Lake Superior Grants No (NSF) and NA06OAR (NOAA) Created by: Helen Domske, NY Sea Grant. Information/Photos: Cindy Hagley and Jeff Gunderson, MN Sea Grant.

Lake Superior NOAA GLERL

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Ecosystem: Generally Good Fisheries good to excellent Lower food web stable Contaminants generally decreasing or stable Forest cover increasing Important designations SOLEC 2011

Lake Superior Ecosystem Challenges Source: MN Sea Grant Round Goby Emerald Ash Borer

Trends in Key Lower Food Web Prey Species Diporeia spp. Mysis diluviana SOLEC 2011

Lake Superior water is clear! Secchi Disk – Measures water transparency – Anything that interferes with light penetration (Particles, algae, sediment) Photo: M. Auer, MTU

Water Clarity

Lake Superior Water Stays Put The average amount of time a drop of water stays in the lake

Pollution implications for Lake Superior Small drainage basin – Less pollution coming in BUT very long retention time – Pollutants accumulate and remain for a long time

Domestic Water Use Navigation Fish Habitat Hydropower Water Use Priorities

A Superior Lake…...

Habitat Photos: UW Extension Source: SOLEC 2011

Coastal Wetlands and Nearshore Areas Critical habitat for fish, aquatic organisms, and wildlife Very productive compared to all other Lake Superior habitats

1 FT 6 IN. Small changes in Water Level Make a BIG difference in Coastal Habitats ….even a difference as small as a few inches

Water Temperature, Air Temperature, and Ice Cover on Lake Superior Figures from Jay Austin, UMD

Lake Superior Erosion

Lake Superior Mining Duluth Superior Ore Dock Source: Minnesota PCA

Habitat Destruction From Mining Operations Open pit mining -- destroys lakes & wetlands, alters watersheds Mining generates waste rock and mine tailings Tailings basin infillings could destroy wetlands and wildlife habitat SOLEC 2011

SHIPPING Lake Superior is connected to the Atlantic Ocean by the St. Lawrence Seaway. The 2,343 mile (3,770 kilometer) trip by boat from Duluth/Superior to the ocean takes about 7 days. Duluth/Superior is the busiest inland port in the country, with more than 1,000 vessels visiting annually. Taconite (pelletized iron ore) and coal are the major domestic cargoes. Taconite is shipped to steel mills on the lower Great Lakes. Low-sulfur western coal is shipped to Michigan, where it is burned to generate electricity. MN Sea Grant

 The introduction of sea lamprey and rainbow smelt, as well as over-fishing, have depleted the populations of whitefish and lake trout that form the core of the Lake Superior fisheries. The sea lamprey control program implemented by Canada and the United States has been quite effective. Source: University of Guelph THE FISHERY  For all its size, Lake Superior has less capacity to support aquatic life than do the other Great Lakes. Lake Superior is ultra-oligotrophic, which means it has less dissolved nutrients available to support aquatic life. As a result, the Lake Superior fishery produces only about 10% of what Lake Michigan, a comparatively nutrient-rich lake, produces annually.

Lake Superior Fishery Change Chemical Pollution Sedimentation Commercial Fishing Recreational Fishing Habitat Loss Climate Change Exotic Species

State of Lake Sturgeon Lake sturgeon numbers are increasing For the first time in 100 years, spawning naturally in St. Louis River Demonstrates progress from 30 years of habitat restoration and stocking efforts Source: MN DNR

Healthy Lake Trout Populations Year Siscowet/1000 m net night Siscowet CPUE Source: Lake Superior Technical Committee data Lake trout and siscowet populations in Lake Superior

Lake Superior Herring Fishery Lake herring also called tullibees or ciscoes Historically, most abundant native fish Harvested across Lake Superior Lake Herring Photo: MN Historical Society

Introduced into a Michigan inland lake in 1912, whose outflow went into Lake Michigan Found in Lake Superior in the 1930s Found along North Shore in 1946, after which populations exploded Rainbow Smelt Introduction

Smelt Impacts Contributed to declines in native fish populations such as lake herring and lake whitefish Herring Fisherman

Unlike the invasion of lamprey, smelt at least created a commercial fishery Pound net in St. Louis River

Pink Salmon Pink salmon “accidentally released” in Thunder Bay in 1956 Currently are naturally reproducing in small numbers Pink Salmon