[PPT] - Research on Sahtu (Great Bear Lake) fisheries and the aquatic PowerPoint Presentation

SLIDE 1

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

SLIDE 2

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

SLIDE 3

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)

SLIDE 4

1) Fisheries independent monitoring

f 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

SLIDE 5

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

SLIDE 6

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.

SLIDE 7

toliths

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

SLIDE 8

Area of Great Bear Lake

Keith McVicar McTavish Dease Smith

Age (years)

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

SLIDE 9

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

SLIDE 10

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

SLIDE 11

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.

SLIDE 12

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

rigin of sympatric shallow-water morphotypes of Lake Trout, Salvelinus namaycush, in

Canada's Great Bear Lake. Heredity (avail. online, accepted July 14, 2014)

SLIDE 13

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
nly 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)

SLIDE 14

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

SLIDE 15

zls

2002

Age (years)

5 10 15 20 25 30 35 40 45

Fork length (mm)

200 400 600 800 1000

1000 mm 600 mm

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

SLIDE 16

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.

SLIDE 17

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)

SLIDE 18

Sahba forms in shallow water (Tahdǝ gosahbá )

Dárélı̨ GoSahbá (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 Nedǝ́ *(with long fın) Also lives ın

deep water – scientists identify this type as having a deeper caudal peduncle and longer fins

Sahba Yéhkw’e̩nę́ Hı ̨ zégǝ* (curved jaw) A

newcomer (~20 yrs.) – scientists identify this type by the large lower jaw; it is rare and mostly in one area

f Great Bear Lake

S̨ahba 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

SLIDE 19

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)

SLIDE 20

Morph 2 Morph 3