current and upcoming issues confronting inland lakes alan steinman, ph.d. annis water resources...
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Current and Upcoming Issues Confronting Inland Lakes
Alan Steinman, Ph.D.
Annis Water Resources Institute, GVSU
Major Issues
Nonpoint source pollution / Stormwater runoff
Invasive species
Landscaping: good, bad, and downright pitiful
Nonpoint Source Pollution
Nonpoint source (NPS) pollution comes from diffuse sources, such as septage, or rainfall and snowmelt moving over and through the ground.
Nonpoint Sources of Pollution
• Excess fertilizers, herbicides, and insecticides from agricultural lands and residential areas
• Sediment from improperly managed construction sites, crop and forest lands, and eroding streambanks
• Livestock, pet wastes, faulty septic systems, atmosphere
• Oil, grease, and toxic chemicals from stormwater runoff
Harmful Algal Blooms (HABs)
• Microcystin is the most common cyanotoxin produced by HABs → hepatoxin and tumor promotor.
• The U.S. currently has no national standards for exposure to microcystin or other algal toxins.
• WHO standards:
- drinking water: 1 µg/L- recreational: 20 µg/L
Microcystin Concentrations
Location Date Concentration (µg/L)
Musk. Lake (open)
7/16/07 34
Musk. Lake (HarborTowne)
7/16/07 158
Mona Lake 7/23/07 317
Data: Rick Rediske, AWRI
Stormwater Facts
Most of the NPS pollution comes during storm events
Stormwater discharges are generated by runoff from land and impervious areas during rainfall and snow events
• Paved streets• Parking lots• Building rooftops
Why Should We Care about Stormwater?
• Reduced recharge to aquifers
• Increased erosion & sedimentation
• Potentially toxic to stream biota
• Cost of infrastructure
Stormwater Examples
Land Use Change Analysis
0
2000
4000
6000
8000
10000
12000
14000
16000
Acres
Com
mer
cial
,In
dust
rial &
Tra
nspo
rtat
ion
Cro
plan
d &
Pas
ture
For
est
Land
Res
iden
tial
Land Use Categories
Spring Lake Land Use Change 1978-2006
1978
2006+79.40%
-42.32%+121.36%
-8.71%
Solutions Low Impact Development (LID) practices
Design natural infiltration to occur as close as possible to the original area of rainfall
Engineer terrain, vegetation, and soil features to optimize natural infiltration, allowing the landscape to retain more of its natural hydrological function
Best management practices, including riparian buffers, swales, rain gardens…
Invasive Species
• 1 new species arrives ~ 8 months1
1Ricciardi, A. 2001. CJFAS 58: 2513-2525.
• change in fish prey/food webs
• economic costs
Data: Tom Nalepa, GLERL
Diporeia
Data: Tom Nalepa, GLERL
Food Web Changes:Lake Michigan
Biomass
(Kilotons)1989 2006 2007
Prey Fish
(alewife; bloater)400 61 30
Quagga/Zebra mussels
0 212 245
Data: USGS, Great Lakes Science Center
Bighead Carp:
• feeds mostly on plankton, including both zooplankton and large, colonial phytoplankton (e.g. cyanobacteria)
• ecological concern over food web changes
Asian CarpAsian Carp
Silver Carp
• feeds mostly on phytoplankton• ecological concern over food web changes
From: Asian Carp Control Strategy Framework (Feb. 2010)
Actual asian carpfound
- all locations currently with confirmed, self-sustaining populations of bighead, silver, grass, or black carp have access to a large river, with at least 80 km that are free-flowing
River length requirement
- Kolar et al. (2007) identified 22 GL rivers “that may be suitable for spawning” based on lack of dams and minimum length of 100 km
- 7 of the 22 are in Lake Michigan:- 2 in the U.P.- 2 in WI- St. Joseph, Grand, and Pere Marquette
Vulnerable river systems?
Drowned rivermouths that could serve as good adult feeding habitat
Nico et al. 2005
- don’t really know how far they move
- usually associated with rapidly increasing flows
- big unknown and serious mgm’t need
Upstream spawning behavior
- thought to be in turbulent areas of rivers
- mouths of tributaries
- probably not in small tributaries
- may occasionally spawn in lakes, but eggs not thought to survive
Spawning location
Nico et al. 2005
• Can tolerate colder water, but Great Lakes temperature regime may be a metabolic limitation
• Need substantial amounts of plankton, so restricted to coastal, riverine areas
• Can they move from one riverine area to another?
Are They a Threat to the Great Lakes?
Submerged Aquatic Vegetation
Submerged Aquatic Vegetation
• Grows up to 1 inch/day• Forms dense mats that block sunlight, killing off native plants below• Dense mats inhibit boating, swimming, & skiing• Slows movement of water, allowing sediment to build • Poor fish habitat • Found close to MI
Hydrilla
http://www.miseagrant.umich.edu/
• Need clear policy that prevents new invasive species from entering Great Lakes
• Need early detection monitoring program in most vulnerable locations—quarantine and eradication likely to be successful
Solutions
Landscaping IssuesLandscaping Issues
Courtesy: Progressive AE
1) Minimize lawn area2) Establish “greenbelt”
Courtesy: Progressive AE
Don’t dump in storm drains
Build a raingarden
Establish a greenbelt
Don’t add phosphorus fertilizer
Don’t dump in storm drains
Maintain greenbelt of trees
Small lawn area
Courtesy: Progressive AE
Minimize hardened shorelinesSeawalls deflect waves;
scour lake bottom
Seawalls prevent animal movement
(frogs)
Seawalls providepoor habitat
Some exotic plants prefer disturbed
habitat
10 Ways to Protect Your Lake:
1) Use no-phosphorus fertilizer
2) Use minimum am’t of recommended fertilizer
3) Apply fertilizer to lawn, not sidewalk
4) Don’t feed waterfowl near lake
10 Ways to Protect Your Lake:
5) Don’t burn leaves/clippings near lake
6) Plant buffer strip at lake’s edge
7) Promote runoff infiltration
8) Maintain wetlands
10 Ways to Protect Your Lake:
9) Maintain your septic system
10) Don’t be complacent
Websites for more information:
• www.michiganlakeinfo.org
• www.shoreline.msu.edu
• www.raingardens.org
www.gvsu.edu/wri
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