taiga shield ecozone - manitoba hydro · regions, while total island area increasedon -system...

Churchill

T a i g a S h i e l d E c o z o n e

BradshawTerrestrial

Region

Upper ChurchillTerrestrial

RegionSouthern IndianTerrestrial

Region

HZ 4

HZ 6

HZ 5

ReindeerLake

LacBrochet

River

Churchill

Lake

River

BigSandLake

Little

Indian

Southern

TadouleLake

Churc

hill

Hudson Bay

NorthernIndianLake

GauerLake

FidlerLake

C o a s t a l H u d s o n B a y

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W e s t e r n B o r e a lS h i e l d E c o z o n e

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Province of Manitoba, Government of Canada,ECOSTEM and Manitoba Hydro

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LegendEcozone

Terrestrial Region

Hydraulic Zone (HZ)

RCEA Region of Interest

Flow Direction

InfrastructureRail

Highway

Manit

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Sask

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Taiga Shield Ecozone Terrestrial Regions and

Hydraulic Zones

Hudson Bay

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NOTE: Not all hydroelectric footprints are shown.

Map 6.5.5-1

REGIONAL CUMULATIVE EFFECTS ASSESSMENT – PHASE II LAND – COLONIAL WATERBIRDS

DECEMBER 2015 6.5-35

6.5.5.1.2 After Hydroelectric Development

COLONIAL WATERBIRD HABITAT

The detailed hydraulic conditions of the major lakes and rivers in the Taiga Shield Ecozone can be found in Part IV, Physical Environment (Water Regime, Sections 4.3.3.2 and 4.3.3.3). In general, the CRD had considerable impacts to the aquatic system in the ecozone. It increased water levels on Southern Indian Lake by 9 ft (2.7 m) and flooded 55 square miles (140 km2) of land. Additionally, downstream of the Missi Falls Control Structure, water flows in the lower Churchill River were considerably reduced, with on average 27,000 cfs (780 cms) diverted into the Nelson River system from the Churchill River (Water Regime, Section 4.3.3.3). Median flow is much lower, and minimum licensed open-water flow is 500 cfs (14 cms). The number and total area of potential nesting islands decreased in the Taiga Shield Ecozone following hydroelectric development (Table 6.5.5-1; Map 6.5.5-2). Despite the reduction in the number of islands, in some terrestrial regions, including the Bradshaw and Upper Churchill terrestrial regions, total island area increased by 3 ha in each terrestrial region (Table 6.5.5-1). In the Southern Indian Terrestrial Region, total island area decreased by 59 ha, with the loss of approximately 100 islands of this type (Table 6.5.5-1). Detailed maps of colonial waterbird habitat in each terrestrial region are found in Appendix 6.5B.

The number of potential nesting islands decreased in the Bradshaw and Upper Churchill terrestrial regions, while total island area increased on-system (Table 6.5B-3). Additionally, the number and area of potential nesting islands decreased in the Southern Indian Terrestrial Region (Table 6.5B-3).

Table 6.5.5-1: Regional Colonial Waterbird Habitat Pre- and Post-hydroelectric Development in the Terrestrial Regions of the Taiga Shield Ecozone

Terrestrial Region or Ecozone

Number of Islands

Pre-Hydro 1

Area (ha) of Islands

Pre-Hydro

Number of Islands Post-

Hydro 2


Post-Hydro

% Change in Island Area

Bradshaw 1,412 222 1,385 225 1.1

Upper Churchill 1,315 617 1,229 620 0.4

Southern Indian 1,911 1,360 1,808 1,301 -4.3

Taiga Shield Ecozone 4,638 2,199 4,422 2,145 -2.5

1. Pre-hydroelectric development. 2. Post-hydroelectric development.

Hudson CoastTerrestrial

Region

RCEAArea 3

Fox LakeCree Nation

York FactoryFirst Nation

Fox LakeCree Nation

War LakeFirst NationIlford (NAC)

O-Pipon-Na-PiwinCree Nation

South Indian Lake

TataskweyakCree Nation

Long Spruce G.S.

LimestoneG.S.

Kettle G.S.

ConawapaG.S.

Barrington

Lake

Opachuanau

Big

Lake

Sand

Lake

Southern

Indian

Lake

TadouleLake

BaldockLake

Northern

LakeThorsteinson

Gauer

Lake

Lake

Indian

Lake

North

Knife

Fidler

Lake

LakeWaskaiowaka

StephensLake

River

LeafRapids

BradshawTerrestrial

Region

Upper ChurchillTerrestrial

Region

Southern IndianTerrestrial

Region

Waterbird Habitat Quality Taiga Shield EcozoneECOSTEM Ltd.

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Legend

Waterbird Habitat Quality

Generating Station (Potential)

Infrastructure

Transmission Line (Existing)

HighwayRail

Generating Station (Existing)

Transmission Line (UnderConstruction)07-OCT-15

Manitoba Hydro; Government of Manitoba; Government of Canada;ECOSTEM Ltd.

Primary Habitat (Off-system)

NOTE: Habitat polygons exaggerated slightly to enhance visibility.

Primary Habitat (On-system)

Terrestrial RegionRCEA Region of Interest

Map 6.5.5-2



Water flows measured at the Missi Falls Control Structure from 1979 to 2014 provide context for the number of extreme high-water events that could have affected colonial nesting waterbirds in the lower Churchill River channel. Typically, water flow rates through the Missi Falls Control Structure are around 500 cfs (Water Regime, Figure 4.4.2-3). However, during excess precipitation or significant run-off upstream, the Missi Falls Control Structure may release water into the lower Churchill River rather than diverting it. The release of water causes extreme high-water events downstream and potentially, locally devastating effects to nesting birds. From 1979 to 2014, water flows of 5,000–15,000 cfs occurred 10 times, suggesting that colonial waterbirds nesting in the river channel were exposed to a low risk of having their nests inundated. Water flows of 20,000–30,000 cfs occurred six times during the same period, indicating a moderate risk of nest inundation. Water flows of 40,000–60,000 cfs occurred once during this period, and most likely, indicating a high risk of nest inundation, and most likely, wiping out production in that year. The effects on colonial waterbird nests by these flow rates is unknown as it can vary based on the number of colonial waterbirds nesting on islands in the Churchill River, and the location and total area of island habitats inundated. Data such as these were not available for assessment purposes. The risk categories for nest inundation are based on professional judgement.

COLONIAL WATERBIRD POPULATION

No published information or publicly available ATK exists describing the population of colonial waterbirds in the Taiga Shield Ecozone.

Data from the Manitoba Breeding Bird Atlas indicated that the Bonaparte’s gull, ring-billed gull, and common tern was widespread in the Taiga Shield Ecozone. Breeding presence ranged from possible to confirmed for these three species (Manitoba Breeding Bird Atlas 2015).

6.5.5.2 Cumulative Effects of Hydroelectric Development

6.5.5.2.1 Regional Effects

INDICATOR RESULTS

Following hydroelectric development, the distribution of islands and total island area changed. A total of 216 potential colonial waterbird nesting islands were lost and the total area of nesting islands decreased by 2.5% in the Taiga Shield Ecozone following hydroelectric development. Based on the benchmarks used for the RCEA, overall habitat loss in the ecozone is considered moderate (1–10%).The number of islands in the Bradshaw and Upper Churchill terrestrial regions decreased, but the total area of islands increased by 1.1% and 0.4%, respectively. The Southern Indian Terrestrial Region experienced the largest decrease in potential nesting islands, with total island area decreasing by 4.3%.

EVALUATION OF EFFECTS

Prior to hydroelectric development, colonial waterbird habitat was more abundant in the Taiga Shield Ecozone. According to the regional habitat model and the benchmarks used for the RCEA, habitat loss in the ecozone is considered moderate (1–10%), with most of the losses located in the Southern Indian



Terrestrial Region. Islands suitable for nesting by colonial waterbirds were lost in the Churchill River and Southern Indian Lake as a result of the CRD. Lowered water levels in the Churchill River caused islands to become larger as portions of the islands that were previously underwater became exposed. This resulted in fewer, larger islands in the Bradshaw and Upper Churchill terrestrial regions. Lowered water levels also resulted in islands becoming connected to the mainland or may have caused islands to become too large to be suitable as nesting habitat. It is also likely that reefs and small islands were exposed in dewatered areas. Due to islands becoming larger and the creation of newly exposed islands/reefs, there was an overall gain in habitat in the Bradshaw and Upper Churchill terrestrial regions. However, the location and number of the islands currently used by nesting colonial waterbirds is unknown.

The quantity of islands identified as potential nesting habitat is likely lower than the habitat model predicted. Vegetation and soil type on the islands created following hydroelectric development is unknown, but both are conditions relating to nesting habitat suitability. It is likely that many of the islands created consisted of peatland soil, which would not provide suitable nesting habitat. Potential nesting islands composed of peatland tend to disintegrate over time as a result of erosion, or may float, move, and eventually become submerged. The disappearance of peat islands over time would result in a decrease in the number of islands previously identified as colonial waterbird nesting habitat. It is estimated that about 20% (or a similarly low proportion) of the islands in Southern Indian Lake are peat islands. The creation of peat islands is likely limited to the Southern Indian Terrestrial Region, due to the extensive overland flooding that occurred.

In Southern Indian Lake, water levels increased as a result of the CRD and a relatively large number of existing colonies and potential nesting islands were inundated and lost in the Southern Indian Terrestrial Region. Under extreme high-water events, wind seiches and wave action events may become more intense and increase the risk of nest inundation for those colonial waterbirds birds that may nest on Southern Indian Lake.

Events such as the periodic release of large volumes of water down the Churchill River through the Missi Falls Control Structure may have devastating local effects on the production of colonial waterbirds with the flooding and loss of nests. The overall reduction in available nesting islands and considerable changes to the lower Churchill River likely caused a long-term shift in habitat use by colonial waterbirds to other suitable areas in the Taiga Shield Ecozone or elsewhere.

REGIONAL CUMULATIVE EFFECTS CONCLUSION

Hydroelectric development in the Taiga Shield Ecozone had a substantial effect on colonial waterbirds. The CRD resulted in the loss of potential nesting islands in the Southern Indian Terrestrial Region due to increased water levels, and a loss of potential nesting islands in the Upper Churchill Terrestrial region due to decreased water levels. The cumulative effect of these changes on the colonial waterbird populations was likely considerable. As original nesting islands were either inundated or exposed by lower water levels, colonial waterbirds were likely forced to use other suitable, newly created islands for nesting within the ecozone, or to travel elsewhere to find suitable nesting habitat. However, the value of the newly created islands to colonial waterbirds is unknown. It is likely that over time, as erosion and high water levels occurred, island suitability for nesting colonial waterbirds increased wherever bedrock or gravel



substrate was exposed. Low quality islands formed of peat were not likely to be used by colonial waterbirds for nesting. The presence and development of transmission lines throughout the ecozone may increase the risk of collision mortality for colonial waterbirds in the vicinity of these lines However, the relatively low amount of mortality from bird-wire collisions would not considerably affect colonial waterbird populations in the ecozone, especially as few transmission lines intersect colonial waterbird nesting habitat. The degree to which regional colonial waterbird populations have been affected is not discernible. While local effects were likely marked, it appears colonial waterbird populations still tend be numerous and widespread throughout northern Manitoba.

6.5.5.2.2 Local Effects

The lowered water levels in the Churchill River and the increased water levels in Southern Indian Lake likely had considerable impacts on colonial nesting waterbirds in those areas. The loss and alteration of nesting habitat likely resulted in local breeding populations shifting their habitat use to suitable habitat found elsewhere in the ecozone or further away. In addition to the changes in nesting habitat, the large water level changes would have altered the aquatic environment on which the birds depend, likely also considerably affecting colonial waterbirds.



6.5.6 Hudson Plains Ecozone The Hudson Plains Ecozone contains a number of hydroelectric and non-hydroelectric developments. Some of the major hydroelectric developments in the ecozone include the Kettle, Long Spruce, and Limestone generation projects, as well as the Henday Converter Station. While the construction and start of operation of these projects spans several decades, 1966 is the year considered as the cut off for the pre-hydroelectric development period in this ecozone, marked by the start of construction on the Kettle GS. Non-hydroelectric development in this region is limited, and includes a portion of the Hudson Bay Railway.

Map 6.5.6-1 outlines the terrestrial regions found within the Hudson Plains Ecozone, overlain with the Hydraulic Zones used in the physical and aquatic environment portions of the RCEA Phase II report.

6.5.6.1 Changes in Indicators over Time Due to the absence of long-term colonial waterbird population data in the ecozone, the amount and distribution of colonial waterbird habitat was the indicator used to examine the impacts of hydroelectric development. Results and comparisons to current habitat availability are presented in Section 6.5.6.1.2. Available information on colonial waterbird populations in the ecozone was included to provide additional context to the analysis.

6.5.6.1.1 Before Hydroelectric Development

On-system island data are only available for the Limestone Rapids Terrestrial Region for the pre-hydroelectric development period. Within the Limestone Rapids Terrestrial Region, a total of 173 islands, covering 71 ha, were available to colonial nesting waterbirds pre-hydroelectric development (Table 6.5.6-1).

Published information and publicly available ATK are lacking regarding colonial waterbird populations in the ecozone prior to hydroelectric development. Godfrey (1966) indicated that island-nesting species such as common tern were locally common summer residents and transients in their breeding distribution throughout Canada. Herring gull was broadly distributed and tended to be common to abundant during migration. Ring-billed gull breeding range in Manitoba was limited to the upper portion of the Nelson River, but this species has greatly expanded its range and numbers since the 1980s (Godfrey 1986).

H u d s o n P l a i n sE c o z o n e

E a s t e r n B o r e a l S h i e l dE c o z o n e

C o a s t a l H u d s o n B a y E c o z o n e

T a i g a S h i e l dE c o z o n e

C o a s t a l H u d s o n B a yE c o z o n e

River

Nelso

n Haye

sRiv

er

StephensLake HZ 11

HZ 12

HZ 10

Limestone Rapids

Terrestrial Region Deer Island

Terrestrial Region

Kettle G.S.

Limestone G.S.

Long Spruce G.S.

Conawapa G.S.

HUDSONBAY

Keeyask G.S.

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Rail

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Hudson Plains Ecozone Terrestrial Regions and

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Hudson Bay

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Map 6.5.6-1





The detailed hydraulic conditions of the major lakes and rivers in the Hudson Plains Ecozone can be found in Part IV, Physical Environment (Water Regime, Sections 4.3.4.3 and 4.3.4.4). In general, the forebays of the Long Spruce and Limestone GSs were largely contained within the natural banks of the Nelson River, resulting in the flooding of 5.6 square miles (14.5 km2) and 0.8 square miles (2.2. km2), respectively (Water Regime, Section 4.3.4.3). No hydroelectric developments occur downstream of the Limestone GS, and effects on the lower Nelson River are limited to those caused by upstream developments (Water Regime, Section 4.3.4.4).

Two islands, covering 6 ha, were lost in the Limestone Rapids Terrestrial Region following hydroelectric development (Table 6.5.6-1). Colonial waterbird habitat was relatively limited on-system in the Deer Island Terrestrial Region, consisting of three islands in the post-hydroelectric period (Table 6.5B-1; Map 6.5.6-2). Habitat comparisons cannot be made for the Deer Island Terrestrial Region as pre-hydroelectric data were not available (Table 6.5B-4).

Table 6.5.6-1: Regional Colonial Waterbird Habitat Pre and Post-hydroelectric Development in the Terrestrial Regions of the Hudson Plains Ecozone


Number of Islands

Pre-Hydro 1


Pre-Hydro

Number of Islands

Post-Hydro 2


Post-Hydro


Limestone Rapids 173 71 171 65 -7.7

Deer Island 148* 29* 151 33 N/A

Hudson Plains Ecozone N/A N/A 322 98 N/A

1. Pre-hydroelectric development. 2. Post-hydroelectric development. * Only includes off-system habitat data.


The majority of data and information regarding colonial populations in the ecozone comes from the environmental studies conducted to support the planning of the potential Conawapa Generation Project. Information from other generating stations in the area (e.g., Kettle, Long Spruce, and Limestone) is absent due to a lack of environmental studies for these projects.

ShamattawaFirst

Nation

Deer IslandTerrestrial

RegionLimestone RapidsTerrestrial

Region

LongSpruce

G.S.

LimestoneG.S.

KettleG.S.

ConawapaG.S.

290

280

280

280

Lake

HeppellBishopLake

Munk

LRankine

Laforte

Crosswell

Lake

TurcotteL

Deer

Whiting

MistakeL

L

Lake

Cygnet

CygnetLittle

L

Hawes

AtkinsonL

KettleLake

Wilson

R

Lake

River

LMyre

Strobus LWeir

Lake

LongLake

L

LakeOwl

Fly

River

River

LandingHead

Ck

Red PlaceRapids

Running

Rapids

RiverCreek

Creek

LimestoneRapids

River

Dog

Ck

Moose

Horn

Lost

Cooper

Weir

Kettle

LongSpruce

Angling

Rapids

Creek

Rapids

North

Fox

River

Angling

AnglingL

Creek

Silcox

Owl

Creek

Creek

Ck

Hoot

Beale

Kelsey

Steele

Lake

Creek

Fletcher

Hannah

WhiteBrownMaryLake

L

L

LakeSutton

SalmonLake

Creek

SkidmoreBroad

River

LakeDewar

River

River

BrotenLake

RiverMerrick

Lake

LakeFifer

River

LakeBastable Pennycutaway

LakePanco

Seal

Noochewaywun

Rupert

Lake

RiverCreek

Ck

LNapper

Creek

White

Creek

Black

North

Bear

Seal

Ck

Gods

River

River

Shilling

Ten

Ck

PortNelson

Creek

CreekBear

MarshPoint

Creek

French

LakeRobidoux

CarusoLake

RiverWigwam

Ck

Creek PannebakerCreek

Machichi

Fountain

Menahook

River

Tawns

CkRiver

Adie

Creek

PryorLake

Fox Lake Cree Nation

Fox LakeCree Nation

ShamattawaFirst Nation

Gillam

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Waterbird Habitat Quality Hudson Plains Ecozone

NOTE: Habitat polygons exaggerated slightly to enhance visibility.

LegendTerrestrial Region

RCEA Region of InterestWaterbird Habitat Quality

Primary Habitat (Off-system)Primary Habitat (On-system)



Highway

Rail

Transmission Line (Existing)Transmission Line (Under Construction)

Map 6.5.6-2



Didiuk (1975) conducted boat surveys along the lower Nelson River from Limestone Rapids to Gillam Island. In total, 100 gulls were observed on the river, which were mainly herring gull, ring-billed gull, and Bonaparte’s gull. One common tern colony, consisting of 120 adults, was observed on a small gravel island, approximately 5 km downstream of Limestone Rapids and other islands were noted to provide potential nesting habitat (Didiuk 1975). I.D. Systems Ltd. (1989, 1990) stated the lower Nelson River and its tributaries supported a low density and abundance of gulls and terns, however no data or reason (e.g., low habitat quality) were provided to support that assertion. Recent environmental studies for the potential Conawapa Generation Project suggest that the lower Nelson River provides breeding habitat for several species of gulls and terns (TetrES 2005a, 2006, 2008a, 2009a, 2010; Stantec 2011a, 2014a).

TetrES/Stantec monitored colonial waterbird numbers monthly from June until October on the Nelson River from 2004 to 2009, and in 2011 and 2013; and on the Hayes River from 2005 to 2008, and in 2011 and 2013. Average waterbird densities were highest on the Long Spruce GS forebay (average of 11.1 birds/km2) and lowest on the Hayes River (1.3 birds/km2). Waterbird densities were relatively high in June surveys (3.0–14.6 birds/km2), peaked in July (2.1–14.9 birds/km2), began to decrease in August (0.3–14.8 birds/km2), and declined further in September (0.2–9.9 birds/km2) and October (0.1-8.3 birds/km2) (TetrES 2005a, 2006, 2008a, 2009a, 2010; Stantec 2011a, 2014a). Generating station infrastructure and rocky islands within the main channel of the Nelson River were the preferred habitat where most gulls and terns were observed (TetrES 2008a).

Seven potential nesting colonies of gulls were observed in the Nelson River during the waterbird surveys from 2004 to 2013. Four nesting colonies were observed on the islands and reefs in the Limestone GS tailrace area, near the mouth of the Limestone River. Two nesting colonies of gulls were located on the southern tip of Jackfish Island in the Nelson River. These nesting colonies supported 200–250 pairs of ring-billed gulls and the area was used annually from 2005 to 2013 when surveys were conducted. One nesting colony was observed in the Limestone GS forebay (Figure 6.5.6-1) (TetrES 2006, 2008a, 2009a; 2010; Stantec 2011a, 2014a).

Data from the Manitoba Breeding Bird Atlas indicated that the Bonaparte’s gull was widespread in the Hudson Plains Ecozone, while other species such as the ring-billed gull and common tern were sparse. Breeding presence ranged from possible to confirmed for these three species (Manitoba Breeding Bird Atlas 2015). The apparent low numbers of some species may be due to a lack of sampling effort in remote areas rather than low numbers of birds.



Figure 6.5.6-1: Gull and Tern Nesting Colonies in the Hudson Plains Ecozone Post-hydroelectric Development (Stantec 2014a)





INDICATOR RESULTS

Following hydroelectric development, it is unclear whether the distribution of islands and total island area changed in the Hudson Plains Ecozone. Two potential nesting islands, covering 6 ha (7.7% of total island area), were lost in the Limestone Rapids Terrestrial Region as a result of hydroelectric development. The amount of habitat change in the Deer Island Terrestrial Region is not known due to the absence of habitat data pre-hydroelectric development. A comparison to the benchmarks was not possible for the ecozone due to the absence of on-system habitat data for the pre-hydroelectric period in the Deer Island Terrestrial Region.


Prior to hydroelectric development, colonial waterbird habitat was more abundant on the Nelson River. A comparison to the benchmarks was not possible for the ecozone due to the absence of on-system habitat data for the pre-hydroelectric period in the Deer Island Terrestrial Region. At least two islands were inundated as a result of water-level regulation, resulting in a loss of colonial waterbird habitat and causing a shift in habitat use to other suitable areas in the ecozone or beyond. It is also possible that a limited amount of nesting habitat, such as reefs or small islands, were exposed or formed in dewatered areas below generating stations (e.g., Limestone GS) that could have offset some of the nesting habitat losses, but this cannot be confirmed with the available data.

Current water-level regulation may also affect available nesting habitat. Daily water levels may vary by 2-3 ft (0.6–0.9 m) in the Long Spruce GS and Limestone GS forebay, and by as much a 6 ft (1.8 m) just downstream of the Limestone GS (Water Regime, Section 4.3.4.3). The daily cycling of water was not likely present pre-hydroelectric development and has the potential to impact nesting colonial waterbirds by temporarily inundating potential nesting islands.


Loss and alteration of colonial waterbird habitat has likely occurred in the Hudson Plains Ecozone as a result of water-level regulation from numerous hydroelectric developments on the Nelson River. Operation of the CRD was likely responsible for the greatest change to colonial waterbird habitat even though it occurred outside the ecozone, as it increased water levels throughout the Nelson River. Further water level increases caused by the impoundment of water by the Long Spruce GS and Limestone GS also reduced the amount of potential nesting habitat to colonial waterbirds. The cumulative effect of these changes on the colonial waterbird populations was likely marginal, reducing the amount of potential nesting and brood-rearing habitat available and likely caused a shift in habitat availability within the ecozone. The presence and development of transmission lines throughout the ecozone may increase the risk of collision mortality for colonial waterbirds in the vicinity of these lines. However, the relatively low



amount of mortality from bird-wire collisions would not considerably affect colonial waterbird populations in the ecozone, especially as few transmission lines intersect colonial waterbird nesting habitat. The degree to which regional populations have been affected is not discernible. The local effects were likely considerable, although it appears colonial waterbird populations today still tend be numerous and widespread throughout the ecozone as demonstrated in recent environmental surveys.


Local effects on colonial waterbird habitat are unclear due to the absence of data prior to hydroelectric development. Increased water levels in the Nelson River likely reduced the amount of colonial waterbird habitat available. The loss or alteration of nesting habitat likely resulted in local breeding populations shifting their habitat use to other suitable habitat found elsewhere in the ecozone or further away.

Prior to, during and after the breeding season, waterbird species such as ring-billed gull and common tern are often observed foraging for fish in the tailrace areas immediately downstream of the Limestone GS and Long Spruce GS. The turbulent waters likely provide increased feeding opportunities, including live and dead fish that are present near the surface.



6.5.7 Coastal Hudson Bay Ecozone The Coastal Hudson Bay Ecozone contains little hydroelectric or non-hydroelectric development. The major hydroelectric developments located in the ecozone are the Churchill Weir and the Radisson to Churchill transmission line. Despite few hydroelectric developments, the lower Churchill River has been considerably altered due to upstream developments (i.e., the CRD). The pre-hydroelectric development period in this ecozone is defined as occurring before the operation of the CRD in 1976. The Churchill Weir was operational in 1999. Major, non-hydroelectric developments in the ecozone includes the town and port of Churchill and a portion of the Hudson Bay Railway.

Map 6.5.7-1 outlines the terrestrial regions found within the Coastal Hudson Bay Ecozone, overlain with the Hydraulic Zones used in the physical and aquatic environment portions of the RCEA Phase II report.

6.5.7.1 Changes in Indicators over Time Due to the absence of long-term colonial waterbird population data in the ecozone, the amount and distribution of colonial waterbird habitat was the indicator used to examine the impacts of hydroelectric development. Results and comparisons to current habitat availability are presented in Section 6.5.7.1.2. Available information on colonial waterbird populations in the ecozone was included to provide additional context to the analysis.


Prior to hydroelectric development in the Coastal Hudson Bay Ecozone, 1,786 islands, covering 655 ha, were available to colonial nesting waterbirds (Table 6.5.7-1). The majority of on-system islands (73%) were located in the Warkworth Terrestrial Region (Table 6.5.6-1).

Webb and Foster (1974) evaluated the potential impacts on wildlife prior to the development of the CRD. They noted several species of gulls and terns breeding in the lower Churchill River area, and observed small breeding colonies on lakes, in particular a small colony of common tern on Fidler Lake. The large fluctuations in water levels resulting from development of the CRD was predicted to make successful nesting impossible for colonial waterbirds on the lower Churchill River (Webb and Foster 1974).

Gillam

Churchill

Long SpruceG.S.

Limestone G.S.KettleG.S.

KeeyaskG.S.

ConawapaG.S.

C o a s t a l H u d s o n B a yE c o z o n e

T a i g a S h i e l dE c o z o n e

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The detailed hydraulic conditions of the major lakes and rivers in the Coastal Hudson Bay Ecozone can be found in Part IV, Physical Environment (Water Regime, Section 4.3.3.3). In general, the CRD has had considerable impacts on the ecozone. The flow of the Churchill River has been reduced from an average of approximately 40,000 cfs to 10,000 cfs due to the CRD (Water Regime, Section 4.3.3.3). Median flow is much lower, and minimum licensed flow is 500 cfs. The Churchill Weir was constructed to mitigate some of the effects of the CRD. The weir increased water levels by 6.6 ft (2.0 m) in its vicinity with water-level effects extending upstream approximately 6.2 mi (10 km) (Water Regime, Section 4.3.3.3).

According to the regional habitat model, the number of islands in the Hudson Coast and Warkworth terrestrial regions decreased following hydroelectric development, while the number of islands increased in the Fletcher Terrestrial Region (Table 6.5.6-1). Approximately 2 ha and 38 ha of island habitat were lost in the Hudson Coast and Warkworth terrestrial regions, respectively, as a result of rewatering from the Churchill Weir. However, 23 ha of colonial waterbird habitat was gained in the Fletcher Terrestrial Region as water levels in the lower Churchill River were lowered, exposing potential nesting habitat as a result of the CRD. The Churchill Weir did not rewater the river in this terrestrial region (Table 6.5.7-1; Map 6.5.7-2).

According to on-system data, approximately half of the islands in the Hudson Coast and Warkworth terrestrial regions were lost post-hydroelectric development, while the number of islands in the Fletcher Terrestrial Region increased 10-fold (Table 6.5B-5).

Table 6.5.7-1: Regional Colonial Waterbird Habitat Pre and Post-hydroelectric Development in the Terrestrial Regions of the Coastal Hudson Bay Ecozone


Number of Islands

Pre-Hydro 1


Pre-Hydro

Number of Islands

Post-Hydro 2


Post-Hydro


Hudson Coast 432 288 405 286 -0.8

Warkworth 533 205 445 168 -18.3

Fletcher 821 162 862 185 14.0

Coastal Hudson Bay Ecozone 1,786 655 1,712 638 -2.6


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Region

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Region

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Information regarding colonial populations in the ecozone comes from the environmental studies conducted to support the planning of the Churchill Weir and the potential Conawapa Generation Project.

Numerous species of gulls and terns are common in the Churchill River estuary during the breeding season. Common species observed in the area include the arctic tern (Sterna paradisaea), Bonaparte’s gull, herring gull, and ring-billed gull (McLaren et al. 1977; TetrES 1996, 1997, 1998a). Other, uncommon species observed in the area include the Ross’s gull (Rhodostethia rosea), arctic tern, little gull (Hydrocoloeus minutus), Iceland gull (Larus glaucoides), glaucous gull (Larus hyperboreus), Thayer’s gull (Larus thayeri), Sabine’s gull (Xema sabini), and parasitic jaeger (Stercorarius parasiticus) (Chartier 1994; TetrES 1996, 1998a; Manitoba Breeding Bird Atlas 2015).

As part of the environmental studies for the Churchill Weir, portions of the lower Churchill River were monitored for colonial waterbirds prior to (1995–1997) and after (1999–2003) construction. In 1995, prior to the construction of the weir, 26 nesting colonies of arctic terns and 18 nesting colonies of herring gulls were observed along the lower Churchill River. These nesting colonies contained from one to 50 breeding pairs and one to 20 breeding pairs, respectively (TetrES 1996; The Town of Churchill and Manitoba Hydro 1997). The construction of the Churchill Weir in the Churchill River was anticipated to displace 20-50 pairs of arctic terns and one to three pairs of herring gulls, as construction would eliminate a small gravel island in the river (The Town of Churchill and Manitoba Hydro 1997). As mitigation, in 1998, an island, approximately 0.1 ha in size was constructed in the rewatered area (the area up to 10 km upstream from the weir) to provide alternative nesting habitat. The island, known as Bird Island, was monitored for colonial waterbird bird use until 2003 (TetrES 1998a). Bird Island provided effective mitigation for the habitat loss and alteration caused by operation of the weir (TetrES 1998b; 2000). Numerous colonial waterbirds were observed nesting on the island, including little gulls, which are considered a rare species in North America (TetrES 1998a, b, 2000, 2001, 2002; Chartier 2002, 2004).

TetrES/Stantec monitored colonial waterbird numbers monthly from June until October in the Nelson River and Hayes River estuaries from 2005 to 2009, and in 2011 and 2013; and along the shoreline of Hudson Bay (from Port Nelson to Rupert’s Creek) from 2007 to 2009, and in 2011 and 2013. Average waterbird densities were highest on the in the Nelson River Estuary and Hudson Bay coastline (average of 12 birds/km2 in each) and lowest in the Hayes River Estuary (5 birds/km2). Waterbird densities were relatively high in June surveys (1–11 birds/km2), peaked in July (16–28 birds/km2), began to decrease in August (3–20 birds/km2), and declined further in September (1–5 birds/km2) and October (1–8 birds/km2) (TetrES 2005a, 2006, 2008a, 2009a, 2010; Stantec 2011a, 2014a).





INDICATOR RESULTS

Following hydroelectric development, the distribution of islands and total island area changed considerably in the Coastal Hudson Bay Ecozone. A total of 74 potential colonial waterbird nesting islands, totaling 17 ha, were lost in the ecozone as a result of hydroelectric development. Potential nesting islands were lost in the Hudson Coast and Warkworth terrestrial regions, with total island area decreased by 0.8% and 18.3%, respectively. The number of potential nesting islands increased in the Fletcher Terrestrial region, with total island area increasing by 14%. Based on regional habitat model and the benchmarks used, habitat loss is considered moderate (1–10%) in the ecozone.


Prior to hydroelectric development, colonial waterbird habitat was more abundant in the Coastal Hudson Bay Ecozone. Islands likely suitable for nesting by colonial waterbirds were lost in the lower Churchill River following the development of the CRD upstream of the ecozone, and the development of the Churchill Weir. The lower water levels in the lower Churchill River caused by the CRD likely increased the number of potential nesting reefs and islands. In turn, the development of the Churchill Weir increased water levels in a smaller portion of the Churchill River, which inundated islands in the Hudson Coast and Warkworth terrestrial regions, thereby reducing the amount of colonial waterbird habitat available. The loss of colonial waterbird nesting islands was partially and successfully mitigated for through the construction of a nesting island (Bird Island) near the Churchill Weir. Bird Island supported numerous nesting waterbirds, including rare species such as the little gull. In 2014, although island use by gulls is unknown, it is still physically present in the river and it affords gulls and terns with potentially high quality nesting habitat. Islands in the Fletcher Terrestrial Region remained exposed as the Churchill Weir did not raise water levels high enough to affect islands further upstream. The overall effects on colonial waterbirds were probably small as only 17 ha of islands were lost. There was likely a shift in habitat use by colonial waterbirds following hydroelectric development, particularly in the Hudson Coast and Warkworth terrestrial regions, where most habitat loss and alteration occurred. This cannot be definitive, given the lack of information on active nesting sites, both pre-and post-hydroelectric development.


Loss and alteration of potential colonial waterbird habitat has occurred in the Coastal Hudson Bay Ecozone as a result of water level regulation from hydroelectric developments. The cumulative effect of these changes on colonial waterbird populations was likely small. The reduction and alteration of potential nesting and brood-rearing habitat available likely caused a shift in habitat use within the ecozone as was observed with the use of Bird Island following operation of the Churchill Weir. The degree to which regional populations have been affected is not discernible. The presence and development of transmission lines throughout the ecozone may increase the risk of collision mortality for colonial waterbirds in the vicinity of these lines However, the relatively low amount of mortality from bird-wire



collisions would not substantially affect colonial waterbird populations in the ecozone, especially as few transmission lines intersect colonial waterbird nesting habitat. While local effects were likely marked on specific nesting colonies, it appears colonial waterbird populations today still tend be numerous and widespread throughout the ecozone as demonstrated in recent environmental surveys.


The large changes in water levels in the Churchill River from the CRD and the Churchill Weir likely had considerable local effects on colonial nesting waterbirds in the ecozone. The loss and alteration of nesting habitat likely resulted in local breeding populations shifting their habitat use to suitable habitat found elsewhere in the ecozone or potentially, further away. Mitigation efforts, such as the construction of Bird Island, helped to alleviate the effects of the Churchill Weir on colonial waterbird populations, but was limited to a relatively small area in the lower Churchill River. In addition to the changes in nesting habitat, the changes to the aquatic environment likely had substantial effects on colonial waterbirds.



6.5.8 Effects of Hydroelectric Development in the Region of Interest on Colonial Waterbirds

• The amount of potential nesting habitat for colonial waterbirds is, and has been, variable between ecozones within the RCEA ROI. Currently, the Eastern Boreal Shield Ecozone contains 58% of potential nesting islands in the RCEA ROI (Table 6.5.8-1). Other ecozones, including the Boreal Plains, Hudson Plains, and Coastal Hudson Bay ecozones, provide a relatively low amount of potential colonial waterbird nesting habitat in comparison (Table 6.5.8-1).

• Based on the assessment, both the Coastal Hudson Bay and Taiga Shield ecozones lost potential nesting sites following hydroelectric development: 2.6% and 2.5% of total island area, respectively.

• Overall, the amount of potential colonial waterbird nesting habitat increased in the RCEA ROI following hydroelectric development (Table 6.5.8-1). o This was largely a result of increased water levels on some major river systems, including the

Rat, Burntwood and Nelson rivers. As water levels increased in the river systems due to the diversion or retention of water from hydroelectric development, existing, low-lying islands were likely inundated, while simultaneously, small elevated areas of land lost their connection with the mainland to form new islands.

o The suitability of these islands to colonial waterbirds for nesting has not been substantiated due to the absence of detailed vegetation and soil data.

o It is likely that the habitat model used in this study as an indicator of colonial waterbird population health overestimated the number of potential nesting islands because an unknown proportion of the newly created islands were likely unsuitable as colonial waterbird nesting habitat.

o It is probable that on some islands, over time, erosion and decreased depth to groundwater eliminated vegetation on some proportion of these islands, and increased their suitability for nesting colonial waterbirds.

• The overall impacts of hydroelectric development within the RCEA ROI are somewhat in contrast to local impacts observed. Local knowledge largely indicates that colonial waterbird habitat was lost throughout the Nelson and Burntwood river systems due to increased water levels. o Nesting colonies that existed pre-hydroelectric development were likely inundated by increasing

water levels in some on-system areas, resulting in the loss of nesting habitat in the areas observed. Potential colonial waterbird nesting habitat remained relatively abundant in the wider off-system area.

o While long-term population data on colonial waterbird populations in the RCEA ROI were not available, through the observations of recent environmental studies, it appears that colonial waterbirds are still abundant in the RCEA ROI post-hydroelectric development, both on and off the regulated system.

o Despite the loss of existing nesting islands, the creation of new islands likely provided colonial waterbirds with enough other suitable nesting habitat that populations overall were not substantially affected.



• Hydroelectric development has also resulted in regulated water levels in some areas, reducing the amount of water level variation in some major river system and waterbodies. o Reduced water-level variation may occasionally benefit colonial waterbirds as there is a

possibility that a nesting colony might otherwise be inundated during periods of unusually high water, causing complete nest failure. In a natural-state system, high water periods are typically driven by local precipitation and upstream runoff, which may be relatively unpredictable. In a regulated system, such as the Nelson River, water levels are maintained within certain limits despite local precipitation and upstream runoff.

o Alternatively, water level fluctuations in a natural-state system may be able to provide additional habitat to colonial waterbirds during years of low water as reefs and islands become exposed. Small reefs and islands are important nesting habitat for colonial waterbirds.

• In addition to habitat changes, the relatively low level of mortality from bird-wire collisions would not substantially affect colonial waterbird populations in the RCEA ROI. Although it is not known how many colonial waterbird nesting colonies are located in proximity to transmission lines, the probability of nesting islands being adjacent to transmission lines is low, as few transmission lines cross large rivers or lakes where colonial waterbird nesting islands are located.

• The cumulative effects of hydroelectric development on colonial waterbirds in the RCEA ROI appear to be relatively low and do not appear to have had an appreciable effect on populations. Colonial waterbirds appear to be able to find and use other suitable nesting habitat elsewhere within the RCEA ROI. When combined with appropriate mitigation (e.g., the creation of Bird Island upstream of the Churchill Weir), the redistribution of colonial waterbirds is limited and the effects of hydroelectric development are reduced.

Table 6.5.8-1: Modeled Colonial Waterbird Habitat Pre- and Post-hydroelectric Development in the Ecozones in the RCEA Region of Interest

Ecozone Number of

Islands Pre-Hydro 1


Pre-Hydro

Number of Islands Post-

Hydro 2


Post-Hydro % Change in Island Area

Western Boreal Shield

4,720 2,338 5,319 2,853 22.0

Eastern Boreal Shield

14,209 7,606 16,300 8,322 9.4

Boreal Plains 58 30 58 30 0.0

Taiga Shield 4,638 2,199 4,422 2,145 -2.5

Hudson Plains N/A N/A 322 98 N/A

Coastal Hudson Bay

1,786 655 1,712 638 -2.6

Total 25,732 12,928 28,133 14,086 9.0




6.5.9 Bibliography

6.5.9.1 Literature Cited and Data Sources AMEC Environment and Infrastructure. 2015. Manitoba Hydro Bipole III Transmission Project – 2014

avian monitoring report. February 2015. 72 pp.

Avian Power Line Interaction Committee. 2012. Reducing avian collisions with power lines: the state of the art in 2012. Edison Electric Institute and APLIC, Washington, DC. 159 pp.

Barrientos, R., Alonso, J. C., Ponce, C., and Palacin, C. 2011. Meta-analysis of the effectiveness of marked wire in reducing avian collisions with power lines. Conservation Biology 25(5): 893–903 pp.

Bevanger. K. 1994. Bird interactions with utility structures: collision and electrocution, causes and mitigating measures. IBIS 136: 412–425 pp.

Bevanger, K. 1998. Biological and conservation aspects of bird mortality caused by electric power lines: a review. Biological Conservation 86: 67–76 pp.

Brown, K. M., and Morris, R. D. 1996. From tragedy to triumph: renesting in ring-billed gulls. The Auk 113(1): 23–31 pp.

Bunn, S. E., and Arthington, A. H. 2002. Basic principles and ecological consequences of altered flow regimes for aquatic biodiversity. Environmental Management 30(4): 492–507 pp.

Burger, J., and Gochfeld, M. 1991. The common tern. Its breeding and biology and social behaviour. Columbia University Press, New York, NY. 413 pp.

Burgess, N.M., and Meyer, M. W. 2008. Methylmercury exposure associated with reduced productivity in common loons. Ecotoxicology 17: 83–91 pp.

Chartier, B. 1994. A Birder’s Guide to Churchill. American Birding Association Inc., Denver, CO. 132 pp.

Chartier, B. 2002. Lower Churchill River weir project — 2002 terrestrial monitoring survey results. Churchill Wilderness Encounter. 47 pp.

Chartier, B. 2004. Lower Churchill River weir project — 2003 terrestrial monitoring survey results. Churchill Wilderness Encounter. 54 pp.

Cree Nation Partners. 2012. Keeyask environmental evaluation report: a report on the environmental effects of the proposed Keeyask Project on Tataskweyak Cree Nation and War Lake First Nation. 78 pp.



Crowder, M.R., and Rhodes, Jr, O. E. 2002. Relationships between wing morphology and behavioural responses to unmarked power transmission lines. In The Seventh International Symposium on Environmental Concerns in Rights-of-Way Management. Edited by J. W. Goodrich-Mahoney, D. F. Mutrie and C. A. Guild. Elsevier, Boston, MA. 403–410 pp.

Didiuk, A.B. 1975. Fish and wildlife resources impact assessment, lower Nelson River, Manitoba. Research Branch, Manitoba Department of Mines, Resources and Environmental Management, Winnipeg, MB. 239 pp.

Dunn, E. K. 1975. The role of environmental factors in the growth of tern chicks. Journal of Animal Ecology 44 (3): 743–754 pp.

Environment Canada. 2004. Threats to water availability in Canada. NWRI Scientific Assessment Report Series No. 3 and ACSD Science Assessment Series No. 1. National Water Research Institute, Burlington, ON. 128 pp.

Environment Canada. 2010. Mercury in the food chain [online]. Available from http://www.ec.gc.ca/mercure-mercury/default.asp?lang=en&n=d721ac1f-1 [accessed April 17, 2012].

Forman, R. T. T., and Alexander, L. E. 1998. Roads and their major ecological effects. Annual Review of Ecology, Evolution, and Systematics 29: 207–231 pp.

Fox Lake Cree Nation. 2012. Environment Evaluation Report. September 2012.

Godfrey, W. E. 1966. The Birds of Canada. Bulletin No. 203. Biological series No. 73. National Museum of Canada, Ottawa. ON.

Godfrey, W. E. 1986. The Birds of Canada. Revised Edition. National Museum of Natural Sciences, National Museums of Canada, Ottawa, ON.

Goulden, R. C., Bossenmaier, E. F., Van Zyll de Jong, C. G., and Howard, J. L. 1968. Implications of the Churchill River Diversion to wildlife. Manitoba Department of Mines, Resources and Environmental Management, Winnipeg, MB. 34 pp.

Heinz, G. H., Hoffman D. J., Klimstra, J. D., Stebbins, K. R., Kondrad, S. L., and Erwin, C. A. 2009. Species differences in the sensitivity of avian embryos to methylmercury. Archives of Environmental Toxicology 56: 129–138 pp.

Henderson, I. G., Langston, R. H. W., and Clark, N. A. 1996. The response of common terns (Sterna hirundo) to power lines: an assessment of risk in relation to breeding commitment, age and wind speed. Biological Conservation 77: 185–192 pp.

I.D. Systems Ltd. 1989. Conawapa project — environmental impact assessment — all weather road. August 1989. 80 pp.

I.D. Systems Ltd. 1990. Conawapa project — environmental impact assessment — construction power transmission line. March 1990. 55 pp.



Ivey, G., and Herziger, C. P. 2006. Intermountain west waterbird conservation plan, Version 1.2. A Plan associated with the Waterbird Conservation for the Americas Initiative. U.S. Fish and Wildlife Service Pacific Region, Portland, OR. 205 pp.

Jackson, T. A. 1988. The mercury problem in recently formed reservoirs of northern Manitoba (Canada): effects of impoundment and other factors on the production of methyl mercury by microorganisms in sediments. Canadian Journal of Fisheries and Aquatic Sciences 45: 97–121 pp.

Jacobson, S. L. 2005. Mitigation measures for highway-caused impacts to birds. PSW-GTR-191. USDA Forest Service General Technical reports. 1043–1050 pp.

Keeyask Hydropower Limited Partnership. 2012. Keeyask Generation Project: environmental impact statement: response to EIS guidelines. Keeyask Hydropower Limited Partnership, Winnipeg, MB. 1,200 pp.

Kirkham, I. R., and Morris, R. D. 1979. Feeding ecology of ring-billed gull (Larus delawarensis) chicks. Canadian Journal of Zoology 57 (5): 1086–1090 pp.

Kushlan, J. A. 1993. Colonial waterbirds as bioindicators of environmental change. Colonial Waterbirds 16: 223–251 pp.

Kushlan J. A., Steinkamp, M. L., Parsons, K. C., Capp, J., Acosta-Cruz, M., Coulter, M., Davidson, I., Dickson, L., Edelson, N., Elliot, R., Erwin, R. M., Hatch, S., Kress, S., Milko, R., Miller, S., Mills, K., Paul, R., Phillips, R., Saliva, J. E., Sydeman, B., Trapp, J., Wheeler, J., and Wohl, K. 2002. Waterbird Conservation for the Americas: the North American Waterbird Conservation Plan, Version 1. Waterbird Conservation for the Americas, Washington, DC. 78 pp.

Manitoba Breeding Bird Atlas. 2015. [online]. Available from http://www.birdatlas.mb.ca [accessed August 24, 2015].

Manitoba Hydro and NCN (Nisichawayasihk Cree Nation). 2003a. Wuskwatim Generation Project environmental impact statement, Volume 7 Resource Use, Section 2. 41 pp.

Manitoba Hydro and NCN. 2003b. Wuskwatim Transmission Project: wildlife environment, supporting document, Volume 4. Prepared for Manitoba Hydro and Nisichawayasihk Cree Nation by TetrES Consultants Inc., Winnipeg, MB. 127 pp.

McLaren, P. L., McLaren, M. A., and Patterson, L. A. 1977. Numbers and distributions of birds during migration in the district of Keewatin, northern Manitoba and northwestern Ontario, 1976. Prepared for Polar Gas Project, LGL Limited-Environmental Research Associates. 323 pp.

Morris, R. D., and Hunter, R. A. 1976. Factors influencing desertion of colony sites by common terns (Sterna hirundo). Canadian Field-Naturalist 90: 137–143 pp.

Parnell, J. F., Ainley, D. G., Blokpoel, H., Cain, B., Custer, T. W., Dusi, J. L., Kress, S., Kushlan, J. A., Southern, W. E., Stenzel, L. E., and Thompson, B. C. 1988. Colonial waterbird management in North America. Colonial Waterbirds 11: 129–169 pp.



Rioux, S., Savard, J. P. L., and Gerick, A. A. 2013. Avian mortalities due to transmission line collisions: a review of current estimates and field methods with an emphasis on applications to the Canadian electric network. Avian Conservation and Ecology 8(2): 7 pp.

Stantec (Stantec Consulting Ltd.). 2011a. Conawapa generation project — Avian 2008 field studies report. Environmental studies program report # TERR-08-01. 201 pp.

Stantec. 2011b. Wuskwatim Generation Project terrestrial effects monitoring program avian studies, 2011. Report # 11-03. Prepared for the Wuskwatim Power Limited Partnership by Stantec Consulting Ltd., Winnipeg, MB. 94 pp.

Stantec. 2014a. Conawapa generation project — Avian 2013 field studies report. Environmental studies program report # TERR-13-01. Stantec Consulting Ltd., Winnipeg, MB. 144 pp.

Stantec. 2014b. Keeyask Generation Project avian 2013 field studies report. Report # 13-02. Stantec Consulting Ltd., Winnipeg, MB. 123 pp.

Stantec. 2015. Keeyask Generation Project monitoring program Gull Rapids 2014 colonial waterbird summary. Report #14-01. Prepared for Manitoba Hydro by Stantec Consulting Ltd., Winnipeg, MB. 23 pp.

Strahlecker, D. W. 1978. Effect of a new transmission line on wintering prairie raptors. Condor 80: 444–446 pp.

TetrES (TetrES Consultants Inc.). 1996. Water level enhancement study — terrestrial environmental field report 1995. TetrES Consultants Inc., Winnipeg, MB. 199 pp.

TetrES. 1997. Lower Churchill River — water level enhancement study — terrestrial environmental field report 1996. TetrES Consultants Inc., Winnipeg, MB. 293 pp.

TetrES. 1998a. Lower Churchill River — water level enhancement weir project — terrestrial environmental field report 1997. TetrES Consultants Inc., Winnipeg, MB. 109 pp.

TetrES. 1998b. Lower Churchill River — water level enhancement weir project — terrestrial environmental field report 1998. TetrES Consultants Inc., Winnipeg, MB. 45 pp.

TetrES. 2000. Lower Churchill River — water level enhancement weir project — terrestrial environmental field report 1999. TetrES Consultants Inc., Winnipeg, MB. 49 pp.



TetrES. 2003a. Wuskwatim Generating Station avian field studies report, 2000. Nisichawayasihk Cree Nation-Manitoba Hydro Joint Environment Studies Report # 03-17. TetrES Consultants Inc., Winnipeg, MB. 77 pp.



TetrES. 2003b. Wuskwatim Generating Station avian field studies report, 2001/2002. Nisichawayasihk Cree Nation-Manitoba Hydro Joint Environment Studies Report # 03-18. TetrES Consultants Inc., Winnipeg, MB.

TetrES. 2003c. Wuskwatim Generation Project Environmental Impact Statement: Volume 6, Section 8: Birds. Prepared for Manitoba Hydro and Nisichawayasihk Cree Nation. 192 pp.

TetrES. 2004. Wuskwatim Generating Station avian monitoring report, 2004. Nisichawayasihk Cree Nation-Manitoba Hydro Joint Environmental Studies Report # 04-08. TetrES Consultants Inc., Winnipeg, MB.

TetrES. 2005a. Conawapa generation project — avian field studies report 2004. Environmental studies program report # 04-01. TetrES Consultants Inc., Winnipeg, MB. 97 pp.

TetrES. 2006. Conawapa generation project — avian field studies report 2005. Environmental studies program report # 05-01. TetrES Consultants Inc., Winnipeg, MB. 138 pp.

TetrES. 2007. Keeyask Project — avian field studies report 2006. Environmental studies program report # 06-01. Prepared for Manitoba Hydro by TetrES Consultants Inc., Winnipeg, MB. 58 pp.

TetrES. 2008a. Conawapa generation project — avian field studies report 2006. Environmental studies program report # 06-01. TetrES Consultants Inc., Winnipeg, MB. 173 pp.

TetrES. 2008b. Wuskwatim Generation Project terrestrial effects monitoring program avian studies, 2007. Report # 08-01. Prepared for the Wuskwatim Power Limited Partnership by TetrES Consultants Inc., Winnipeg, MB. 124 pp.

TetrES. 2008c. Keeyask Project — avian field studies report 2007. Environmental studies program report # 07-01. A report prepared for Manitoba Hydro by TetrES Consultants Inc., Winnipeg, MB. 50 pp.

TetrES. 2009a. Conawapa generation project — avian 2007 field studies report. Environmental studies program report # 07-02. TetrES Consultants Inc., Winnipeg, MB. 170 pp.

TetrES. 2009b. Wuskwatim Generation Project terrestrial effects monitoring program avian studies, 2009. Report # 09-16. Prepared for the Wuskwatim Power Limited Partnership by TetrES Consultants Inc., Winnipeg, MB. 117 pp.

TetrES. 2010. Conawapa Generation Project — avian 2009 field studies report. Environmental studies program report # TERR-09-01. TetrES Consultants Inc., Winnipeg, MB. 161 pp.

The Town of Churchill and Manitoba Hydro. 1997. Lower Churchill River water level enhancement weir project — environmental impact statement. December 1997. 1138 pp.

Webb, R. 1973. Wildlife resource impact assessment Lake Winnipeg, Churchill and Nelson Rivers hydroelectric projects: No. 1 Outlet Lakes. Lake Winnipeg, Churchill and Nelson Rivers Study Board, Winnipeg, MB. 128 pp.



Webb, R. 1974. Wildlife resource impact assessment Lake Winnipeg, Churchill and Nelson rivers hydroelectric project: No.2 Southern Indian Lake. Lake Winnipeg, Churchill and Nelson Rivers Study Board, Winnipeg, MB. 206 pp.

Webb, R., and Foster, J. 1974. Wildlife resource impact assessment Lake Winnipeg, Churchill and Nelson Rivers hydroelectric projects: No. 3 Lake Winnipeg, Lower Churchill River, Rat-Burntwood Diversion. The Lake Winnipeg, Churchill and Nelson Rivers Study Board, Winnipeg, MB. 263 pp.

Weseloh, D. V. C. 2011. Inland colonial waterbird and marsh bird trends for Canada. Canadian Biodiversity: Ecosystems Status and Trends 2010 Technical Thematic Report No. 18. Canadian Councils of Resource Ministers, Ottawa, ON. 33 pp.

WRCS (Wildlife Resource Consulting Services MB Inc.). 2011. Bipole III transmission project — birds technical report. Wildlife Resource Consulting Services MB Inc., Winnipeg, MB. 596 pp.

WRCS. 2012. Wuskwatim transmission line monitoring program terrestrial monitoring program wildlife final report. Prepared for Plus4 Consulting and Manitoba Hydro by Wildlife Resource Consulting Services MB Inc., Winnipeg, MB. 69 pp.

REGIONAL CUMULATIVE EFFECTS ASSESSMENT – PHASE II LAND – AQUATIC FURBEARERS

DECEMBER 2015 6.6-1

6.6 Aquatic Furbearers

6.6.1 Introduction Aquatic furbearers such as beaver (Castor canadensis) are important to people both economically and culturally. They play a key ecological role and provide habitat for other aquatic-dependent wildlife by contributing to the development and cycle of wetland habitats in forested environments. They are ecosystem engineers and a keystone species that modify drainage regimes by engaging in vegetation cutting and dam-building activities that have long-term effects on landscapes (Naiman et al. 1994). Through their activities, beavers increase both habitat heterogeneity and the richness of herbaceous plants at the landscape level (Wright et al. 2002), specifically the species richness of riparian vegetation (Wright et al. 2002), as well as birds (Aznar and Desroschers 2008) and amphibians (Stevens et al. 2007). Beaver were selected as the indicator for aquatic furbearers, because they are associated with terrestrial and aquatic habitats across the entire Regional Cumulative Effects Assessment (RCEA) Region of Interest (ROI). In addition, though limited, more population information is available for beaver than for other aquatic furbearers.

The RCEA Phase I report provided an overview of available information on aquatic furbearers for the RCEA ROI. The availability of population estimates in the form of active beaver lodge census data for pre- and post-hydroelectric development periods is variable and limited throughout the RCEA ROI. Historically, beaver abundance was monitored during the late 1940s and 1950s by Manitoba Department of Mines and Natural Resources (MDMNR) and reported in annual Conservation Officer Trapline Reports. Comparable census data do not generally exist across the RCEA ROI for the post-hydroelectric development period; however, some comparisons were made possible using beaver lodge surveys conducted for the Wuskwatim Generation and Transmission Projects (Berger and Blouw 2007), and the Keeyask Generation Project (Keeyask Hydropower Limited Partnership [KHLP] 2012). Beavers have been commercially trapped across the RCEA ROI both pre- and post-hydroelectric development and considerable harvest information is available. However, trapping records are not considered to reflect population status, because trapping effort and total catch are a reflection of market value. Publicly available Aboriginal Traditional Knowledge (ATK) reports that contain information on beaver populations per se are limited, though ATK on observed effects of water regulation due to hydroelectric development makes direct links between water regime changes and local beaver populations.

The following sections describe the approach and methods used to evaluate changes in the indicators selected to evaluate the status of beaver within the RCEA ROI at the ecozone and terrestrial region scale for the pre- and post-hydroelectric development periods. Pathways of effects have been identified, and the indicators to assess the effects on beaver described. Assessments of habitat were conducted on both the terrestrial region scale as well as on selected portions of shoreline and riparian habitat on the regulated system to evaluate effects on beaver habitat and populations because of hydroelectric development. Where information was available, local effects have been described based on technical information, local knowledge and ATK.


DECEMBER 2015 6.6-2

6.6.1.1 Pathways of Effects The effects of hydroelectric development on beaver populations at the terrestrial regional and more localized levels have not been extensively studied within the RCEA ROI. Although there is no specific literature on the effects of hydroelectric development on beaver, their habitat is associated with aquatic environments both on-system (i.e., where water regulation occurs) and off-system (i.e., inland lakes and streams). Flooding, water fluctuations and dewatering are potential physical factors that could affect shorelines and riparian areas, resulting in habitat alteration/change (Figure 6.6.1-1). Water regime alterations (flooding and drawdown) can potentially result in increased beaver mortality from freeze-outs and entrance exposure during winter; however, this has not been documented in scientific literature. Fluctuations in water levels can lead to changes to riparian habitats and terrestrial shoreline vegetation species, altering or degrading beaver habitat. Increases in water flow due to water regulation could potentially result in the washing away of feed piles in strong current during fall; however, there is no specific literature or research regarding this issue. Within the terrestrial ecosystem, flooding can also result in habitat changes farther inland, leading to alteration of habitat and possibly the creation of new riparian areas that could be suitable for beaver. Transmission line development can potentially lead to increased access by humans and predators, and thus to higher levels of mortality. Beaver activity may be impacted in developed areas and there can be local impacts to beaver populations in areas of hydroelectric infrastructure and access, as nuisance beavers are often trapped and removed from these areas. Figure 6.6.1-1 illustrates the environmental drivers and stressors (linkages) included in assessing the overall health of beaver as a Regional Study Component (RSC).


DECEMBER 2015 6.6-3

Figure 6.6.1-1: Potential Effects Pathways of Hydroelectric Developments on Beaver


DECEMBER 2015 6.6-4

6.6.1.2 Indicators and Metrics The RCEA Phase I report outlined a number of high-level reviews and assessments that have been carried out on aquatic furbearers throughout the RCEA ROI. Due to a considerable lack of quantitative historical population data on beaver for the RCEA ROI, the metrics and indicators selected are primarily habitat based (Table 6.6.1-1). However, population size can be inferred from beaver lodge densities using the limited data that were available for this study. Where possible, population increases or declines can be assessed from the number of active (e.g., Photo 6.6.1-1) and non-active beaver lodges based on historical census data and limited post-hydroelectric development beaver-lodge survey data, as part of the Wuskwatim and Keeyask Generation and Transmission Projects.

Table 6.6.1-1: Indicators and Metrics for Beaver

Indicator Metric

*Population size 1. Number of beaver lodges

Habitat 1. km2 of primary habitat 2. Length of primary shoreline habitat on the

regulated system

* Post-hydroelectric development beaver lodge census data were only available for the Wuskwatim and Keeyask terrestrial regions, found in the Western and Eastern Boreal Shield ecozones, respectively.

6.6.1.2.1 Response Indicator — Population Size

A wildlife population includes all individuals living in a particular space and a particular time (Krebs 1985). Population size is influenced by survival of individuals, their reproduction and movements in to and out of the area (Dinsmore and Johnson 2012). Population size is also a common indicator of species’ health and is often based on census techniques, where all animals in a population are counted, or through estimation when a complete count cannot be achieved (Dinsmore and Johnson 2012). Beaver census techniques include counting or estimating lodges, dams, slides, food caches and scent mounds as indices of beaver numbers (Hay 1958).

METRIC 1 — NUMBER OF BEAVER LODGES

Beaver censuses have been conducted using various methods and designs, which are not consistent for the pre- and post-hydroelectric development periods. Although beaver lodge counts were regularly recorded by conservation officers in Registered Trapline (RTL) section in the 1950s, similar post-hydroelectric beaver lodge census data are available for only portions of the Wuskwatim and Keeyask terrestrial regions. As such, these data were evaluated as a population indicator in these two terrestrial regions.


DECEMBER 2015 6.6-5

Photo 6.6.1-1: Typical Active Beaver Lodge in the RCEA ROI

6.6.1.2.2 Driver Indicator — Habitat

Habitat is often recognized as one of the main driving factors behind the health and sustainability of wildlife populations. For beaver, there are different habitat requirements based on changing biological and environmental considerations. Beaver are herbivores and require an abundant supply of woody and herbaceous plants (Jenkins and Busher 1979; Clements 1991; Baker and Hill 2003). Deciduous plants and trees are a critical component and a limiting factor in sustaining beavers through the winter (Novak 1998). Beavers manipulate their environment through the construction of dams, lodges and winter food caches that are stockpiled in deep water near the lodge to ensure underwater access to food resources throughout winter (Lancia et al. 1996). Proximity of deciduous forest to lodges and of food caches to the lodge can affect predation risk, which increases with distance, making them susceptible to predators (Baker and Hill 2003). Aspen (Populus sp.) forests provide a high-quality food and dam-building resource for beaver, which prefer stable water levels that can be controlled through their construction of dams. Large rivers and lakes that have fluctuating water levels and large fetch areas are less suitable for beaver (Slough and Sadleir 1977). Shoreline and bank characteristics are also a factor in beaver habitat selection as steep banks profiles in excess of 12% are rarely used (Slough and Sadleir 1977).

Source: Wildlife Resource Consulting Services, 2010


DECEMBER 2015 6.6-6

METRIC: PRIMARY HABITAT

Habitat is the location where a species’ requirement for food, cover and water exists in adequate supply to ensure their existence, and can be characterized by vegetation type, landform and hydrology (Farmer et al. 1982). Habitat requirements differ among species and are variable both spatially and temporally. The ability of an organism to survive and reproduce relates to the available resources that determine habitat quality (Lancia et al. 1996). Measurements of specific habitat attributes can be used to predict habitat quality and availability (Cooperrider 1986). Modeling of habitat also provides opportunities to assess the status of habitat in a given area, and how it has changed through time. In absence of data on population status and demographics, habitat models provide a viable alternative to assess habitat quality (Lancia et al. 1996; Kuhnke and Watkins 1999).

6.6.1.3 Benchmarks There are no established benchmarks in the literature for assessing changes to beaver habitat. Regional habitat modeling for beaver was completed for each of the RCEA terrestrial regions to determine regional habitat availability in km2. In addition, finer scale beaver habitat modeling was completed for the regulated, on-system areas to determine on-system habitat availability, in km where available data exist. All modeling was conducted for both the pre- and post-hydroelectric development periods.

There are no established benchmarks in the literature for assessing changes to beaver populations. For this assessment, post-hydroelectric development population densities are only available for two terrestrial regions; therefore, data for these areas were used to assess relative change in populations due to hydroelectric development.

6.6.1.4 Approach and Methods

POPULATION

Information and data on beaver populations or trends through active lodge census within the RCEA ROI are limited, and not available for most of the region. Beaver lodge numbers (pre- and post-hydroelectric development) were initially considered as a metric for the beaver population indicator for all terrestrial regions. However, it has since been recognized that these data are not available for most of the terrestrial regions in the RCEA ROI. Pre-hydroelectric development beaver census data were available from historical information from MDMNR Conservation Officer Reports. Beaver lodge censuses were conducted on the historic RTLs. Figure 6.6.1-2 illustrates the boundaries of the RTL sections where pre-hydroelectric development beaver-lodge census data are available.

Beaver lodge census data for pre- and post-hydroelectric development are only available for the Wuskwatim Terrestrial Region (Western Boreal Shield Ecozone) and the Keeyask Terrestrial Region (Eastern Boreal Shield Ecozone). Due to the significant differences in data collection techniques and survey area boundaries between pre- and post-hydroelectric development, several key assumptions and extrapolations were required to illustrate possible changes in beaver lodge densities through time. The approach for assessing beaver lodges densities for pre- and post-hydroelectric development in these two terrestrial regions is found in Appendix 6.6B.


DECEMBER 2015 6.6-7

HABITAT

The assessment of hydroelectric development effects on beaver habitat included two scales of assessment. Ecological effects on the habitat used by beaver populations were first assessed on a terrestrial region basis, through regional habitat modeling using relevant terrestrial habitat data produced for the RCEA (Terrestrial Habitat, Chapter 6.3). Regional habitat modeling was done by identifying waterbodies including creeks, rivers, and small lakes, and applying a 200 m buffer to these features. This buffer distance is based on literature regarding beaver habitat availability, as beaver are limited to habitat associated with aquatic environments (Manitoba Wildlife Branch 1994). Modeled beaver habitat found within the 200 m buffer was further classified using model criteria for primary habitat (see Appendix 6.6A for detailed methods for the regional habitat modeling).

The second scale of assessment was an evaluation of on-system beaver habitat, conducted using the shoreline mapping data produced as part of the overall terrestrial habitat assessment (Terrestrial Habitat, Chapter 6.3). These data included both pre-hydroelectric development and existing environment (EE) shoreline and wetland characterization using available aerial photography (both historical and current), and high-resolution satellite imagery for the regulated systems within the RCEA ROI. The shoreline mapping data consisted of 16 fields that contain numerous attributes that describe the physical characteristics of the shoreline and adjacent terrestrial and aquatic habitat. Primary beaver habitat was modeled using these data, and was based on the identification of habitat attributes that best describe high quality components required to complete their life history — including food (hardwood trees and shrubs), and cover (building material for lodges), and shoreline conditions. Although the model does not include any attributes related to the water regime (e.g., degree of drawdown) present within a given hydraulic zone, the final evaluation includes a qualitative review of available water regime data (Water Regime, Chapter 4.3). Information from monitoring or research on the effects of water regulation on beaver persistence is not available, and as such, was not considered in this assessment. Appendix 6.6A outlines the on-system primary beaver habitat modeling methods in detail. The following sections outline the ecozone assessments undertaken for beaver within the RCEA ROI.

6.6.1.5 Data Limitations The principal data limitations for the assessment of beaver in the RCEA ROI include: • On-system (shoreline) habitat data for pre- and post-hydroelectric development are derived from

various sources, scales and resolution. Areas with overlapping shoreline habitat data for both the pre- and post-hydroelectric development period were variable among terrestrial regions.

• Historic and current beaver census data are limited. • Very little published ATK or local knowledge is available for beaver.

As is the case in all long-term assessments (in this case covering more than forty-five years), limitations in available information inevitably place constraints on the analysis possible. Despite these limitations, as outlined above in the Approach and Methods (Section 6.6.1.4), sufficient information exists to provide data for the selected indicators and a reasonably robust assessment of the impacts of hydroelectric development on beaver within the RCEA ROI. The assessments provided below discuss these limitations


DECEMBER 2015 6.6-8

for those terrestrial regions where there was potential for them to substantively alter any conclusions regarding regional cumulative effects.


DECEMBER 2015 6.6-9

Figure 6.6.1-2: Historic RTLs in the Province of Manitoba circa 1950s



6.6.2 Western Boreal Shield Ecozone Human development in the Western Boreal Shield Ecozone began in the early 1900s with the construction of the Hudson Bay Railway line. Interest in mining and prospecting led to increased infrastructure development in the mid-1950s with the development of Thompson in 1958. Most of the increase in footprint area in this ecozone was due to flooding from the Churchill River Diversion (CRD), which began fully operating in 1976. Access roads related to the construction of the Wuskwatim Generation Project were the other substantive contributor. Most of the hydroelectric and non-hydroelectric linear features were concentrated in the northern and southern extents of the ecozone. The last development in the area was the Wuskwatim Generation Project (GP), commissioned in 2012. Forestry activities have also taken place, primarily in the southern extent of this ecozone.

Map 6.6.2-1 outlines the terrestrial regions found within the Western Boreal Shield Ecozone, overlain with the hydraulic zones used in the physical and aquatic environment portions of the RCEA Phase II report.

6.6.2.1 Changes in the Indicators over Time


As described in the RCEA Phase I report, population data for beaver are very limited for the Western Boreal Shield Ecozone. Data acquired from MDMNR officer reports (1940s through 1960s) provided pre-hydroelectric development beaver lodge census data and trend information. The information illustrates that beaver populations rebounded from pre-World War II overharvest with the establishment of the RTL system. Natural Resource Officer Reports indicate periods of “beaver sickness” and fluctuations in some local populations in the 1940s and early 1950s throughout the terrestrial region. High water levels were reported periodically, resulting in lower than average harvest of beaver by trappers in some years.

The resource use reported for the Nelson House trapline areas starting in the 1940s indicated beaver populations were relatively low during that time, but rapidly increased until the early 1950s. Due to the increase in population, trappers were allowed to harvest more than one beaver per lodge in areas with many active lodges. After 1951, beaver populations began to decrease rapidly due to beaver sickness, resulting in poor trapper harvests up until around the mid-1950s (MDMNR 1946, 1950, 1951a, 1952a, 1953, 1954, 1955b, 1956b, 1957c). By 1955, there were minimal reports of beaver sickness and the beaver population started to rebound. Beaver numbers seemed to be stable until the mid-1980s with some exceptions.

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PAINT TERRESTRIAL REGION

Population

Historic census data from MDMNR (1957b) were used to determine approximate beaver lodge densities in the Paint Terrestrial Region, estimated at approximately 0.097 beaver lodges/km2 (see Appendix 6.6B for methods). These census data are from the historic Nelson House RTL section, which encompasses the Paint Terrestrial Region.

Habitat

Regional habitat modeling in the Paint Terrestrial Region for the pre-hydroelectric development period identified 603 km² of primary beaver habitat.

On-system shoreline habitat modeling within the Paint Terrestrial Region was completed for the typed reaches where data were available. From the modeled on-system data, a total of 8 km of the 609 km of mapped shoreline was identified as primary beaver habitat.

WUSKWATIM TERRESTRIAL REGION

Population

Manitoba Department of Mines and Natural Resources Annual Officer Reports from the 1950s provide historic census records for beaver lodges in the Wuskwatim Terrestrial Region. These data were used to assess the abundance of beavers for the pre-hydroelectric development period, estimated at 0.097 lodges/km2.

Habitat

Regional habitat modeling in the Wuskwatim Terrestrial Region for the pre-hydroelectric development period identified 694 km² of primary beaver habitat.

On-system shoreline habitat modeling within the Wuskwatim Terrestrial Region was completed for the typed reaches where data were available. From the modeled on-system data, a total of 2 km of the 344 km of mapped shoreline was identified as primary beaver habitat.

RAT TERRESTRIAL REGION

Population

Based on historic census data from MDMNR (1957b), approximate beaver lodge densities in the Rat Terrestrial Region were estimated at approximately 0.097 beaver lodges/km2. These census data are from the historic Nelson House RTL section, which encompasses the Rat Terrestrial Region.



Habitat

Regional habitat modeling in the Rat Terrestrial Region for the pre-hydroelectric development period identified 546 km² of primary beaver habitat.

On-system shoreline habitat modeling within the Rat Terrestrial Region was completed for the typed reaches where data were available. From the modeled on-system data, a total of 32 km of the 1,231 km of mapped shoreline was identified as primary beaver habitat.

BALDOCK TERRESTRIAL REGION

Population

Using historic census data from the MDMNR (1957b), beaver lodge densities in the Baldock Terrestrial Region for the pre-hydroelectric development period were estimated to be approximately 0.097 beaver lodges/km2 (see Appendix 6.6B for methods). These census data are from the historic Nelson House RTL section, which encompasses the Baldock Terrestrial Region.

Habitat

Regional habitat modeling in the Baldock Terrestrial Region for the pre-hydroelectric development period identified 79 km² of primary beaver habitat.

On-system shoreline habitat modeling within the Baldock Terrestrial Region was completed for the typed reaches where data were available. From the modeled on-system data, a total of 12 km of the 913 km of mapped shoreline was identified as primary beaver habitat.


PAINT TERRESTRIAL REGION

Population

Population data for beaver post-hydroelectric development do not exist for the Paint Terrestrial Region. However, people from Wabowden have commented on the decreased beaver populations along the rivers due to fluctuating water levels. One trapper noted that in 1960 (the first year that Kelsey operated), most beaver were lost and that as of 1990, beaver continued to be affected because they were being frozen out and often starved in the winter (MacKay et al. 1990).

Habitat

Regional habitat modeling identified 601 km² of primary beaver habitat in the Paint Terrestrial Region for the post-hydroelectric development period; therefore, there was a 2 km2 loss of primary beaver habitat at



the regional scale. Appendix 6.6A, Table 6.6A-11 shows the detailed results for the primary habitat modeling. Map 6.6.2-2 shows the results of the pre- and post-hydroelectric development regional beaver habitat modeling.

On-system shoreline habitat modeling for the Paint Terrestrial Region post-hydroelectric development was completed on the typed reaches where data were available. The total change in primary beaver habitat was a loss of three linear km. Appendix 6.6A, Table 6.6A-7 shows the detailed results for the on-system habitat modeling.

WUSKWATIM TERRESTRIAL REGION

Population

Based on a review of all survey information available from ongoing environmental monitoring for the Wuskwatim Generation Project, Table 6.6.2-1 illustrates the range of estimates for beaver densities based on active lodge censuses within the Wuskwatim Terrestrial Region. Surveys included both aerial and boat-based studies in various years, as described in Appendix 6.6B. It should be noted that both the areas surveyed and the methods used were variable over time. The 2007 survey showed beaver densities of 0.15 lodges/km2. This density dropped in 2009, ranging from 0.09 to 0.13 lodges/km2 depending on the methods used to tally active beaver lodges. Beaver lodge densities in 2010 remained approximately the same as 2009, but later climbed in 2011 to 0.17 lodges/km2.

Table 6.6.2-1: Post-hydroelectric Active Beaver Lodge Densities in the Wuskwatim Terrestrial Region

Source Year of Survey Active Lodges

Survey Area (km2)

Beaver Lodge Density (km2)

Paillé and Berger 2010 Spring 2009 Aerial 147 1098 0.13

Paillé and Berger 2010 Fall 2009 Aerial 125 1098 0.11

Berger and Blouw 2007 2007 Boat 68 442 0.15

Johnstone et al. 2010 2009 Boat 41 442 0.09

Kelly et al. 2012 Fall 2010 Aerial 127 1098 0.11

Kelly et al. 2012 Fall 2011 Aerial 189 1098 0.17

Average 0.13

1 Tables, figures and maps with a letter in their number (e.g., A) can be found in the appendices for this chapter.

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Habitat

Regional habitat modeling identified 691 km² of primary beaver habitat in the Wuskwatim Terrestrial Region for the post-hydroelectric development period, resulting in a 3 km2 loss in primary beaver. Map 6.6.2-3 illustrates the results of the regional habitat modeling. Appendix 6.6A, Table 6.6A-1 shows the detailed results for the regional habitat modeling.

On-system shoreline habitat modeling for the Wuskwatim Terrestrial Region post-hydroelectric development was completed on the typed reaches where data were available. The total change in primary beaver habitat was a loss of two linear km. Appendix 6.6A, Table 6.6A-7 shows the detailed results for the on-system habitat modeling.

RAT TERRESTRIAL REGION

Population

Population data for beaver post-hydroelectric development do not exist for the Rat Terrestrial Region. However, the people from Nisichawayasihk Cree Nation who use the Rat Terrestrial Region as traditional hunting and trapping areas indicate a loss of shoreline habitat for beaver has resulted in decreased abundance (Summary of Community Information, Section 3.5.9.4).

Habitat

Regional habitat modeling identified 545 km² of primary beaver habitat in the Rat Terrestrial Region for the post-hydroelectric development period, resulting in a 0.35 km2 loss in primary beaver habitat. Map 6.6.2-4 shows the results of the pre- and post-hydroelectric development beaver regional habitat modeling in the Rat Terrestrial Region. Appendix 6.6A, Table 6.6A-1 shows the detailed results for the regional habitat modeling.

On-system shoreline habitat modeling for the Rat Terrestrial Region post-hydroelectric development was completed on the typed reaches where data were available. The total change in primary beaver habitat was a loss of 27 linear km. Appendix 6.6A, Table 6.6A-7 shows the detailed results for the on-system habitat modeling.

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LakeGoodwin

Rat

PemichigamauLake

Rat

Lake

Apeganau

Lake

Burntwood

Wimapedi

R

Missipisew

LakeNiblockRiver

DionLake

Lindsay Lake

Hargrave

Grass

Rosenberry

Davis

River

R

Lake

WapisuLake

Notigi

OsikL

R

Misinagu

LakeLake

Mynarski

KinwawLake

Lakes

L

Macheewin

Fold

Leftrook

ThreepointLake

Ck

FergussonFiveMile

Lake

Setting

Lake

PakwaL

L

LakeKiski

LakeGormley

Waskik L

ClarkeLake

ConlinLake

Lake

Fish

LakeLake

LakeTullibee

LakeWuskwatim

Lake

Lake

LHarding Tetroe

OdeiLNile

LakeOpegano

Ospwagan

LJoey

River

River

PhillipsLake

Halfway

Scatch

Duck

Lake

River

LakeGreenaway

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Bear

Paint

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L

TreeBirch

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HunterL

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Roe Lake

PAINT LAKEPROVINCIAL

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Map 6.6.2-3

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RatTerrestrial Region

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Takipy

LaurieRiver

LynnLake

Highrock

RuttanMine

Notigi

Evans

McKnight

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Ck

LakeKaykayk

FinchLake

Wasekwan

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BurgeLake

Keewatin

Lake

Cockeram

LakeAnsonLake

Lake

May

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L

Eldon

Chicken

WattL

Elvyn L

Flatrock

River

Lake

LakeTakipy

Guthrie

BattyL

Lake

Lake

Craik

Lake

Burntwood

Lake

Suwannee

Lake

Lake

Lake

Granville

Beaucage

LBridal

SickleLafontaine

LStag

LakeLake

HughesLake

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EagleLake

Hughes

Barrington

Lake

River

LakeAdam

LeafRapids

Eden

Lake

BissettIs

Granville

Costello

Lake

Falls Suwannee

Lake

Nelson

Highrock

Lake

Wheadon

R

Lake

Wimapedi

LakeRiel

Ck

Osborn

DriftwoodParent

River

Apeganau

HallLake

River

LakeGoodwin

Rat

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Karsakuwigamak

River

Lake

River

Lake

MacBride

Opachuanau

McfaddenFraser

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Lake

RustyLake

Lake

LRuttan

Lake

Rat

Lake

Apeganau

Lake

Burntwood

Wimapedi

River

R

Lake

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OsikL

R

Misinagu

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Mynarski

Rat

Issett

L

Is

Lemay

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River

KinwawLake

Lakes

L

Macheewin

Fold

Leftrook

ThreepointLake

Ck

Fergusson

LakeTullibee

LakeWuskwatim

Lake

LivingstonLake

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Sandhill

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BALDOCK TERRESTRIAL REGION

Population

Population data for beaver post-hydroelectric development do not exist for the Baldock Terrestrial Region. However, the Tataskweyak Cree Nation, whose Resource Management Area includes portions of the Baldock Terrestrial Region, indicated that fluctuating water levels, as well as rising water levels in the winter and hanging ice, have decreased the abundance of beaver in the Burntwood River (Split Lake Cree-Manitoba Hydro Joint Studies 1996).

Habitat

Regional habitat modeling identified 78 km² of primary beaver habitat in the Baldock Terrestrial Region for the post-hydroelectric development period resulting in a 0.19 km2 loss in primary beaver. Map 6.6.2-5 shows the results of pre- and post-hydroelectric development modeling in the Baldock Terrestrial Region. Appendix 6.6A, Table 6.6A-1 shows the detailed results for the regional habitat modeling.

On-system shoreline modeling for the Baldock Terrestrial Region post-hydroelectric development was completed on the typed reaches where data were available. The total change in length of primary beaver habitat is a loss of 12 linear km. Appendix 6.6A, Table 6.6A-7 shows the detailed results for the on-system habitat modeling.

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Barrington

Lake

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Opachuanau

Big

Lake

Sand

Lake

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Southern

Indian

Lake

Lakes

BaldockLake

Northern

LakeThorsteinson

Gauer

Lake

Sipiwesk

Lake

Lake

Indian

Lake

Fidler

Lake

LakeWaskaiowaka

Lake

Split

AMISK PARKRESERVE

NUMAYKOOS LAKEPROVINCIAL PARK

SAND LAKESPROVINCIAL

PARK

KelseyG.S.

WuskwatimG.S.

LeafRapids

Thompson

York Factory FirstNation


South Indian Lake

ThicketPortage

(NAC)

Pikwitonei(NAC)

TataskweyakCree Nation


Nelson House (NAC)

Wabowden(NAC)

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LegendPre- and Post-HydroelectricDevelopment Primary Beaver HabitatPrimary Beaver Habitat removed byHydroelectric DevelopmentTerrestrial Region

InfrastructureGenerating Station (Existing)Transmission Line (Existing)Transmission Line (UnderConstruction)RailFirst Nation ReserveRCEA Region of Interest

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INDICATOR RESULTS

Population

Based on the assessment of pre- and post-hydroelectric development information, it was only possible to compare approximate beaver population densities in the Wuskwatim Terrestrial Region. Pre-hydroelectric development beaver densities were found to be 0.097 (0.1) lodges per km² based on the historical accounts by conservation officers in the 1950s. Post-hydroelectric development densities were calculated based on the various field surveys described and averaged 0.13 lodges per km2. As there is no statistical significance associated with these estimates, and in consideration of the limitations of the data for comparison, the information would suggest that there has been little change in beaver populations at the level of the terrestrial region due to hydroelectric and other development. Comparisons for beaver population indicators for the Baldock, Rat, and Paint terrestrial regions are not available.

Habitat

Maps 6.6.2-2 to 6.6.2-5 illustrate the results of the regional habitat modeling undertaken to quantify and map primary beaver habitat pre- and post-hydroelectric development. The total available regional primary beaver habitat in the Western Boreal Shield Ecozone in the period pre-hydroelectric development was estimated at 1,923 km2, with 1,917 km2 of modeled habitat available post-hydroelectric development — a net reduction of 5.85 km2 (or 0.3%). The Paint Terrestrial Region experienced a decrease of 2.08 km2 of primary beaver habitat. The Wuskwatim Terrestrial Region experienced a decrease of 3.23 km2 of primary beaver habitat. The decrease in primary beaver habitat in the Rat Terrestrial Region (0.35 km2) and the Baldock Terrestrial Region (0.19 km2) was minimal. Table 6.6.2-2 summarizes these results.

Table 6.6.2-2: Regional Modeling of Primary Beaver Habitat Pre- and Post-hydroelectric Development in the Western Boreal Shield Ecozone

Terrestrial Region Pre-Hydroelectric Development (km2)

Post-Hydroelectric Development

(km2) Change (km2) Percent

Change (%)

Paint 603.14 601.06 -2.08 -0.34

Wuskwatim 694.94 691.71 -3.23 -0.46

Rat 546.06 545.71 -0.35 -0.06

Baldock 79.13 78.94 -0.19 -0.24

Ecozone Total 1,923.27 1,917.42 -5.85 -0.30



Table 6.6.2-3 illustrates the change in on-system primary beaver habitat between the pre- and post-hydroelectric development periods. The available data suggest a reduction in primary on-system beaver habitat across the ecozone as a whole. However, no total was calculated for the entire ecozone, because data were available for only portions of each terrestrial region.

Table 6.6.2-3: Modeled On-system Primary Beaver Habitat Western Boreal Shield Ecozone

Terrestrial Region Pre-Hydroelectric

Development Shoreline Habitat

(km)

Post-Hydroelectric Development

Shoreline Habitat (km)

Change (km)

Paint 8.79 5.78 -3.01

Wuskwatim 2.94 0.32 -2.62

Rat 32.53 4.98 -27.55

Baldock 12.47 0 -12.47


POPULATION

For a period, beaver populations were very low because of overharvest and disease during the 1940s. Based on harvest information, beaver populations increased during the early 1950s and stabilized with the establishment of the RTL system. Comparison of census data pre- and post-hydroelectric development in the Wuskwatim Terrestrial Region suggests that beaver lodge densities likely did not decline because of hydroelectric development in the Western Boreal Shield Ecozone, and may have increased slightly. However, other factors besides development may have influenced beaver population trends over the same period, such as reduced demand for pelts due to lower prices. It should also be noted that the Wuskwatim Terrestrial Region was not affected by the same degree of flooding as portions of the Paint and Baldock terrestrial regions, and as such may not be representative of the ecozone as a whole.

HABITAT

The majority of flooding caused by the CRD occurred in this ecozone, particularly in Hydraulic Zone 6. The Notigi Control Structure (CS) caused approximately 453 km2 of flooding in the Rat River system (including Issett, Rat and Notigi lakes), and increased water levels by about 15 m just upstream of the control structure. From 1978 to 2014, the average seasonal drawdown was 2.2 m, while the minimum and maximum drawdown was 0.6 m and 3.9 m, respectively. The reach between Notigi CS and Early Morning Rapids was not affected by flooding, but flows have increased above the natural range because of the CRD (Water Regime, Chapter 4.3). There were backwater effects up the Burntwood River to Gate Falls



and up the Footprint River to Osik Lake. It was typical to see higher water levels during winter on Wapisu and Footprint Lakes, which may have benefited beaver by maintaining water levels.

Flooding of Wuskwatim Lake following construction of the Wuskwatim GS was minimal, with 0.5 km2 of additional area being flooded. The last unit of the Wuskwatim GS went into service in 2012. On Wuskwatim Lake, there were minimum levels of operation and less than 0.30 m of variation in open water and winter conditions, which would be favorable for beaver. In Hydraulic Zone 9 (Burntwood River), the CRD causes greater flows, where approximately 52.3 km2 of flooding was recorded, with the highest water levels during winter.

The total available regional primary beaver habitat modeled in the Western Boreal Shield Ecozone pre-hydroelectric development was 1,923 km2, with 1,917 km2 available post-hydroelectric development. The extent of beaver habitat loss at the regional scale resulting from hydroelectric development was minimal — roughly 6 km2 (0.3%) for the whole ecozone. This may be realistic on a regional basis because, though considerable amounts of habitat would no longer be suitable or have been lost, over time other areas of suitable habitat would have developed due to fire or other successional influences.

The on-system shoreline habitat modeling suggests a reduction in primary on-system habitat post-hydroelectric development, likely considerable in two of the four terrestrial regions. The figures suggest the degree of change in each of the terrestrial regions rather than an absolute change, because data were not available for all on-system shoreline areas. On-system flooding would have two potential effects on beaver habitat: inundating previously available beaver habitat, as well as moving shorelines back into previously inland areas, some of which would become suitable habitat for beaver.

Beaver are also affected by the various water regimes in the hydraulic zones assessed, yet not all aspects of the water regime have been possible to accommodate in the beaver habitat model. Flooding was captured, because new, flooded shorelines could be assessed (where data were available) to identify the amount of primary habitat; however, water drawdown or fluctuation is not captured by the figures for modeled on-system beaver habitat. Regional modeled beaver habitat is not affected by these factors. A further explanation of the limitations of the modeled beaver habitat data is provided in Appendix 6.6A.

Webb and Foster (1974) noted that at that time (pre-hydroelectric development) beaver were generally harvested from small streams and creeks peripheral to the Rat and Burntwood rivers, rather than within the rivers themselves, because the flow in these systems was generally too high for beaver to establish their houses. Therefore, despite later effects of the operating regime that would be negative for beaver survival in some mainstem sections of these river systems, in some areas beaver would not have been displaced because earlier conditions had not been conducive to their survival.


Comparing the status of beaver populations in the Western Boreal Shield Ecozone for pre- and post-hydroelectric development is challenging due to lack of quantitative data for the two periods. The comparisons of available census data for the Wuskwatim Terrestrial Region would suggest that beaver lodge densities have remained stable or possibly increased during the period of hydroelectric development. These pre- and post-hydroelectric beaver lodge density estimates are the result of