Michigan Fisheries: The Big Picture Presented by: Brian Gunderman Date: November 8, 2011.
-
Upload
alyson-kathlyn-marshall -
Category
Documents
-
view
212 -
download
0
Transcript of Michigan Fisheries: The Big Picture Presented by: Brian Gunderman Date: November 8, 2011.
Michigan Fisheries:The Big Picture
Presented by: Brian GundermanDate: November 8, 2011
Fisheries ManagementFisheries Management
• Stocking - restore populations (sturgeon) - create fishing opportunities
lack of spawning habitat - adjust predator:prey ratios
• Regulations - prevent overexploitation - prevent spread of undesirable species - enforce principles of fair chase - reduce hooking mortality
D. Kenyon
Fisheries ManagementFisheries Management
• Habitat Improvement - habitat altered due to dams, dredging, historic logging activity, erosion, shoreline armoring, etc.
Fisheries ManagementFisheries Management
• Habitat Improvement - habitat altered due to dams, dredging, historic, logging activity, erosion, shoreline armoring, etc.
Projects: dam removals bank stabilization tree drops
Lake Michigan FisheryLake Michigan FisheryForage Base 2010Acoustic (open water) survey (Warner et al. 2011) • Good news:strong year class of alewife
total biomass higher than in recent years• Bad news: smelt and bloaters still low
total biomass ~50% of average from 1992-2004Bottom trawl survey (Bunnell et al. 2011)• Bad news: total biomass low and similar to 2009
most abundant species = round goby
Yale.edu
Lake Michigan FisheryLake Michigan Fishery
Round goby
Bloater
Alewife
Ninespine stickleback
Rainbow smelt
Slimy sculpin
Deepwater sculpin
BOTTOM TRAWL
46% native
Alewife
Bloater
Rainbow smelt
ACOUSTIC
8% native
Lake Michigan FisheryLake Michigan Fishery
Chinook Salmon (Claramunt et al. 2010)• Stocking levels reduced since 1998• Variable survival, fishing effort, & natural reproduction• Natural reproduction average = 44%
Lake Michigan FisheryLake Michigan FisheryLittle Manistee Weir Returns
0
10,000
20,000
30,000
40,000
1968 1978 1988 1998 2008Year
# C
hin
oo
k s
alm
on
Invasive SpeciesInvasive Species
Asian Carp – BackgroundAsian Carp – Background
Bighead
Silver
• Introduced to U.S. in 1970s
• Eat plankton
• Tolerant of cold water
• Often found in large, turbid rivers
• Potential vectors Chicago waterway Intentional release
Asian Carp - ResponseAsian Carp - Response• Electrical barriers• Fence construction• Lawsuit to close locks MI, OH, WI, MN, and PA• Illegal to possess or transport any live Asian carp in MI
$10,000 fine• Research• DNR mgmt plan
Wisconsin Sea Grant
Quagga MusselsQuagga Mussels
• Same genus (Dreissena) as zebra mussels
• Native to Caspian Sea and tributaries
• Arrived in Lake Michigan around 1997
• Can colonize hard and soft substrates
• Eat algae
Quagga MusselsQuagga Mussels
• Rapidly expanded in Lake Michigan
• Average lake-wide biomass density increased by >800% from 2004 to 2007 (Bunnell et al. 2009)
- fish biomass density declined by 71%
• Not limited to shallow water out to 400 ft
• Biomass of mussels much lower in 2010 than in 2007 (Good News!)
USFS
Quagga MusselsQuagga Mussels
How do quagga mussels affect aquatic ecosystems? 1. Eat algae
less food for zooplanktonless zooplankton for planktivorous fishes
2. Increase water clarityincreased plant growth
3. Excrete pseudofecesdecrease oxygen and pHincrease pollutant concentrations
4. Colonize pipes, boats, docks, etc.expensive and time consuming
Idaho Dept. of Agriculture
Starry StonewortStarry Stonewort
NY Sea Grant
michiganlakeinfo.com
• Algae – similar to Chara• Native to Europe• Found in Lake St. Clair in 1974• Spread to many inland lakes in last 15 years
boats, trailers, waterfowl• Proliferates rapidly• Forms dense mats in water depths up to 27 ft
Pullman & Crawford 2010
Pullman & Crawford 2010
Starry StonewortStarry Stonewort
Starry StonewortStarry Stonewort
Effects on Aquatic Ecosystems1. Reduces diversity of rooted aquatic plants2. Competes with planktonic algae for nutrients
increased water clarity3. Destroys spawning habitat for bass and bluegills4. Oxygen depletion fish kills5. Interferes with navigation
michiganlakeinfo.com
Starry StonewortStarry Stonewort
Control Options• Mechanical harvesting
• Algaecides“haircuts”
• Other herbicides?timing important
• Drawdowns?
www.aquamog.com
www.prolakemgt.com
VHS VirusVHS Virus• VHSv = viral hemorrhagic septicemia virus• Pathogen that can cause major fish kills
- especially dangerous in hatcheries• Originally from maritime region of Canada• Probably transported to Great Lakes in ballast water• Since 2005, VHS found in Lake Erie, Detroit River, Lake St. Clair, Lake Huron, Lake Michigan (WI), and 2 inland lakes
Wisconsin DNRD. Kenyon
VHS VirusVHS Virus
What are the symptoms of VHS?widespread hemorrhagesdroopy eyelids
Will the virus affect humans?No. The virus dies at human body temperatures.
How does the disease spread between waters?moving infected fish or infected water
What can be done once VHS is in a lake?Nothing! No way to eradicate virus.
VHS VirusVHS Virus
DNR Response1. Restricted movement of baitfish and roe via FO-245.2. Collected fish from numerous waters for VHSv testing3. Disinfected salmonid eggs before entering hatcheries4. Temporarily ceased stocking of northern pike and walleye5. Limited walleye stocking for a few years
- reduce risk of bringing VHSv into a hatchery or rearing pond- walleye only stocked below lowermost dams
i.e., sites with Great Lakes access6. Finally back to full walleye program in 2011
- walleye not very susceptible to VHSv
Invasive SpeciesInvasive Species
What can I do to help?1. Do not release live baitfish into any body of water.2. Dispose of unwanted baitfish and fish parts in trash.3. Do not move water between water bodies.
drain boat, live well, trailer, etc.4. Clean boats, trailers, and equipment. Disinfect live wells and bilges.5. All everything to dry thoroughly.
Minnesota DNRD. Kenyon
Thank You
www.michigan.gov/dnr
Great Lakes, Great Times, Great Outdoors