Proceedings - Teaching and Learning Centre - Simon Fraser ...

Fraser River Action Plan 3rd Research Workshop
Role of Particles in the Accumulation by
Fish of Chemicals from Pulp Mill Effluents
J.L. Parrott 1 , B.G. Krishnappan 1 and P.V. Hodson 2
1 National Water Research Institute
2 Department of Biology, Queens University
Abstract
Fish exposed to the spent cooking liquors from Kraft pulping (black liquor) demonstrated a linear increase in
liver mixed function oxygenase (MFO) activity (MFO induction). The interaction between chemical
accumulation by fish and the presence of particles in water was evaluated by bioassays of MFO induction with
trout exposed to black liquor in aquaria, stirred carboys, or in a large rotating flume that controlled bed shear
stress and hence, the number and size of particles. The extent of MFO induction should reflect the influence of
particles on chemical accumulation by fish. The null hypothesis was that particles would not reduce chemical
availability. Preliminary experiments with fish exposed in both the flume and in aquaria showed that fish could
survive in the flume if eddies were created to reduce swimming effort. However, MFO induction in the presence
of black liquor was much lower than expected based on parallel aquaria studies. High temperatures and exercise
appeared to reduce MFO induction caused by exposure to black liquor, so temperature controls were installed in
the flume to maintain 15°C, but the ‘flume effect’ persisted, suggesting some chemical adsorption to the walls of
the flume, or influence of exercise on fish MFO. Particles added to stirred aquaria (carboys) caused a reduction
in MFO induction by black liquor, which did not support the null hypothesis. These experiments were
preliminary and designed primarily to evaluate the best methods for testing fish in the flume. Fish exposures are
continuing using six newly constructed, stainless steel, linear flow channels. When built, these channels will be
used to test current speed effects on MFO. We will study the effects of particle concentrations and sources on
MFO induction by black liquor, using sediments from Nechako, Thompson and Main rivers.
Page 11