Assessment of Atlantic Salmon Restoration Efforts in the Credit River

Marc Desjardins and Jim Bowlby Lake Ontario Management Unit

Ontario Ministry of Natural Resources

2

Atlantic Salmon Research and Assessment Group

Strategy: Take a life cycle and habitat approach to identify needs woven into a spatial-temporal framework across the ecosystem.

2-3 years (tribs)

2-3 years (lake)

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Objectives for juvenile Atlantic salmon in the Lake Ontario Atlantic Salmon

Restoration Plan1: • By the fifth year of the program, there will be a density of 0.05-0.5

fingerling/m2 (stocked as Spring Fingerlings) in the stocked streams, measured in late summer or early fall.

• By the fifth year of the program, there will be at least 20 percent survival of

fingerlings to the smolt stage in the stocked streams.

1 Miller-Dodd, L., and S. Orsatti. 1995. An Atlantic salmon restoration plan for Lake Ontario. Ontario Ministry of Natural Resources. Lake Ontario Assessment Internal Report LOA 95.08. Napanee.

An Atlantic Salmon Restoration Plan for Lake Ontario

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Restoration Approach

• Stocking to focus on three best bet streams Credit River, Cobourg Brook, Duffins Creek • Stocking of multiple strains LaHave, Sebago, Lac St. Jean • Stocking of multiple life stages spring fingerling; fall fingerling; spring yearling

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“CSI ATLANTIC SALMON”

• All brood fish in the hatchery are

tagged (PIT tag) and genotyped.

• Families and their progeny can be recognized by their unique genetic makeup.

• Enables us to assess:

• stocking strategies – 3 life stages

• performance of 3 strains

• Tissue samples are collected in the field from adult and juvenile Atlantic salmon.

• Non-lethal sampling method.

PIT TAG

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127,750

44,614

64,883

92,306

37,513

Spring Fingerling

Fall Fingerling

Spring Yearling

Atlantic Salmon Stocking

237,247

92,306

37,513

Totals

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Methods – Fall Parr Sampling

• Started in Credit River in 2008

• First 3 weeks of October

• Capture by electrofishing

• Mark 200-500 parr with Visual Implant Elastomer (VIE) – batch mark

• Recapture following week for population estimates

• Fin tissue collected for DNA to detect wild parr

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By the fifth year of the program, there will be a density of 0.05- 0.5 fingerling/m2

0.0

0.5

1.0

1.5

2.0

2.5

West Credit

Forks Provincial

Park

Forks of Credit Road

Black Creek

Den

sity

(No.

m -2

)

Target density

2010 data

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127,750

44,614

64,883

Spring Fingerling

Numbers Spring Fingerling Stocked

237,247

Totals

10

19,702

5,881

14,535

Atlantic Salmon Fall Population Estimate

40,118

127,750

44,614

64,883

237,247

Totals

Spring Fingerling

11

19,702

5,881

14,535

Atlantic Salmon Fall Population Estimate

40,118

127,750

44,614

64,883

237,247

Totals

Spring Fingerling

Survival Target 0.20

12

19,702

5,881

14,535

Atlantic Salmon Smolt Estimate

40,118

127,750

44,614

64,883

237,247

Totals

Spring Fingerling

Smolt Estimate 8,023 3,940

1,176

2,907

13

0

5

10

15

20

5 7 9 11 13 15 17 19Fork length (cm)

% F

requ

ency West Credit (626)

Black Creek (916)

0

5

10

15

20

5 7 9 11 13 15 17 19Fork length (cm)

% F

requ

ency Forks of Credit Rd (505)

Provincial Park (1537)

Not all sites are equal

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Methods – Spring Out-Migrant Sampling

• Started in Credit River in 2011 • April to mid to late June • Capture by Rotary Screw Trap • Proportion of catch marked with Visual Implant Elastomer (VIE) • Transported upstream 4km • Recaptures used for population

estimates • Fin tissue collected for DNA - assess

stocking strategy - wild fish

15

0

5

10

15

20

25

30Ap

ril 1

April

5

April

9

April

13

April

17

April

21

April

26

April

30

May

4

May

8

May

12

May

16

May

21

May

25

May

29

June

2

June

6

June

10

June

15

June

19

June

23

0

5

10

15

20

25

30

35

40

45

50

Atlantic SalmonDischarge

Dis

char

ge (m

3 /s)

Cat

ch

Out-migrant estimate 5357 (SE 1829) Darroch Estimate

226 Atlantics captured 11 recaptured

9 batch marked ATS recaptured

2011 Data

16

0

1

2

3

4

5

6 Age 2 Age 1

0

5

10

15

20

25 Age 2 Age 1

0123456

Apr

il 5

Apr

il 9

Apr

il 13

Apr

il 17

Apr

il 21

Apr

il 25

Apr

il 29

May

3

May

7

May

11

May

15

May

19

Age 2Age 1

Spring Fingerling

Fall Fingerling

Spring Yearling

Cat

ch

Age 2 Age 1

Age 2 Age 1

Age 2 Age 1

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Summary Information

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Preliminary Conclusions

• Survival to first winter high – good habitat • Survival to out migration needs work – PIT Tags in system 2012 • Encouraged by smolt trap performance • All life stages captured – interesting results • Good test of genetic marking and underlying database • Good tool to test Stocking Strategy (life stage and strain) • Good synergies between both assessments demonstrated

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Credit Valley Conservation Trout Unlimited

OFAH Aurora District MNR

Funding - Canada Ontario Agreement