K.L. Howland, C.P. Gallagher, L. Chavarie, Y. Janjua, M. LeClaire D. Leonard, C. Podemski, D. Simmons, W. Bayha, R.F. Tallman, and W.M. Tonn

Research on Sahtu (Great Bear Lake) fisheries and the aquatic ecosystem:

2000-2015

Jane Baptiste Doug Baton Moise Beyonnie Morris Betsidea Gloria Gaudette Les Harris Bruce Kenny Greg Kenny Hughie Kenny Jonas Kenny Mike Legge Morris Lennie Mike Low George Menacho Morris Modeste Nathan Modeste Melissa Lindsay

Isreal Neyelle Lyle Neyelle Zoya Pawlychyn Aaron Swietzer Clyde Takazo Lucy Ann Takazo Freddie Vital Cameron Yukon Cyre Yukon Tyrone Yukon Charity Yukon Chris Yukon Jean-Guy Chavarie Archie Vital John Betsidea Barbara Yukon

Field Work 2000-2014

BRANSON’S LODGE

Areas fished by lodges

ARCTIC CIRCLE LODGE

KEITH ARM McVICAR ARM (TAH – 1500)

GREAT BEAR LODGE

PLUMMERS GREAT BEAR LAKE LODGE

GREAT BEAR TROPHY LODGE

DELINE (FORT FRANKLIN)

GREY GOOSE LODGE

KEITH ARM

Subsistence use only

DEASE ARM (TAH – 2000)

SMITH ARM (TAH – 2500)

Management zone boundaries

PLUMMER’S GREAT BEAR LAKE LODGE (Original location closed 1968)

1) Fisheries independent monitoring of relative abundance, catch rates and biological indicators of harvested and unharvested large bodied fish species in all areas of GBL

Track changes that may occur with changing harvest levels, development and the environment (cumulative impacts)

Stock assessment - model

sustainable harvest levels

Tirato (Smith Arm)

2006, 2011, 2016 Kwit la

(McTavish Arm) 2004, 2009, 2014

Tugacho (Dease Arm)

2005, 2010, 2015

Sahtu (Great Bear

Lake)

Tirato (Keith Arm)

2000-2007, 2012

Turili McVicar Arm

2003, 2008, 2013

Methods

multi-mesh and large (5 inch) mesh gillnets (for consistency with previous studies)

Sample fish for biological characteristics (length, weight, age, sex, maturity, etc.)

dryfish from sampled fish in remote camps, for community distribution

Collect environmental information: temperature, depth, pH, clarity, weather conditions

Local sampling technicians (2-5) from the community of Deline hired to assist with the field component each year.

otoliths

muscle

gill rakers

gonads pectoral fin

Life-history

Diet

Life-history (fecundity, maturity)

stomach

Diet

Morphology

Genetics + Life-history (age)

stomach

Diet

muscle

Diet

gonads

Biological Sampling for Fish

Weight Length

Area of Great Bear LakeKeith McVicar McTavish Dease Smith

Age

(yea

rs)

0

10

20

30

40

Mean (+1 std) 1984-85 Mean (+1 std) 2000-2006 Mean (+ 1 std) 2007-2011 Mean (+ 1 std) 2012-2016

Trout Mean Age – Lake-wide comparison

Spawner

Resting

Spawner

Resting

Females

Males

Lake Trout Maturity % Spawners in adult component of population: Smith Arm: Female 29%, Male 53% Dease Arm: Female 48%, Male 77% McTavish Arm: Female 18%, Male 52% Keith Arm: Female 30%, Male 55% McVicar Arm: Female 43%, Male 82%

Minimum age at maturity:

Female Male Smith 10 13 Dease 12 12 McTavish 15 14 McVicar 14 13 Keith 16 13

• Annual reporting to SRRB and DRRC, meetings

• Contributions to associated follow-on studies

• Need for formal science review (DFO Regional Advisory Process (RAP) meeting) and publishing through DFO Canadian Science Advisory Secretariat.

• Recommend continued monitoring to allow for detection of change

Lake trout

Harvested stocks (fin clips from lodges): • Lack of differentiation among arms due to low levels of gene flow (12/596 =

first generation migrants), recent colonization and large founding populations

2) Compare genetic relationships among fish from different arms of GBL to determine stock structure as it relates to current management zones within GBL

Harris, L., K. Howland, M. Kowalchuk, R. Bajno, M. Lindsay and E. B. Taylor. 2013. Microsatellite and mtDNA Analysis of Lake Trout, Salvelinus namaycush, From Great Bear Lake, Northwest Territories: impacts of historical and contemporary evolutionary forces on Arctic ecosystems. Ecology and Evolution 3:145-161.

Lake trout

Different morphotypes (assessment samples): • morphotypes of Lake Trout from GBL are genetically differentiated • but…they are still genetically more similar to one another than to outside

populations • colonized GBL from a single glacial refugium – intra-lake divergence

2) Compare genetic relationships among fish from different arms of GBL to determine stock structure as it relates to current management zones within GBL

Harris,L., L. Chavarie, R. Bajno, K. Howland, S. Wiley, W. Tonn, and E. Taylor. 2014. Evolution and origin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in Canada's Great Bear Lake. Heredity (avail. online, accepted July 14, 2014)

Cisco

Different morphotypes (assessment samples): • similar to trout, morphotypes of cisco from GBL are genetically differentiated • morphs within a lake genetically more similar to one another than to outside

populations • similar pattern in lakes across North America • only 2 areas of GBL analysed

2) Compare genetic relationships among fish from different arms of GBL to determine stock structure as it relates to current management zones within GBL

Turgeon, J., S.M. Reid, A. Bourret, T.C. Pratt, K.L. Howland, A.M. Muir, J.D. Reist. Morphological and genetic variation in Cisco (Coregonus artedi) and Shortjaw Cisco (C. zenithicus): Evidence for repeated sympatric origin of Shortjaw Cisco in deep inland lakes. Conservation (submitted)

Further work

• Lake wide analysis of cisco • Analysis of whitefish

2) Compare genetic relationships among fish from different arms of GBL to determine stock structure as it relates to current management zones within GBL

zls

2002

Age (years) 0 5 10 15 20 25 30 35 40 45

Fork

leng

th (m

m)

0

200

400

600

800

1000

1000 mm

600 mm

3) Documentation of morphological variation and ecological roles of major fish species:

Lake Trout Growth

Body Shape

Fin and Body Lengths

Head Shape

3 morphs identified

4th morph: rare; difficult to identify as a distinct cluster, but distinguished using MANOVA

Discrimination Analysis:

N=555 adults UPGMA cluster

88-93% classification success

Chavarie, L., K. Howland and W. Tonn. 2013. An exceptional case study of Lake Trout, Salvelinus namaycush, diversity: the coexistence of multiple shallow-water morphotypes in Great Bear Lake, NT. Transactions of the American Fisheries Society 142:814-823.

ƛ = 0.075 p≤0.01 (81 %)

ƛ = 0.17 p≤0.01 (88 %)

ƛ = 0.24 p≤0.01 (74 %)

DF2

DF1 CV1

ƛ = 0.078 p≤0.01 (73%)

CV2

ƛ = 0.086 p≤0.01 (72 %)

ƛ = 0.094 p≤0.01 (59 %)

Keith

McVicar

McTavish

Dease Smith Significant body shape variation

within a morph across arms

Suggests parallel evolution among arms or several colonization events

Morph 1 Morph 2 Morph 3

Chavarie, L., K. Howland, L. Harris and W.Tonn. 2014. Polymorphism in Lake Trout in Great Bear Lake: intra-lake morphological diversification at two spatial scales. Biological Journal of the Linnaean Society, (avail. online, accepted July 24, 2014)

Sahba forms in shallow water (Tahdǝ gosahba )

Dárélı GoSahba (named for outflow of Great Bear Lake) Sahba that will grow large – scientists identify this type as having a longer head and smaller fins.

Sahba k’áht’a (fin) – scientist identify this type as having a shorter head and intermediary fins.

Sahba k’áht’a Nedǝ *(with long fın) Also lives ın deep water – scientists identify this type as having a deeper caudal peduncle and longer fins

Sahba Yéhkw’ene Hızégǝ* (curved jaw) A newcomer (~20 yrs.) – scientists identify this type by the large lower jaw; it is rare and mostly in one area of Great Bear Lake

Sahba Dek’odze (red) Only seen in the spring and in fall in the shore – not identified as a distinct type by scientists; known as a spawner

*New term developed as cross-cultural tool for dialogue about morphology ; forms known but no Dene name existed

Diet- Fatty acids

Discriminant analysis: λ= 0.031 p≤0.01 DF1

DF2

Morph 2

Morph 4

Morph 1

Juvenile

Morph 3

Significant distinction among morphs, especially Morphs 2 and 4

Some overlap among Morphs 1, 3 and

juveniles

Chavarie, L., K. Howland C. Gallagher and W. Tonn. 2014. Fatty acid signatures and stomach contents of four sympatric Lake Trout: assessment of trophic patterns among morphotypes in Great Bear Lake. Ecology of Freshwater Fish (avail. online, accepted September 17, 2014)

Morph 2

Morph 3

Diet: Stomach contents

Morph 4 Rel

ativ

e in

dex

0

10

20

30

40

50

60

70

80

90

100

Fish Invertebrate Benthic Pelagic Surface

0

10

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90

100

Fish Invertebrate Benthic Pelagic Surface

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Fish Invertebrate Benthic Pelagic Surface

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100

Fish Invertebrate Benthic Pelagic Surface

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90

100

Fish Invertebrate Benthic Pelagic Surface0

10

20

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90

100

Fish Invertebrate Benthic Pelagic Surface

0

10

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100

Fish Invertebrate Benthic Pelagic Surface0

10

20

30

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50

60

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80

90

100

Fish Invertebrate Benthic Pelagic Surface

Morph 1

Morph Age-at-

maturity

(yrs)

Length-at-

maturity

(mm)

Immature

growth rate

Adult

growth rate

(K)

Reproduction

investment

Adult L∞

1 17.4 593.4 22.2 0.030 0.090 740.8

2 20.2 703.7 22.1 0.016 0.048 1371.9

3 18.6 581.7 22.3 0.028 0.086 773.7

4 20.2 640.9 22.0 0.027 0.081 809.6

Trout Life history - Biphasic model: results

Classical life-history trade-off

Comparable to piscivore life-history

Intermediate = Comparable to large benthic morph of Arctic Char?

Intermediate = surprising for the most specialized diet?

Chavarie et al. submitted (Journal of Great Lakes Research)

Morph Age-at-maturity Length-at-maturity Adult L∞

1 17.4 593.4 740.8

2 20.2 703.7 1371.9

3 18.6 581.7 773.7

4 20.2 640.9 809.6

South 7.3 454 647

North 10.4 439 647

Trout Life history - Biphasic model

McDermid et al., 2010 Chavarie et al. submitted (Journal of Great Lakes Research)

• narrower interorbital • longer trunk and dorsal • longer gill rakers • shorter lower arch • shorter caudal peduncle

• wider interorbital •shorter trunk and dorsal •shorter gill rakers • longer lower arch • longer caudal peduncle

• shorter, narrower caudal peduncle* • longer snout • shorter lumbar length • longer pectoral fins* • deeper body*

• longer, wider caudal peduncle • shorter snout • longer lumbar length • shorter pectoral fins • shallower body

DFA Axis 1 (68.7%)

-6 -4 -2 0 2 4 6 8

DFA

Axis

2 (2

7.5%

)

-6

-4

-2

0

2

4

6

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Keith Arm - ShallowKeith Arm - DeepDease Arm - ShallowDease Arm - Deep

92.2% classification success

Wilks' Lambda = .039 Chi-square, p<0.0001

Cisco Morphometric Variation

Cisco diversity in diet

Supported by gut contents, fatty acids, stable isotopes

Shallow (<50 m)

Deep (50-100 m)

Mysis relicta

Copepods

Size at Age

Age

0 2 4 6 8 10 12 14 16 18 20 22 24 26

Stan

dard

leng

th (m

m)

50

100

150

200

250

300

Keith Arm - ShallowKeith Arm - DeepDease Arm - ShallowDease Arm - Deep

Howland, K., C. Gallagher, D. Boguski, L. Chavarie, J. Reist, B. Rosenburg and S. Wiley. 2013. Variation in morphology, life history and ecology of cisco in Great Bear Lake, Northwest Territories, Canada. DFO Can. Sci. Advis. Sec. Res. Doc. 2013/106. v + 40 p. ; M. LeClaire, MSc.

4) Understanding spatial variation in the aquatic ecology of Great Bear Lake:

• Build on existing time series for large-bodied fish

species to address questions regarding stock status & sustainable harvest levels

• Address knowledge gaps regarding the lake

ecosystems & the relationships of different ecosystem components to fisheries production

• Develop baseline from which to assess impacts of

climate change & other anthropogenic drivers on lake ecosystems & harvested fish

Methods - Ecosystem Sampling Design Inshore (0-2 m)

Littoral (3-20 m)

Pelagic-profundal (21-50 m)

Pelagic-profundal (51-100 m)

Pelagic-deep profundal (100-150 m)

Depth Zone

Water quality

Zooplankton (plankton net)

Benthic Inverts (Kick, Ponar grab)

Fish (gill nets)

0-2 m Seine only

3-20 m

21-50 m Lower/ Upper Lower/ Upper

51-100 m Lower/ Mid/ Upper Lower/ Mid/ Upper

100+ m Lower/ Mid/ Upper Lower/ Mid/ Upper

Composition, Abundance, Biomass

Composition, Abundance, Biomass

Composition, Abundance, Biomass, Demographics

Temp, Chla, DO, pH, Tubidity, Conductivity

Community-based monitoring sites

Off shore (60 m depth) temperature array; zooplankton; benthic invertebrates

Nearshore benthic/ terrestrial invertebrates

X Deline

Keith Arm

(Johnson 1975 JFRBC)

Development of thermocline in 2012 -14

Mctavish Arm 23-Jul-2014

Benthic invertebrate abundance Great Bear lake 2012

0

100

200

300

400

500

600

700

800

900

1000

Red (0-2 m) Yellow (3-20 m) Green (21-50 m) Purple (51-100 m) Blue (100+ m)

Num

ber o

f aqu

atic

inve

rtebr

ates

in a

sam

ple

Sampling strata

Kick Net Ponar Grab

Local Fisheries- Traditional Ecological Knowledge Environment, human uses and related stressors

Stressor Great Bear Lk Great Slave Lk Climate change Major/

Change in Ice Free period (almost 3 weeks in 30 years) No direct major impact on fisheries yet

Major, Change in ice condition Habitat disturbance, Fish diseases, Change in migration Subsistence: Negative/dangerous in winter Commercial: Positive, longer season

Water level No Major, impact on catches (change in fishing locations, spawning, migration)

Pollution / Water quality No, Well Controlled Major, Fish diseases & contamination

Mining No now Major, water level change, contamination

Commercial fisheries No Minor, Cullage

Sport fisheries Minor (C&R) Minor, C&R mortality

Tourism No Little, Speed boats, Spawning grounds

Transport No Little, Spill

Janjua et al.

Other highlights: • New and updated information on species distribution patterns

and communities

Surface Mid-water Bottom

Lake Trout McTavish Arm 2014

Further work • Lab analyses in progress: zooplankton, benthic invertebrates, fish

• Examine patterns in distribution, abundance, demographics of fish, invertebrates

o relationship to each other, environmental variables,

o changes over time - historical data, reference approach (CHARS), coring

• Utilize data in ecosystem and population models as it becomes available (update Janjua et al. Aquatic Ecosystem Health & Management 2014, Can. Tec. Rep. Fish. Aquat. Sci., in press)

• Lake trout and cisco studies – ongoing; M.Sc. (M. Leclaire), Post-Doc (L. Chavarie)

• Write up TK workshop results (Y. Janjua and L. Chavarie)

• Years 1 – 3 completed in a 5 year cycle:

o Continue in Dease Arm (summer 2015) o Continue community-based monitoring close to Deline

Thank You! Mahsi Cho! • NWT Cumulative Impacts Monitoring Program • Sahtu Renewable Resources Board • Deline Renewable Resources Council • Deline Lands and Finance Corporation • GNWT Renewable Resources Deline • DFO Hay River, Yellowknife & Inuvik • Polar Continental Shelf Project • Natural Sciences and Engineering Research Council • Canadian Circumpolar Institute • Traditional Knowledge, Deline: Paul Modeste, Douglas Baton, John Tutcho, George

Kenny, Morrıs Modeste, Joseph Blondın, Jr., and Alfred Tanıton; community researchers Michael Neyelle &Mavis Baton

• Field Work 2012: Deline -Darren Kenny, Bobby Modeste, Allison Tatti, Gerald Tutcho, Archie Vitale; DFO Winnipeg - Dave Boguski, Kristin Hynes

• Field Work 2013: Deline –Chris Yukon, Archie Vitale, Allison Tatti, Morris Betsidea, Isodore Betsidea; DFO Winnipeg - Kristen Adair

• Field Work 2014: Deline –Chris Yukon, Archie Vitale, Morris Betsidea, George Menacho, Barbara Yukon ; DFO Winnipeg - Dave Boguski, Michel LeClaire

• Invertebrate analyses: Erica Smith, Lyla Witschi, Michelle Wetton, Sarah Semmler