Michigan Fisheries: The Big Picture Presented by: Brian Gunderman Date: November 8, 2011

Fisheries 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 Management Habitat Improvement - habitat altered due to dams, dredging, historic logging activity, erosion, shoreline armoring, etc.

Fisheries 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 Fishery Forage Base 2010 Acoustic (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 Bottom trawl survey (Bunnell et al. 2011) Bad news:total biomass low and similar to 2009 most abundant species = round goby Yale.edu

Lake Michigan Fishery BOTTOM TRAWL 46% native ACOUSTIC 8% native

Lake 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 Fishery

Invasive Species

Asian 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 - 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 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 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 Mussels How do quagga mussels affect aquatic ecosystems? 1. Eat algae less food for zooplankton less zooplankton for planktivorous fishes 2. Increase water clarity increased plant growth 3. Excrete pseudofeces decrease oxygen and pH increase pollutant concentrations 4. Colonize pipes, boats, docks, etc. expensive and time consuming Idaho Dept. of Agriculture

Starry 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

Starry Stonewort

Effects on Aquatic Ecosystems 1.Reduces diversity of rooted aquatic plants 2.Competes with planktonic algae for nutrients increased water clarity 3. Destroys spawning habitat for bass and bluegills 4. Oxygen depletion  fish kills 5. Interferes with navigation michiganlakeinfo.com

Starry Stonewort Control Options Mechanical harvesting Algaecides “haircuts” Other herbicides? timing important Drawdowns?

VHS 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 DNR D. Kenyon

VHS Virus What are the symptoms of VHS? widespread hemorrhages droopy 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 Virus DNR Response 1.Restricted movement of baitfish and roe via FO Collected fish from numerous waters for VHSv testing 3.Disinfected salmonid eggs before entering hatcheries 4.Temporarily ceased stocking of northern pike and walleye 5.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 access 6. Finally back to full walleye program in walleye not very susceptible to VHSv

Invasive 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 DNR D. Kenyon

Thank You Great Lakes, Great Times, Great Outdoors