- Aquatics - Presented by: Rick Pattenden Mainstream Aquatics Ltd.

Presentation Outline Baseline Studies EIS Approach Significance of Impacts Fish Habitat Compensation Monitoring

Baseline Studies Approach Collect information that describes the aquatic biological community in sufficient detail to allow prediction of Project impacts. Baseline studies were not designed to collect pre- development information needed for monitoring Components Limnology, periphyton, phytoplankton, zooplankton, benthic invertebrates, fish, and fish habitat Effort Sampled lakes and streams during multiple years (1995 – 2000) and seasons (spring, summer, fall)

TypeTask GeneralLimnology **** Plankton **** Invertebrates **** Fish ***** Fish habitat ***** DetailedFish numbers *** Quantify fish habitats * ** Sampled Components

YearSeasonLakesStreams 1995Spring, summer, fall Spring, summer, fall Spring Spring, summer, fall Spring, summer, fall64 Sampling Effort

Results of Baseline Studies Lakes and streams in the Project area are typical of most waterbodies in Nunavut (cold, clear, and few nutrients) The aquatic communities are simple (few species) and exhibit low productivity (e.g., few fish and slow growth) Fish populations in the Project area are resident Most frequently encountered fish are lake trout, round whitefish, Arctic char, and slimy sculpin Most lakes in the Project area can support fish year round Most streams in the Project area are small and are used by fish only when there is flowing water

Environmental Impact Statement Approach Followed the requirements of the NIRB Environmental Impact Assessment Guidelines Fish were used as the Valued Ecosystem Component Impacts on other aquatic biota were examined indirectly through Project effects on fish Used a conservative definition for a significant impact A Project effect that causes a permanent change in the fish community

Potential impacts caused by Project Direct mortality of fish Loss of fish habitat Reduced water quality Environmental Impact Statement

What Project activities may cause impacts? 1. Use of explosives 2. Stream C1 diversion 3. Water intake causeway 4. Discharge from the PKCA 5. Mine site discharge during post-closure 6. Processed kimberlite containment area (PKCA)

Use of Explosives

Environmental Impact Statement 1.Use of explosives at the mine site The amount of explosives and detonation frequency will be reduced to minimize area of the impact zone Impact zone would be restricted to Stream C1 and a small portion of Carat Lake at the stream outlet Only fish eggs and not fish would be impacted (based on guidelines specified by DFO) Slimy sculpin would be the only affected species Are the impacts significant? - No

Stream C1 Diversion

Environmental Impact Statement 2. Stream C1 diversion at the mine site Diversion would be designed to ensure structural stability and to accommodate peak water flow The dewatered stream section is not used by fish Sediments would be introduced only during the initial filling of the diversion and during maintenance Impact of sediments would be restricted to the lower section of Stream C1 and a small portion of Carat Lake at the stream outlet Impact would occur infrequently Are the impacts significant? - No

Water Intake Causeway

Environmental Impact Statement 3.Water intake causeway Sediment introduction into Carat Lake during construction will be contained Causeway would be small (90 m long; 1325 m 2 ) Causeway would not destroy important fish habitat Altered water circulation would have minimal effects on adjacent fish habitats Are the impacts significant? - No

PKCA Discharge

Environmental Impact Statement 4.Discharge from the PKCA Potential water quality impacts would be mitigated before water enters Lake C3 Discharge would alter water flow in Stream C3 Impacted stream habitat is marginal value to fish based on DFO criteria Low numbers of fish that use the lower section of Stream C3 would be affected Are the impacts significant? - No

Mine Site Discharge Post-closure

Environmental Impact Statement 5.Discharge from the mine site post-closure Water quality of discharge may result in loss of fish habitat and reduced fish health in Carat Lake Impact would be mitigated by diluting the concentrations using a diffuser placed in the lake Impact would be restricted to the mixing zone immediately surrounding the diffuser (7 m radius) Impacted area is not important fish habitat and is not used by large numbers of fish Are the impacts significant? - No

PKCA FOOTPRINT

Environmental Impact Statement 6.Presence of the processed kimberlite containment area (PKCA) Would cause a permanent loss of fish habitat in the Long Lake system (Long Lake and two ponds) Populations of two species would be impacted (slimy sculpin and burbot) A fish salvage program would save some of the fish Are the impacts significant? - Yes

Environmental Impact Statement Importance of the Impact System provides marginal fish habitat compared to other fish-bearing lakes in the immediate vicinity small waterbodies just enough depth for fish to survive the winter Supports low numbers of only two species (slimy sculpin and burbot) From an ecological perspective, Long Lake is not as important as other fish-bearing lakes in the area If a lake must be impacted, Long Lake is the best choice

Environmental Impact Statement Are the impacts on aquatic biota significant? 1. Use of explosives – No 2. Stream C1 diversion – No 3. Water intake causeway – No 4. Discharge from of the PKCA – No 5. Mine site discharge during post-closure - No 6. Processed kimberlite containment area (PKCA) - Yes

Fish Habitat Compensation Approach Use methods that will produce the greatest benefit to fish and that will last after the mine is closed Use proven methods that meet DFO fish habitat compensation requirements Compensation Options Physically enhance fish habitat Improve fish access to critical habitats Mine pit enhancement

Fish Habitat Compensation Affected Area and Compensation Habitats Affected Area (m 2 ) Compensation (m 2 ) Ratio Streams (C1 and C3) 5681, Lake shore (Carat Lake) 1,4352, Lakes (Long Lake system) 92,500317, Total 94,653320,4853.4

Aquatics Effects Monitoring Approach Collect reliable information that will: allow detection of change caused by the Project test predictions of Project impacts Focus on components that are good indicators of change Use accepted sample design and methods Invest sufficient effort in order to detect change associated with the Project if one exists

Potential Impacts Monitored Nutrient loading Sedimentation Contaminants Monitoring Components Rate of sedimentation Periphyton Phytoplankton and zooplankton Benthic invertebrates Fish (metal contaminants) Aquatics Effects Monitoring