410 likes | 625 Views
UST 259 Lecture 5. Lake Erie and the Islands: Chapters 13-15. Great Lakes - Watershed. Great Lakes. Lake Michigan Lake Huron Lake Erie* - Smallest of the Great Lakes Lake Ontario Lake Superior. Lake Erie. Human Utility 100 billion gallons water/Day for urban/industrial
E N D
UST 259Lecture 5 Lake Erie and the Islands: Chapters 13-15
Great Lakes • Lake Michigan • Lake Huron • Lake Erie* - Smallest of the Great Lakes • Lake Ontario • Lake Superior
Lake Erie • Human Utility • 100 billion gallons water/Day for urban/industrial • Approx. 50 million Lbs. fish caught/ Annually by US&CA • Human Impact • Polluted effluent • Agric., urban, & Industrial run-off • Ohio owns 3,500 Miles2 (largest US landowner.)
Shape of Lake Erie • Long, narrow • 240 miles x 57 miles • Like a river connecting Lake Huron to Ontario
Lake Erie’s 3 Basins • Depth difference due to??? • Eastern Basin • Soft Devonian, Mississipianshales • Central Basin • Still shales, but wider basin resulted in less glacial impact • Western Basin • Silurian & Devonian limestone & dolomite
Water Quality & Flow • #1 water source for Lake Erie (over 90%) • Detroit River (drains Lake St. Clair & upper lakes) • 219,000 cubic feet/second • Strong flow results in currents in western lake (strong winds also influence surface currents) • Eddies along sides cause pollutants to be greater along shoreline, particularly in MI & Ontario due to water retention • #2 source of water • Maumee River • 4,700 cubic feet/second • Carries 37% of sediment loading
Water Quality & Flow • Water temperature • Approx. 32F (winter) • to 75F (summer) • Ice • Up to 2ft thick on 100% of lake during severe winters • Commercial navigation ends from December through March • Deeper areas of lake have temperature gradations • Dissolved O2 • Varies with temperature, pollution level
Pollution Effects • Nutrient loading • Pesticides • Agricultural fertilizers • Industrial heavy metals • Algae growth • Results in eutrophication (algae deplete O2 supply) • Impacts on fauna • Only pollution tolerant species survive • Lake flow & recharge rate…not enough to offset pollution…why? • 40% of Lake flows to Niagara Falls/year • Takes just over 2 years to completely refill the lake
Lake Erie – Smallest of the Great Lakes - 13th largest body of fresh water on the planet. Cleveland City Center The former Ohio and Erie Canal. And the modern day Towpath Trail system. Cuyahoga River Valley
Cleveland – 77 square miles. Even with population decline, Cuyahoga remains the 27th most heavily populated county in the U.S. Greater Cleveland region being 9th most heavily populated in U.S. Cleveland City Center Cuyahoga River Valley
Shore erosion & storm impact • High water of 1970’s = high erosion levels • Resulted in relocation 60 ft. inland of Coast Guard lighthouse on S. of S. Bass Island (due to erosion) • Waves follow wind…influences water current. Why?
Animal & Plant life • Plankton…plentiful in Lake • Phytoplankton (diatoms, blue-green algae) phyto = plant • Zooplankton (micro. Crustaceans, rotifers, protozoans) zoo = animals • Large populations are present of both • “bottom” of food chain
Animal & Plant life • Invertebrates (mainly benthic fauna of Western basin) • Mostly pollution tolerant species (midge larvae, fingernail clams, sludge worms, snails) • Signs of improvement (mayfly nymphs, larger clams, caddis fly larvae)
Animal & Plant life • Fish • Historically important fishery due to temperature & water chemistry • Spawning/nursery grounds restock lake and maintain populations • Perch, Smallmouth & White Bass, Channel catfish, and others now
Fishery Deterioration • Due to • Watershed erosion & siltation , dam construction, dikes in wetlands • Reduced dissolved O2 due to pollution • Competition from invasive species • Increased/more efficient fishing techniques
Animal Life • Amphibians/Reptiles • Mudpuppy, frogs, salamanders, newts, toads, • Lake Erie water snake • Waterfowl/Birds • Important migratory flyway! • Herons, gulls, egrets, cormorants • Mammals • Very scarce on Erie Islands • Norway Rat, Black & gray squirrels, cottontail rabbits
Plant Life • More than 850 species of vascular plants • Vascular plants: flowering plants, ferns, pines, deciduous trees • Common N. American species dominate • Some invasives & imports • Yellow water lilies • Orchards & vineyards
Island Climate • Unique microclimate • When compared with mainland Ohio: • Annual mean temp. range > than mainland • Daily min/max range < than mainland • Less precipitation • Longer frost-free season • South Bass Island (Put-in-Bay) = approx. 205 days/yr • Bucyrus (50 miles inland) = 154 days frost-free/yr • Colder in winter, warmer in summer • Drier year ‘round
Lake Erie Island Caves • 37 small caves in total • Naturally occurring acids + Groundwater + thousands of years = Erosion of limestone & dolomite = cave formation • Crystal cave • South Bass Island • (Put-in-Bay)
Erie Island Cliffs • Comprised of Limestone & dolomite • Why is this logical? • Cliffs created by? • Action of waves, particularly on W. side of islands
Field Trip: Garfield Park Reservation:Urban Forest Exercise 5 Research Paper Movie- Home http://home-2009.com/us/index.html