Exploring the relationship between native smallmouth bass and invasive mussels in the Huron Erie Corridor Nick Popoff Michigan Department of Natural Resources
What is a Fishery? Fish Peop le Habitat Fishery Social and Economic Benefits
Social and Economic Benefits in HEC Food: Harvest fisheries (yellow perch and walleye) provide important source of protein Finance: Economic activity generated by St. Clair system fishery in 2004 >$36 million (Michigan waters only) Fun: Fishing is fun = recreational fishery Having fun = physical/mental benefits for people Function: Ecological functions of fish benefit society Important indicators of ecosystem health Healthy fish populations = more stable ecosystem
Aquatic Invasive Species A species that is not native and whose introduction causes or is likely to cause harm: Economic Environmental Human health
Management/Control Cost Total = over $2.5 billion over 20 years
Smallmouth Bass and Dreissenid Mussels Context Dreissenid Mussels: zebra and quagga Biological effects HEC response Smallmouth bass Other considerations
Huron-Erie Corridor
Good Access
Some Context Complex ecosystem with much change: 1. Diverse sport fishery 2. Invasive species 3. Land use 4. Dense human populations Bottom Line: This is a challenging system to monitor, understand and manage
Dreissenid Mussels Wikimedia commons LakePro Inc.
Dreissenid Mussels Zebra mussels arrived via ballast in the late 80 s and Quagga s followed Fully established in HEC by mid 90 s Flipped ecosystem on its side Nutrient uptake Water clarity Plant growth USGS
Response in HEC Destroyed native mussel community. Energy shift from pelagic to benthic. Clear water = more plant growth. Opened the door to other invaders like round goby. Significantly reduced populations of native benthic fish like johnny darters and log perch. Smallmouth bass and muskellunge fisheries are world class.
Rooted Aquatic Plants 1. 1978 plant growth limited to Anchor Bay and the delta. 2. By 1990 and 1994 plants had expanded distribution across most of the lake. 3. Dreissenid Mussels increased water clarity increased plant growth improved nursery and habitat for smallmouth bass and muskellunge 1978
Smallmouth Bass ~40% of the boat fishery effort >100,000 legal-sized smallmouth bass caught annually from Michigan waters of Lake St. Clair >90% of legal-size smallmouth bass are released Fishery attracts out-of-state anglers, tournaments
LSC Smallmouth Bass Growth 25 Post-Goby Pre-Goby 20 State Average Total length (in.) 15 10 5 0 2 3 4 5 6 7 8 9 10 11 12 13 14 Age
Fishing Effort Angler hours per acre 25 20 15 10 5 0 0.02 0.38 0.41 Lake Superior Lake Michigan 9.8 Lake Huron Lake Erie 22.88 St. Clair System
2014 Charter Boat Fishery Species targeted by SCDRS Charter Excursions Other 3% Smallmouth Bass 36% Yellow perch 5% Muskie 26% Walleye 30%
Other Changes Lake Huron Effect. Alewives Water clarity continues to improve Angler Behavior More catch-and-release fishing for SMB and MUS Fishing Regulations Catch-and-Immediate Release bass season One Muskellunge/year Northern Pike bag limit Quagga Mussels much higher densities than Zebra Mussels Round Gobies
Concluding Thoughts Zebra/Quagga mussels have a significant ecological impact Nutrients trapped in sediment; improved water clarity; increased plant growth; facilitated round goby explosion Smallmouth bass fishery is world class but HEC is in a state of flux Can dreissenid mussels be controlled?
Concluding Thoughts New technologies currently being explored to treat zebra/quagga mussels Invasive Mussel Collaborative established GLC, GLFC, USGS, NOAA, Tribes, provincial, states
Thank You!!!! Nick Popoff popoffn@mighigan.gov (517) 284-6235