mykiss) placed in effluent channels
from sewage treatment works (effl.) and at various points upstream (up) and downstream of these discharges in 6 rivers in
England. Distances downstream from the sewage treatment works are given in kilometers. Fish were exposed for 3 weeks,
and the plasma was assayed for vitellogenin. Laboratory control (LC) fish were maintained for the same period of time in
bore-hole water in the laboratory. Open and solid bars represent pretreatment and posttreatment plasma vitellogenin
concentrations, respectively. Plasma vitellogenin concentrations are means ± SEM and are presented on a log scale.
Significant differences between pre- and post-exposures are shown (**p < 0.001). (Adapted from Harries, J.E. et al., Effects
of Trace Organics on Fish: Phase 2, Vol. FR/D 0022, report to the Department of the Environment Foundation for Water
Research, Marlow, U.K., 1995; Harries, J.E. et al., Environ. Toxicol. Chem., 16, 534–542, 1997.)

sewage treatment works in question handled mainly domestic effluent, but some (e.g., Marley STW,
which discharges into the River Aire) also received a small (up to 7%) proportion of industrial influent.
Adopting the same procedure as Purdom et al. (1994), caged rainbow trout were placed at various sites
in the rivers for a period of 3 weeks, and the plasma was subsequently assayed for VTG. In the stretches
of the rivers surveyed, no responses were seen in the Essex Stour, Kent Stour, or Chelmer (Harries et