Post on 28-Apr-2017
transcript
FISHERIES MANAGEMENT……………………..….. we make fishing better
The Lake Michigan Fishery:
Current Challenges and Future
Hopes
Bradley Eggold
Fisheries Supervisor
Wisconsin DNR
FISHERIES MANAGEMENT……………………..….. we make fishing better
Outline
• Lake Michigan Ecosystem
• Impacts of Aquatic invasive species
• Current status of food producers
• Chinook salmon Natural Reproduction
• Lake Whitefish
• Lake Sturgeon
FISHERIES MANAGEMENT……………………..….. we make fishing better
1/5 OF THE
WORLD’S
AVAILABLE
FRESH WATER
RELATIVELY
SMALL
WATERSHED
FISHERIES MANAGEMENT……………………..….. we make fishing better
NATURAL
BARRIER
FISHERIES MANAGEMENT……………………..….. we make fishing better
BALANCED NATIVE FISH POPULATION
TOP PREDATORS:
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
NEARSHORE
FISH
COMMUNITY
FISHERIES MANAGEMENT……………………..….. we make fishing better
Native
Invertebrates
FISHERIES MANAGEMENT……………………..….. we make fishing better
NATURAL
BARRIER
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
1830’s
1919
1921
1937
1938
1934
1936
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
1950’s
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
1931
1933
1949
1953
FISHERIES MANAGEMENT……………………..….. we make fishing better
By 1967 up to 85% of the Lake
Michigan fishery biomass was
tied up in alewife flesh
FISHERIES MANAGEMENT……………………..….. we make fishing better
Year
1970 1980 1990 2000 2010
Lo
w
Hig
h
Great Lakes Water
Quality Agreement
Fish biomass
total
phosphorus
round goby
spiny water
flea
zebra mussel
Sea lamprey control;
salmon stocking
quagga mussel
FISHERIES MANAGEMENT……………………..….. we make fishing better
Daphnia
Bosmina
Cyclopoid copepod
Diaptomid copepod
Limnocalanus
Cladocerans Copepods
FISHERIES MANAGEMENT……………………..….. we make fishing better
Crustacean Zooplankton 1998-2011
1998
1999
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011
Bio
ma
ss (
mg
/m3)
20
40
60 Limnocalanus
Calanoids
Cyclopoids
Predatory cladocerans
Daphnia
Non-dahnid cladocerans
Increasing
Decreasing
FISHERIES MANAGEMENT……………………..….. we make fishing better
Daphnia
Bosmina
Cyclopoid copepod
Diaptomid copepod
Limnocalanus
Cladocerans Copepods
But too deep
and too large for
some to eat
1973 1978 1983 1988 1993 1998 2003 2008 2013
Year
0
40
80
120
160
200
240
280
320
360
400
Lak
e-w
ide
biom
ass
(kt) Bl oat er
Sl i m y scul pi n
Deepwat er s cul pi n
Rai nbow s m el t
Round goby
Ni nespi ne s t i ckl eback
Al ewi f e
Slimy sculpin0.32 kt
Bloater1.61 kt
Ninespine stickleback0.004 kt
Round goby10.81 kt
Alewife28.99 kt
Deepwater sculpin1.32 kt
Rainbow smelt0.22 kt
2013 prey fish
composition
Prey fish composition
FISHERIES MANAGEMENT……………………..….. we make fishing better
1967
Chinook Salmon
FISHERIES MANAGEMENT……………………..….. we make fishing better
Strawberry Creek
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
Chinook Natural Reproduction:
Coded Wire Tag vs. Oxytetracycline
OTC
Mark
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
Lake Whitefish Re-colonization in
Wisconsin Tributaries of Green Bay
FISHERIES MANAGEMENT……………………..….. we make fishing better
Menominee River
• In the mid-1800s large runs of whitefish and herring occurred in the Menominee River
• However, precipitous declines were measured by the late 1800s and were attributed to overfishing and habitat degradation from sawmills – whitefish extirpated
Wells and McLain, 1973
FISHERIES MANAGEMENT……………………..….. we make fishing better
Early Signs of Recovery
0
10
20
30
40
50
60
1992 1993 1994 1995
MALES
FEMALES
4
1
32
1
54
4
FISHERIES MANAGEMENT……………………..….. we make fishing better
Age Class Distribution
FISHERIES MANAGEMENT……………………..….. we make fishing better
Recruitment
FISHERIES MANAGEMENT……………………..….. we make fishing better
• Green Bay-wide CPE
deep sites
• Site closest to mouth of
Menominee River
FISHERIES MANAGEMENT……………………..….. we make fishing better
Whitefish Movement
FISHERIES MANAGEMENT……………………..….. we make fishing better
Green Bay Whitefish Sport Harvest
Photo:Alexander’s Sport Fishing
Poor Ice
FISHERIES MANAGEMENT……………………..….. we make fishing better
Lake Michigan / Green Bay Whitefish
Harvest and Quota
FISHERIES MANAGEMENT……………………..….. we make fishing better
Using a Streamside Rearing Facility
on the Milwaukee River for Lake Sturgeon Rehabilitation
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
Streamside Rearing Facility
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
Number of Lake Sturgeon stocked
in the Milwaukee River, 2003 - 2013
Year
2000 2002 2004 2006 2008 2010 2012 2014
Num
be
r S
tocke
d
0
500
1000
1500
2000
2500
Fall Fingerlings
Spring Yearlings
Adult transfer
Streamside Rearing FacilityWild Rose
Fish Hatchery
FISHERIES MANAGEMENT……………………..….. we make fishing better
Milwaukee River
Lake Sturgeon Recoveries
FISHERIES MANAGEMENT……………………..….. we make fishing better
Spring 2013 – Spring Electrofishing surveys
April 22, 2013 – 2 sturgeon, 47.75 and 49.5, RV Finclip
April 25, 2013 – 2 sturgeon, 41.5 RV Finclip and 55” male with
PIT tag.
FISHERIES MANAGEMENT……………………..….. we make fishing better
Summer 2013 – Lake Sturgeon Assessment
FISHERIES MANAGEMENT……………………..….. we make fishing better
Summer 2013 – Lake Sturgeon Assessment
Stocking date of 10/02/2010, length at stocking 215mm, weight
41.3 grams. Length at capture 557 mm and weight 950 grams
FISHERIES MANAGEMENT……………………..….. we make fishing better
Summer 2013 – Lake Sturgeon Assessment
Caught 5 more sturgeon. One sturgeon was from 2011, two
sturgeons from 2010 and one sturgeon from 2009 stockings out
of the Milwaukee River SRF. The fifth sturgeon did not contain
any PIT but was fin clipped with a RV clip.
FISHERIES MANAGEMENT……………………..….. we make fishing better
Summer 2013 – Lake Sturgeon Assessment
A total of 11 lake sturgeon were
caught during this assessment
• 1 from 2009 MIL SRF stocking
• 5 from 2010 MIL SRF stocking
• 3 from 2011 MIL SRF stocking
• 1 recapture
• 1 with RV finclip – MIL SRF
FISHERIES MANAGEMENT……………………..….. we make fishing better
Summer 2013 – Lake Sturgeon Assessment
1) Lake Sturgeon raised in the MIL SRF
seem to be surviving and some are staying in
the area - maybe as a juvenile nursery area.
2) We are getting pretty good growth on
these fish, about 5 inches per year
3) Both PIT tags and finclips are holding
through age 4
4) Survival from upstream stocking (River
Mile 20) does not seem to be an issue
FISHERIES MANAGEMENT……………………..….. we make fishing better
FISHERIES MANAGEMENT……………………..….. we make fishing better
QUESTIONS