Importance of Protecting Lake Trout. 250,000 lakes in Ontario 1% of these contain lake trout Central/eastern Ontario has >1/3 of lakes Provincial responsibility.

Importance of ProtectingImportance of Protecting Lake Trout Lake Trout

•250,000 lakes in Ontario•1% of these contain lake trout•Central/eastern Ontario has >1/3 of lakes• Provincial responsibility to preserve

Why Protect Lake Trout Waters?

Why Protect Lake Trout Waters?Why Protect Lake Trout Waters?

Represents 20-25% of Represents 20-25% of worldworld’s supply’s supply

Largest area of lake Largest area of lake trout waters trout waters

Ontario has greatest Ontario has greatest responsibility in worldresponsibility in world

Lake Trout requirementsLake Trout requirements

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Phosphorous Affects OxygenPhosphorous Affects Oxygen

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Lake Trout Lake ProtectionLake Trout Lake Protection

Province is committed to protecting Province is committed to protecting fish habitatfish habitat

Cooperative effort with Cooperative effort with municipalitiesmunicipalities

Provincial Policy StatementProvincial Policy Statement Official Plan is the planning toolOfficial Plan is the planning tool

Why Protect Lake Trout?Why Protect Lake Trout?

Native only to North Native only to North AmericaAmerica

Native stocks found on Native stocks found on Canadian ShieldCanadian Shield

Isolated 10,000 years agoIsolated 10,000 years ago Lake trout stocks Lake trout stocks

genetically dissimilargenetically dissimilar Once lost, no way to Once lost, no way to

replace itreplace it Keystone species, Keystone species,

indicator of ecosystem indicator of ecosystem healthhealth

Lake Trout Life HistoryLake Trout Life History

Need deep, well Need deep, well oxygenated, cold water oxygenated, cold water lake environments to lake environments to thrivethrive– Late summer criticalLate summer critical

Slow growing, late Slow growing, late maturing, low maturing, low productive potentialproductive potential

Lake Trout vs WalleyeLake Trout vs Walleyelake trout walleye

• Fall spawn, 3-5 month incubation• Females mature @ age-6 to 7 • Produce 900 -2600 eggs per kg• 26 cm fish approx. age-4• Preferred water temperature: 9 -13C

• Spring spawn, 12-18 day incubation• Females mature @ age-3 to 4• Produce 6000 – 7500 eggs per kg• 26 cm fish approx. age-1• Preferred water temperature: 19-23C

Human StressorsHuman Stressors

Mean Volume Weighted Mean Volume Weighted Hypolimnetic Dissolved Oxygen Hypolimnetic Dissolved Oxygen

(MVWHDO)(MVWHDO) Criterion developed by Dr. David Evans in 1993Criterion developed by Dr. David Evans in 1993 Activity levels of lake trout limited by Activity levels of lake trout limited by

concentration of oxygen in waterconcentration of oxygen in water– Reduced oxygen affects swimming ability, feeding, Reduced oxygen affects swimming ability, feeding,

avoidance of predators, growth and survivalavoidance of predators, growth and survival– Juveniles more sensitiveJuveniles more sensitive

At temperatures of 4-14C, oxygen concentrations of 4.4, 5.8 At temperatures of 4-14C, oxygen concentrations of 4.4, 5.8 and 7.1 mg/L limit activity to ¼, ½ and ¾, respectivelyand 7.1 mg/L limit activity to ¼, ½ and ¾, respectively

7 mg/L provide for most daily life support activities7 mg/L provide for most daily life support activities

Additional Supportive DataAdditional Supportive Data

Independent surveys of lake trout Independent surveys of lake trout populations in southern Ontario:populations in southern Ontario:– Lake trout populations good to excellent when Lake trout populations good to excellent when

MVWHDO 7-8 mg/LMVWHDO 7-8 mg/L– Recruitment average to poor when MVWHDO < Recruitment average to poor when MVWHDO <

6 mg/L6 mg/L

The Lake Trout PolicyThe Lake Trout Policy Policy proposal using MVWHDO (7.0 mg/L) Policy proposal using MVWHDO (7.0 mg/L)

posted on Environmental Bill of Rights Registry posted on Environmental Bill of Rights Registry (EBR) for public comment in early 2006(EBR) for public comment in early 2006

EBR decision notice posted May 29, 2006EBR decision notice posted May 29, 2006 Lake trout lakes listed in ‘Inland Ontario Lakes Lake trout lakes listed in ‘Inland Ontario Lakes

Designated for Lake Trout Management’ Designated for Lake Trout Management’ available at: available at: www.mnr.gov.on.ca/mnr/ebr/lake_trout/index.htmlwww.mnr.gov.on.ca/mnr/ebr/lake_trout/index.html

Revisions will require posting on EBR Registry for Revisions will require posting on EBR Registry for public commentpublic comment

Policy implemented Province-widePolicy implemented Province-wide

Historical MVWHDO For Buck LakeHistorical MVWHDO For Buck Lake

Recommended concentration of 7 mg/LRecommended concentration of 7 mg/L

South BasinSouth Basin Sept. 19, 1978 – 7.87 mg/LSept. 19, 1978 – 7.87 mg/L Sept. 01, 1987 – 5.27 mg/LSept. 01, 1987 – 5.27 mg/L Sept. 06, 2007 – 5.91 mg/LSept. 06, 2007 – 5.91 mg/L

North BasinNorth Basin Sept. 06, 2007 – 4.75 mg/LSept. 06, 2007 – 4.75 mg/L

Buck Lake Stocking HistoryBuck Lake Stocking History

three walleye stocking episodes between three walleye stocking episodes between 1935 & 1948 (100,000 to 250,000)1935 & 1948 (100,000 to 250,000)

11 smallmouth bass stocking episodes 11 smallmouth bass stocking episodes between 1935 & 1956between 1935 & 1956

11stst record of lake trout stocking in 1949 with record of lake trout stocking in 1949 with stocking each year between 1959 & 1989, stocking each year between 1959 & 1989, average 4,000 annuallyaverage 4,000 annually

6,000 genetically marked lake trout stocked 6,000 genetically marked lake trout stocked in 1991 & 1992in 1991 & 1992

Historical Fish AssessmentHistorical Fish AssessmentHoop nets

Aug 9-11, 1954

2

21

10

71

77

14

5

24

0 20 40 60 80 100

npike

lmbass

yperch

pumpk

bgill

bcrap

rbass

bhead

Gill nets

16

30

4

6

8

17

7

14

83

165

38

0 40 80 120 160 200

ltrout

cisco

npike

wall

yperch

lmbas

smbas

bcrap

pumpk

bgill

rbas

1972

1960

1959

1992 Buck Lake SLIN Catch 1992 Buck Lake SLIN Catch (total no. fish)(total no. fish)

45

9

0 50 100 150 200 250

lktrout

splake

cisco

npike

smbas

comshin

pumseed

bgill

bcrap

yperch

north (28 sets)

south (75 sets)

1992 Buck Lake SLIN1992 Buck Lake SLIN

0.6 lake trout per net0.6 lake trout per net 32 clipped lake trout (70%)32 clipped lake trout (70%) Mean total length: 39.7 cm (15.6 in)Mean total length: 39.7 cm (15.6 in) Mean fork length: 35.8 cm (14.1 in)Mean fork length: 35.8 cm (14.1 in) Mean weight: 553 gms (1.2 lbs)Mean weight: 553 gms (1.2 lbs)

1997 Buck Lake SLIN 1997 Buck Lake SLIN

1997, Spring Littoral Index Netting (SLIN)1997, Spring Littoral Index Netting (SLIN)– Short sets (30 minutes), small mesh (1.5”,2.0” and 2.5”)Short sets (30 minutes), small mesh (1.5”,2.0” and 2.5”)– Spring, ice out until surface temperature reaches 13CSpring, ice out until surface temperature reaches 13C

May 6-23May 6-23

– Set 59 nets at randomly selected sitesSet 59 nets at randomly selected sites

1997 Buck Lake SLIN1997 Buck Lake SLIN

26

31

4

13

0

5

10

15

20

25

30

35

ltrout cisco npike yperch

0.44 lake trout per net0.44 lake trout per net 17 clipped (65%)17 clipped (65%) Mean age: 6.6 yrsMean age: 6.6 yrs Mean total length: Mean total length:

44.3cm (17.4 in)44.3cm (17.4 in) Mean fork length : Mean fork length :

40.9cm (16.1 in)40.9cm (16.1 in) Mean weight: 875 gms Mean weight: 875 gms

(1.9 lbs)(1.9 lbs)

1997 Buck Lake SLIN –1997 Buck Lake SLIN –lake trout age at sizelake trout age at size

2

3

4

5

6

7

8

9

10

11

200 250 300 350 400 450 500 550 600 650 700 750 800

total length (mm)

ag

e (

yrs)

Summer Profundal Index Netting Summer Profundal Index Netting (SPIN)(SPIN)

Season: mid-July to mid-SeptemberSeason: mid-July to mid-September– Before thermocline collapsesBefore thermocline collapses

Set duration: 2 hoursSet duration: 2 hours Net length: 64 m (210 ft) with 8 mesh sizesNet length: 64 m (210 ft) with 8 mesh sizes Depth ranges: 10-20 m; 20-30m; 30-40mDepth ranges: 10-20 m; 20-30m; 30-40m > 3 mg/L dissolved oxygen> 3 mg/L dissolved oxygen

SPIN ObjectivesSPIN Objectives

1.1. Obtain point-in-time estimate of relative Obtain point-in-time estimate of relative area weighted density of lake trout area weighted density of lake trout (>300mm)(>300mm)

2.2. Obtain representative sample of lake trout Obtain representative sample of lake trout population for diagnostic assessment of population for diagnostic assessment of biological integrity biological integrity

2007 Buck Lake SPIN2007 Buck Lake SPIN 39 net sets, 365 ha 39 net sets, 365 ha

sampled (682 ha total)sampled (682 ha total) Total 41 lake trout caught Total 41 lake trout caught

>300 mm>300 mm Estimated density of 3.4 Estimated density of 3.4

lake trout >300 mm per halake trout >300 mm per ha Population estimate of Population estimate of

1,233 lake trout1,233 lake trout Confidence limits: 465 to Confidence limits: 465 to

2,021 lake trout (68% 2,021 lake trout (68% predicted level)predicted level)

Mean length total catch: Mean length total catch: 35.4 cm (13.9 in) 35.4 cm (13.9 in)

2007 Buck Lake SPIN – 2007 Buck Lake SPIN – Lake Trout LengthsLake Trout Lengths

0

5

10

15

20

25

30

% o

f to

tal

catc

h

25 30 35 40 45 50 55 60 65

Fork length (cm)

Buck vs Loughborough Lake SPINSBuck vs Loughborough Lake SPINS

BuckBuck LoughboroughLoughborough

No. net setsNo. net sets 3939 2828

Total catch LTTotal catch LT 4141 2424

Est. density LTEst. density LT 3.43.4 3.63.6

Conf. limitsConf. limits 465 – 2,021465 – 2,021 0 – 3,2370 – 3,237

Mean length Mean length 35.4 cm35.4 cm 40.8 cm40.8 cm

What can Buck Lake Landowners What can Buck Lake Landowners Do?Do?

1.1. Work with municipality (Official Plan) & Work with municipality (Official Plan) & fellow land owners to support protection & fellow land owners to support protection & enhancement of lake trout habitatenhancement of lake trout habitat

2.2. Work with fellow land owners to reduce Work with fellow land owners to reduce nutrient inputsnutrient inputs

3.3. Water level manipulation?Water level manipulation?

4.4. Creel survey – what’s coming out?Creel survey – what’s coming out?

5.5. Assessment of other fish species?Assessment of other fish species?

Perfect ending to a day on the lakePerfect ending to a day on the lake