Status of Coregonines in Lake Huron, 1999

Mark EbenerChippewa/Ottawa Resource Authority

Lloyd MohrUpper Lakes Management Unit, Lake Huron, OMNR

Fish Community Objectives

i) Maintain diversity

ii) Sustainable Annual Harvest = 3.8 million kg

iii) Restore lake herring

iv) Protect rare deepwater ciscoes

Total Coregonid Harvest in Lake Huron 1912 to1999

0

1000

2000

3000

4000

5000

6000

7000

1910 1920 1930 1940 1950 1960 1970 1980 1990

Year

To

tal

Ha

rve

st

(kg

x1

000

)

R. Whitefish

Chub

Herring

L. Whitefish

i) Maintain Diversity

ii) Sustainable Annual Harvest - 3.8 x106 kg

Fish Community Objectives

Total Coregonid Harvest in Lake Huron 1912 to1999

0

1000

2000

3000

4000

5000

6000

7000

1910 1920 1930 1940 1950 1960 1970 1980 1990

Year

To

tal H

arve

st (

kg x

1000

) R. Whitefish

Chub

Herring

L. WhitefishFCO

iii) Restore Lake Herring

Total Harvest of Lake Herring in Lake Huron

0

500

1000

1500

2000

2500

3000

3500

4000

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Year

Ha

rve

st

(kg

)

U.S. HURON GEO BAY N.CHAN

% Coregonine Harvest

1912 = 69%

1930 = 18%

1970 = 1%

1999 = 0.4%

1999 Harvest = 15,000 kg

iv) Protect Rare Deepwater Ciscoes

Extinct

Extinct

Extinct

Extinct

Extinct ?

Abundant

Lake Whitefish - Historical development of the fishery

Spangler and Peters (1995):

Native people harvesting whitefish 2,500 B.C.

European settlers harvesting whitefish by 1760

Commercial fishing began in earnst about 1820• Canadian seine fishery for whitefish along Fishing Islands

• gill nets fished near Alpena about 1835

Peak whitefish harvest about 1890• mesh sizes declining from 5-6 inch stretch to 4 1/2 inch

Lake Whitefish - present day commercial harvests

1999 harvest = 4.1 million kg

0

500

1000

1500

2000

2500

3000

3500

4000

4500

5000

1970 1975 1980 1985 1990 1995 2000

Har

vest

(kg

x 1

000)

North Channel

Georgian Bay

Canadian main basin

U. S. waters

Lake Whitefish - Great Lakes Harvest, 1867-1999

1867 1887 1907 1927 1947 1967 198702468

101214

St. ClairOntario

Erie

SuperiorHuron

Michigan

Lake Whitefish - Stock Identification

U. S. waters 8 stocks

8 stocks modeled Canada

Stocks under review in Canada

WFH-01

4-4

4-5

5-8

6-1

Lake Whitefish - Abundance, i.e. Trap net CPUE

0

100

200

300

400

500

600

700

1976 1981 1986 1991 1996

Kil

og

ram

per

Lif

t

U. S waters

Canadian waters

Lake Whitefish - Recruitment

1973 1978 1983 1988 1993 19980

10

20

30

40

50

4-4

5-8

WFH-01

4-5

Good to Excellent - 1977 1986-1991 1998-1999

Fair to Poor - 1983-1985 1992-1995

Lake Whitefish - Growth Changes OH-4/5

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1975 1980 1985 1990 1995

Wei

gh

t in

Gra

ms

10

7

5

3

Mean weight @ age

Lake Whitefish - Growth Changes MH-1

0

500

1000

1500

2000

2500

3000

3500

4000

4500

1975 1980 1985 1990 1995

Weig

ht

in G

ram

s

10+

7

5

3

Lake Whitefish - Condition Changes MH-1

1982 1984 1986 1988 1990 1992 1994 1996 1998

Year

0.5

0.7

0.9

1.1

1.3

1.5

1.7

1.9

Wei

ght

in K

ilogr

am

s

540 mm

500 mm

460 mm

Mean Weight @ Length

Lake Whitefish - Maturity Canadian Waters 1989

0.00

0.20

0.40

0.60

0.80

1.00

1 2 3 4 5 6 7 8 9 10

Pro

po

rtio

n M

atu

re F

em

ale

s

OH1

OH4/5

GB4

50% Maturity

Lake Whitefish - Maturity Canadian Waters 1999

0.00

0.20

0.40

0.60

0.80

1.00

1 2 3 4 5 6 7 8 9 10

Pro

po

rtio

n M

atu

re F

em

ale

s OH1

OH4/5

GB4

50% maturity

Lake Whitefish - Total Mortality Age 5

0.000

0.200

0.400

0.600

0.800

1.000

1976 1981 1986 1991 1996

Inst

anta

neou

s M

orta

lity

Rat

e

WFH-016-1

4-2

Lake Whitefish - Total Mortality Age 9

0.000

0.200

0.400

0.600

0.800

1.000

1.200

1976 1981 1986 1991 1996

Inst

anta

neo

us

Tot

al M

orta

lity

WFH-01

6-14-3

Lake Whitefish - Synopsis

Harvest targeted at lake whitefish - not normal

Abundance peaked in mid 1990’s

Strong year classes 1986 to 1991

Growth slowed significantly in past several years

Condition declining

Maturation has been curtailed

Mortality decreasing over several years

Lake Herring - Current Harvest 1957-1999

Total Harvest of Lake Herring in Lake Huron1957 to 1999 (post collapse)

0

5

10

15

20

25

30

35

40

45

50

1957 1967 1977 1987 1997

Year

Ha

rve

st

(kg

x1

00

0)

U.S. HURON GEO BAY N.CHAN

North ChannelGeorgian Bay

Canadian main basinU.S. main basin

Lake Herring - Stable/Increasing Populations

SevernSound

NE Georgian Bay

Fraser BayNorth Channel

St. Mary’s River

Northshore

Lake Herring - Recruitment Drummond Island Refuge

Lake Herring Relative Abundance in Drummond Island Refuge

0

10

20

30

40

50

60

70

80

90

1979 1982 1985 1988 1991 1994Yearclass

CP

UE

Lake Herring - Synopsis

Little or no information

Historical Saginaw Bay harvest non existent

Strong year class 1994

Increasing abundance in northern regions

Re-newed exploitation interests

Deepwater Cisco - Commercial Harvest 1900-1999

Total Harvest of Deepwater Chub in Lake Huron, 1900 to 1999

0

500

1000

1500

2000

2500

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Year

Ha

rve

st

(kg

x1

00

0)

N.CHAN

GEO BAY

HURON

U.S.

North ChannelGeorgian BayCanadian main basinU. S. main basin

1999 Harvest = 330,000 kg

Deepwater Cisco - Recruitment Canadian Units

1976 1981 1986 1991 19960

10

20

30

40

50

60

5-8

4-5

4-4

Year class

Inconsistent among units

1988 excellent all units

1991-1996 poor main basin

Increasing Georgian Bay

Deepwater Cisco - Condition MH-1

0

50

100

150

200

250

300

1991 1992 1993 1994 1995 1996 1997 1998 1999

Ro

un

d w

eig

ht

(gra

ms)

250

270

290

310

Deepwater Cisco - Stress to Population

Water Belly Syndrome 1998 & 1999 ranged 0-11%

High Incidence of Parasites acanthocephalan worms 40-83% of fish swimbladder nematode 20-92% of fish

Presence of “BKD” 27% of fish Feb. 1998 0% 1999

Deepwater Cisco - Abundance Canada - comml fishery

Chub Relative Abundance

0

50

100

150

200

250

1981 1983 1985 1987 1989 1991 1993 1995 1997 1999

Year

CP

UE

(k

g/1

00

0m

ne

t) OH1

OH3

OH4/5

GB4

Deepwater Chub - Synopsis

Harvest typical of historic

Saginaw Bay replaced by Georgian Bay

Strong year classes in 1988-1990

Decreasing abundance in all regions

Decreasing condition

“Water belly condition” prevalent

Concerns regarding above plus other diseases/parasites

Round Whitefish - Commercial Harvest 1900-1999

Total Harvest of Round Whitefish inLake Huron, 1900 to 1999

0

10

20

30

40

50

60

70

80

1900 1910 1920 1930 1940 1950 1960 1970 1980 1990 2000

Year

Har

vest

(kg)

U.S. HURON GEO BAY N.CHAN

U. S. main basinCanadian main basinGeorgian BayNorth Channel

Round Whitefish - Synopsis

Populations are Stable

Underexploited

Little Knowledge of Populations

Coregonine Summary - FCO Objectives

Diversity objective - met for 3 of 4 species not being met for lake herring

Harvest objective - being exceeded chub about right whitefish too much of total round whitefish about right

lake herring too little Lake herring objective - not being met in Saginaw Bay Deepwater Cisco objective - not being met, probably can’t