Proceedings - Teaching and Learning Centre - Simon Fraser ...
Proceedings - Teaching and Learning Centre - Simon Fraser ... Proceedings - Teaching and Learning Centre - Simon Fraser ...
Fraser River Action Plan 3rd Research Workshop Gobas: As new toxicology data becomes available (especially with respect to the complex nature of contaminant mixtures) it needs to be made available for use in some kind of framework for regulators. Farrell: We need to take a more hard-nosed approach: if contaminants kill fish, discharges must be shut off. Bendell-Young: There should be more focus on ecological studies; we need to know the life histories of these fish. There is enough dose-response information. Parrott: Both lab studies and an ecological approach are necessary. Culp: There exists an obvious need for serious thought on synthesis: how to integrate ecosystem and toxicology studies and take the information to the next (management/regulatory) level. Data Gaps/Recommendations • With respect to aquatic-based birds, further research on toxicological implication, particularly on endocrine system endpoints, from chlorinated compounds, as well as others such as nonyl-phenols. • Need to assess the degree of mobility of peamouth chub. • Continue to develop near-field evaluation techniques for sites with dramatic seasonal flow changes and habitat differences. Use of chub as sentinel species needs to be restricted to far-field zones until capture success improves. • Source and pathways for bioaccumulation in eagles and ospreys difficult to establish; seasonal movements of osprey need to be tracked. • Role of modifying factors in MFO induction (exercise, temperature, particle size/nature) needs to be resolved. Further laboratory induction tests to be made, using black liquor and field sources of sediments. • No comparative toxicity data for chlorinated phenolics for fish larvae other than white sturgeon. • Establish a B.C. source of sturgeon, standardized rearing and testing protocol for white sturgeon. • Cannot evaluate consequences of chlorophenol exposure to sturgeon without relevant environmental chemical concentrations and rate of chemical degradation. • Life history of white sturgeon must be studied. Page 310
Fraser River Action Plan 3rd Research Workshop General Conclusions Session 2: Transport and Sedimentation Chair: G. Lawrence The flocculation of biosolids with sediments is an important process, but difficult to model. • With pulp mills, concentration of contaminants definitely higher downstream than upstream. The main contaminant source is from biosolids. • The mechanism of contaminant transport is flocculation of biosolids with sediments. In the process of flocculation, biosolids settle out and are deposited leading to a significant reduction in sediment load moving downstream from the pulp mill. • Modeling of contaminant transport is very difficult. The physics of transport processes are complicated and site-specific, depending on the nature of outfall, location in river, proximity to river bends, turbulence, and temperature. • The potential for greatest effluent interaction occurs when the Fraser’s natural sediments are in approximately the same concentration as the biosolids. Whereabouts downstream this occurs is dependent on the nature of the diffuser. • Temperature of sediment/biosolid mixture and level of turbulence is very important in the flocculation process. • Size fractionation may help determine settling rates and to predict where flocs may eventually deposit, but the difficulty with this is that flocs that have formed in the water column and fallen toward the river bed encounter shear forces at the boundary layer which break them apart again. • During winter low flow periods, deposition occurs just downstream of discharges. During spring freshet, they are picked up again and dragged downstream. • We’re still far from formulating a powerful near-field model; hopefully we have enough information to get some empirical results. Discussion Sekela: Archiving field samples for the future is a good idea, but we have no definite plans yet. Gray: With regard to the flocculation process, aside from Kamloops Lake, do we have sites with contaminated sediment accumulating over periods greater than a year? Krishnappan: During base-flow periods (winter) you can get temporary storage of sediments, even in the middle of river, over a period of 4-6 months, and whether this duration is ecologically significant (how will it effect benthic organisms?) is something we should probably look into. Sekela: I don’t think bed sediments are the main problem — in the mainstem, sediment accumulation, at the longest, is on the order of 4-6 months and it is really a fall snapshot. Suspended sediments are more of an issue from a contaminant exposure point of view. The main problem is in winter when natural sediment load drops considerably, contaminant loading remains high and flocculation comes into play. Yunker: It is outside of the FRAP mandate, but we should keep in mind what the impact of the Fraser is on the Straight of Georgia. Group: (no comment) Page 311
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<strong>Fraser</strong> River Action Plan 3rd Research Workshop<br />
Gobas: As new toxicology data becomes available (especially with respect to the complex nature of<br />
contaminant mixtures) it needs to be made available for use in some kind of framework for regulators.<br />
Farrell: We need to take a more hard-nosed approach: if contaminants kill fish, discharges must be shut off.<br />
Bendell-Young: There should be more focus on ecological studies; we need to know the life histories of these<br />
fish. There is enough dose-response information.<br />
Parrott: Both lab studies <strong>and</strong> an ecological approach are necessary.<br />
Culp: There exists an obvious need for serious thought on synthesis: how to integrate ecosystem <strong>and</strong><br />
toxicology studies <strong>and</strong> take the information to the next (management/regulatory) level.<br />
Data Gaps/Recommendations<br />
• With respect to aquatic-based birds, further research on toxicological implication, particularly on<br />
endocrine system endpoints, from chlorinated compounds, as well as others such as nonyl-phenols.<br />
• Need to assess the degree of mobility of peamouth chub.<br />
• Continue to develop near-field evaluation techniques for sites with dramatic seasonal flow changes <strong>and</strong><br />
habitat differences. Use of chub as sentinel species needs to be restricted to far-field zones until capture<br />
success improves.<br />
• Source <strong>and</strong> pathways for bioaccumulation in eagles <strong>and</strong> ospreys difficult to establish; seasonal<br />
movements of osprey need to be tracked.<br />
• Role of modifying factors in MFO induction (exercise, temperature, particle size/nature) needs to be<br />
resolved. Further laboratory induction tests to be made, using black liquor <strong>and</strong> field sources of sediments.<br />
• No comparative toxicity data for chlorinated phenolics for fish larvae other than white sturgeon.<br />
• Establish a B.C. source of sturgeon, st<strong>and</strong>ardized rearing <strong>and</strong> testing protocol for white sturgeon.<br />
• Cannot evaluate consequences of chlorophenol exposure to sturgeon without relevant environmental<br />
chemical concentrations <strong>and</strong> rate of chemical degradation.<br />
• Life history of white sturgeon must be studied.<br />
Page 310
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