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Potential Effects of Contaminants on Fraser River Sockeye Salmon

Potential Effects of Contaminants on Fraser River Sockeye Salmon

Potential Effects of Contaminants on Fraser River Sockeye Salmon

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Chapter 5 Evaluati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> <str<strong>on</strong>g>C<strong>on</strong>taminants</str<strong>on</strong>g> <str<strong>on</strong>g>of</str<strong>on</strong>g> C<strong>on</strong>cern5.0 Introducti<strong>on</strong>A preliminary evaluati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> the substances identified in the Inventory <str<strong>on</strong>g>of</str<strong>on</strong>g> Aquatic<str<strong>on</strong>g>C<strong>on</strong>taminants</str<strong>on</strong>g> was c<strong>on</strong>ducted to determine if <strong>on</strong>e or more chemicals <str<strong>on</strong>g>of</str<strong>on</strong>g> potential c<strong>on</strong>cernoccurred in envir<strong>on</strong>mental media within the <strong>Fraser</strong> <strong>River</strong> Basin at c<strong>on</strong>centrati<strong>on</strong>s sufficientto pose potential hazards to sockeye salm<strong>on</strong> (See Chapter 4 for more informati<strong>on</strong>). Thepreliminary evaluati<strong>on</strong> was c<strong>on</strong>ducted using the existing surface-water chemistry andwhole-sediment chemistry data from the study area. These data were evaluated usingtoxicity screening values from various sources. Because the c<strong>on</strong>centrati<strong>on</strong>s <str<strong>on</strong>g>of</str<strong>on</strong>g> <strong>on</strong>e ormore substances exceeded the toxicity screening values, it was c<strong>on</strong>cluded that chemicals<str<strong>on</strong>g>of</str<strong>on</strong>g> potential c<strong>on</strong>cern pose potential risks to aquatic organisms in the study area. Morespecifically, it was c<strong>on</strong>cluded the following substances represent c<strong>on</strong>taminants <str<strong>on</strong>g>of</str<strong>on</strong>g> c<strong>on</strong>cernin the <strong>Fraser</strong> <strong>River</strong> Basin:• C<strong>on</strong>venti<strong>on</strong>al variables (pH, TSS, turbidity);• Major i<strong>on</strong>s (chloride, fluoride, sulphate);• Nutrients (nitrate, nitrite, phosphorus);• Metals (aluminum, arsenic, bor<strong>on</strong>, cadmium, chromium, cobalt, copper, ir<strong>on</strong>,lead, mercury, nickel, selenium, silver);• Total phenols;• Polycyclic aromatic hydrocarb<strong>on</strong>s [acenaphthene, benz(a)anthracene,dibenz(a,h)anthracene]; and,• Plastics-related chemicals [bis(2-ethylhexyl)phthalate].Accordingly, a more detailed evaluati<strong>on</strong> was c<strong>on</strong>ducted to determine if <strong>on</strong>e or more <str<strong>on</strong>g>of</str<strong>on</strong>g>these c<strong>on</strong>taminants <str<strong>on</strong>g>of</str<strong>on</strong>g> c<strong>on</strong>cern occur at c<strong>on</strong>centrati<strong>on</strong>s sufficient to cause or substantiallyc<strong>on</strong>tribute to adverse effects <strong>on</strong> the survival, growth, or reproducti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> sockeye salm<strong>on</strong>in the <strong>Fraser</strong> <strong>River</strong> Basin. This evaluati<strong>on</strong> c<strong>on</strong>sisted <str<strong>on</strong>g>of</str<strong>on</strong>g> four main steps, including:• Refinement <str<strong>on</strong>g>of</str<strong>on</strong>g> the list <str<strong>on</strong>g>of</str<strong>on</strong>g> c<strong>on</strong>taminants <str<strong>on</strong>g>of</str<strong>on</strong>g> c<strong>on</strong>cern;• Selecti<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> salm<strong>on</strong>id-specific toxicity thresholds (or toxicity reference values);• Refinement <str<strong>on</strong>g>of</str<strong>on</strong>g> the exposure point c<strong>on</strong>centrati<strong>on</strong>s; and,• Calculati<strong>on</strong> <str<strong>on</strong>g>of</str<strong>on</strong>g> effect-based hazard quotients.56

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