Michigan Fisheries: The Big Picture

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

2. 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

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

4. Fisheries Management • Habitat Improvement • - habitat altered due to dams, dredging, historic, • logging activity, erosion, shoreline armoring, etc. Projects: dam removals bank stabilization tree drops

5. Lake Michigan Fishery Yale.edu • 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 1992-2004 • Bottom trawl survey (Bunnell et al. 2011) • Bad news: total biomass low and similar to 2009 • most abundant species = round goby

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

7. Lake Michigan Fishery • Chinook Salmon(Claramunt et al. 2010) • Stocking levels reduced since 1998 • Variable survival, fishing effort, & natural reproduction • Natural reproduction average = 44%

8. Lake Michigan Fishery

9. Invasive Species

10. Asian Carp – Background • Introduced to U.S. in 1970s • Eat plankton • Tolerant of cold water • Often found in large, turbid • rivers • Potential vectors • Chicago waterway • Intentional release Bighead Silver

11. Wisconsin Sea Grant 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

12. 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

13. USFS 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!)

14. 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

15. michiganlakeinfo.com Starry Stonewort • 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 NY Sea Grant

16. Starry Stonewort

17. Starry Stonewort • Effects on Aquatic Ecosystems • Reduces diversity of rooted aquatic plants • 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

18. Starry Stonewort • Control Options • Mechanical harvesting • Algaecides • “haircuts” • Other herbicides? • timing important • Drawdowns? www.aquamog.com www.prolakemgt.com

19. 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

20. 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.

21. VHS Virus • DNR Response • Restricted movement of baitfish and roe via FO-245. • Collected fish from numerous waters for VHSv testing • Disinfected salmonid eggs before entering hatcheries • Temporarily ceased stocking of northern pike and walleye • 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 2011 • - walleye not very susceptible to VHSv

22. Invasive Species • What can I do to help? • Do not release live baitfish into any body of water. • Dispose of unwanted baitfish and fish parts in trash. • 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

23. Thank You www.michigan.gov/dnr Great Lakes, Great Times, Great Outdoors