limnology 101 n.
Skip this Video
Loading SlideShow in 5 Seconds..
Limnology 101 PowerPoint Presentation
Download Presentation
Limnology 101

Loading in 2 Seconds...

play fullscreen
1 / 31

Limnology 101 - PowerPoint PPT Presentation

  • Uploaded on

University of Missouri-Columbia. Limnology 101. Dan Obrecht MU Limnology The Missouri Department of Natural Resources.

I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
Download Presentation

PowerPoint Slideshow about 'Limnology 101' - Sophia

An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.

- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
limnology 101

University of Missouri-Columbia

Limnology 101

Dan Obrecht

MU Limnology

The Missouri Department of Natural Resources

Region VII, US Environmental Protection Agency, through the Missouri Department of Natural Resources, has provided partial funding for this project under Section 319 of the Clean Water Act

Limnology is the science dealing with the physical, chemical, biological and meteorological study of inland waters.
lake types
“Lake Types”
  • Glaciated Lakes
  • Reservoirs
  • Oxbows

Glaciated Lake



how do the lake types differ
How do the lake types differ?
  • Depth
  • Residence Time
  • Lifespan
  • Glaciated Lakes = Deep relative to area
  • Reservoirs = Vary, but often shallow for a given size relative to glaciated lake
  • Oxbow = Shallow
why is depth important
Why is depth important?
  • Shallow lakes may mix sporadically throughout the summer, leading to more internal loading of nutrients.
  • A deeper lake has a larger volume of water, which influences hydrology.
Residence Time is the theoretical time it takes water to move through the waterbody. It is the reciprocal of Flushing Rate.
residence time
Residence Time
  • Glaciated Lakes = Moderate to high residence times
  • Reservoirs = Generally low to moderate residence times
  • Oxbows = Varies with connectivity to river, generally low due to low volumes
why is residence time important
Why is Residence Time important?
  • Residence time can be used to gauge inputs relative to lake volume. A lake with a long residence time has low inputs, while a lake with a short residence time has greater inputs relative to lake volume.
Residence time also indicates how much sedimentation can occur. A long residence time translates to more material settling out to the bottom of the lake. A short residence time means this sedimentation does not occur.


Over time, lakes become shallower as organic and inorganic matter settles to the bottom. As the lake becomes shallower, it also becomes more productive; accelerating the rate of sedimentation. At some point the lake becomes a wetland.

  • Glaciated Lakes = High lifespan
  • Reservoirs = Short to moderate lifespan
  • Oxbow = Short lifespan

Missouri Lakes –

Phosphorus vs Algal Biomass


Missouri Lakes –

Nitrogen vs Algal Biomass

algae aren t all bad
Algae aren’t all bad!
  • Base of the food web
  • Source of dissolved oxygen
impairments associated with excess algae
Impairments associated with excess algae
  • Loss of aesthetic beauty
  • Decreased recreation
  • Taste and odor problems
  • Increased cost to treat for drinking water
  • Impacts on dissolved oxygen
  • Toxins
where do the nutrients come from
Where do the nutrients come from?

According to the EPA, the three top sources of pollution impairing lakes and reservoirs in the USA are:

trophic state classification
Trophic State Classification
  • Oligotrophic = low nutrients, low algal biomass, high clarity, dissolved oxygen throughout water column
  • Mesotrophic = moderate nutrients and algal biomass, some clarity
trophic state classification1
Trophic State Classification
  • Eutrophic = rich in nutrients and algal biomass, turbid, loss of dissolved oxygen in lower layer during summer stratification
  • Hypereutrophic = very nutrient rich, algal biomass levels that have a negative impact on lake use
Eutrophication: The process of lake aging, in which productivity increases overtime as the lake becomes shallower.