1. Lakes and Ponds

2. Formation of lakes Glacier lakes Oxbow lakes Playas Man-made lakes
Taal volcano lake
Mitchigan lake
Glacier lakes Oxbow lakes
Playas Man-made lakes
Grasmere lake
Silver lake
Lake lamonia

3. How Does Glaciation Work?
Glaciers move they act as scouring pads
10,000 years ago, glaciers began to retreat
Left behind large deposits of ice in hollows between hills which later melted to create lakes.
The Seven Rila Lakes Rila, Bulgaria
Lake Jokulsarlon, Iceland

4. Glacier Lakes
Carved out by glaciers (glaciation), which fill with water
Northern U.S. and Canada

5. The Great Lakes in northern U. S
The Great Lakes in northern U.S. are the largest glacial lakes in the world.

6. Oxbow Lakes Formed by meandering rivers Loops of river gets cut off
Lakes are long and narrow, and usually U-shaped
Common in low valleys and flat coastal areas

7. Oxbow Lake
An oxbow in the making: meanders and sandbank deposition on the Nowitna River, Alaska

8. How Does an Oxbow Lake Form?
(1) On the inside of the loop, the river travels more slowly leading to deposition of silt.

9. (2) Meanwhile water on the outside edges tends to flow faster, which erodes the banks making the meander even wider.
(3) Over time the loop of the meander widens until the neck vanishes altogether.

10. (4) Then the meander is removed from the river's current and the horseshoe shaped oxbow lake is formed.
-- Without a current to move the water along, sediment builds up along the banks and fills in the lake.

11. Oxbow Lake
Oxbow lake and the Chippewa River in Eau Claire, Wisconsin.

12. Playas Formed from multiple things that leave a depression
Sandhill cranes winter in playa lakes
Playas
Formed from multiple things that leave a depression
Soil erosion, wind, animal herds
Small, shallow, and circular
Common in dry plains areas
These lakes are ephemeral, and only form at certain times of the year

13. Playas are important habitat for migratory birds and waterfowl.
The Red-winged Blackbird, Blue-winged Teal, and the Mallard can all be found in playa lakes at some time of the year. 

14. Playa lakes in Kansas agricultural area

15. Man-Made Lakes Water reservoirs formed from Damming rivers
Old rock quarries or mines
Stock ponds on farms and ranches
Lake Mead is formed as a result of damming the Colorado River by the Hoover Dam in Nevada

16. Zipingpu Dam on the Min River in China

17. Natural Lakes in Texas
*Largest designated natural lake Sabine Lake, Sabine and Neches rivers
*Green Lake-10,000 acres is one of the state’s largest natural freshwater lakes
*Caddo Lake, Texas-Louisiana border, was a natural lake originally, Natural Dam Lake
*East Texas & Rio Grande in the lower valley small natural lakes formed by “horse-shoe” bends – aka ?
*South Plains & West of San Angelo are lakes or "playas," such as Big Lake that are usually dry.
6,000 acres /11 hrs by heli

18. Lake Baikal
Crater Lake , Oregon

19. Lentic Habitats Characterized by The shoreline The sides of the basin
The surface of the water
The bottom sediments

20. Zones of Lentic Habitats
Littoral zone
Limnetic zone
Profundal zone

21. Littoral Zone Along shore where light can penetrate to the bottom
Rooted plants can grow
Shores have coarse sediments from action of waves
Sheltered areas have finer sediments (silt and clay) – plant growth in this zone
Animal life includes
Invertebrates common to lotic habitats
Small fish

23. Limnetic Zone Upper open water area of a pond or lake
Lack of rooted plants because light can’t penetrate the bottom
Plankton and fish are common

24. Profundal Zone Deep, bottom-water area No light penetration
No photosynthetic organisms or rooted plants
Sediments are silt and clay mixed with organic matter that settles to the bottom
Organisms living here are tolerant of little or no light or oxygen.

26. Biological Productivity
The amount of plankton, algae, aquatic macroinvertebrates and fish that a body of water can produce and sustain
Usually limited to the depth of light penetration
Light penetration is limited by color of the water and amount of suspended solids
??? - Chlorophyll A & Water Clarity (turbidity)

27. Ponds vs. Lakes
Pond = body of water where light penetrates all the way to the bottom
Lake = depth of light penetration varies from several inches to several feet

28. Characteristics of Biological Productivity
4 categories of lake classification based on biological productivity
Oligotrophic
Mesotrophic
Eutrophic
hypereutrophic

29. Oligotrophic Lakes Nutrient level and productivity is low
Water is clear
Low aquatic plants and plankton
Few fish
Sandy bottoms with little organic material

31. Mesotrophic Lakes Nutrients and productivity is moderate
Some aquatic plants
Water clarity is becoming somewhat cloudy

32. Littoral habitat in a mesotrophic lake

33. Eutrophic Lakes Nutrient level and productivity is high
Large populations of algae, plankton, fish, plants, and macroinvertebrates
Frequent plankton blooms
Sediments with high organic matter
Water is commonly colored

35. Hypereutrophic Nutrient levels and productivity are very high
Large populations of aquatic plants and animals
Frequent plankton blooms
Sediments with most organic matter

36. Ponds and Shallow Lakes
Temperature and dissolved oxygen remains about the same from top to bottom
Water is easily mixed by the wind
Photosynthesis and plant growth can occur from top to bottom (since light can penetrate all the way down)

37. Deep Lakes
Water temperature and dissolved oxygen levels can remain same from top to bottom layers in the winter
During warm summer months, layers form
The surface if warmed up by the sun
Denser, colder water remains below it
Doesn’t get mixed by the wind

38. Mono Lake
Dal Lake
Okanagan Lake
Lake Titicaca 

39. Fall Turnover

40. Effects of Turnovers
Mixing of once layered water returns oxygen levels to the deep areas.
Areas in the south have one turnover per year in the fall.
In the north, lakes become stratified in the summer and the winter (because ice forms on the surface, causing inverse stratification). Thus, there are two turnovers (fall and spring).

41. https://youtu.be/_Ww6BIy3nc0?t=35s

42. Zones of Stratification
Three distinct layers form in deep lakes during the summer months:
Epilimnion
Metalimnion
Hypolimnion

43. Epilimnion Warmest zone near the surface
Circulates freely with varying temperatures according to location on the globe
Wind and currents mix surface water
Most organisms found in this layer
Area of greatest productivity
Greatest light penetration
Greatest oxygen content

44. Metalimnion Middle layer
Steep declines in temperature (area of the thermocline)
Temp. decreases 1oC per meter of depth

45. Hypolimnion Third layer
Deep and cold with little to no temperature change
Low oxygen due to few or no plants
Little to no mixing by wind
Bottom-dwelling organisms and bacteria feed on organic matter and further deplete the oxygen
Little or no light penetration

46. Ecological Succession
Lakes and ponds evolve differently then flowing water ecosystems.
Over time, sediments become higher on the floor of ponds and lakes, and build up. The shallower the lake becomes, the further light can penetrate, so more plants grow on the bottom.
Water tolerant plants and shrubs move in.
Marshes, swamps, and bogs are usually the mature stage of a lake.

47. A lake gradually fills with organic and inorganic sediments, shrinking the area of the pond
A bog forms, then a marshy area
Finally, a meadow completes the succession stages

48. Types of ponds Cypress Ponds Bog Ponds Meadow-Stream Ponds
Mountain Ponds
Farm Ponds

49. 1. Cypress Ponds 2. Bog Ponds
Commonly found in the central or lower Mississippi Basin
Waters are described as being brownish in color
Many dry out during parts of the year.
Willows, bay trees mixed with cypress trees, grow along the shore and are often found out in the waters.
Cypress Pond ,Alabama
2. Bog Ponds
found in the moist temperature regions of North America.
Water is highly acidic and often muddy.
Alders and cedar trees dominate
Floating-leaf plants usually cover the surface.

50. 3. Meadow-Stream Ponds 4. Mountain Ponds
Where streams widen and the speeds of its currents slow down tremendously.
The shallow part of the pond usually has an abundance of pondweeds, cattails, stonewort's and other plants.
Floating leafy plants on the surface of the water, such as lilies and water shields.
4. Mountain Ponds
Formed by glaciers
Bottoms range from being rocky, graveled or muddy.
ice in them and they usually dry up at some point during the summer.
variety of animals and plants live in these icy waters.

51. 5. Farm Ponds Man-made ponds built to help keep the farmlands fertile.
spillway to control the water level.
Farm ponds usually become abundant in fish, and are usually good waters for swimming and boating.
fill from seepage, not from another stream which would fill the basin of the pond with silt and eventually kill the pond.

52. Animals in Lakes and Ponds
Bitterling 
Bullfrog
Green and Gold
Bell Frog 
Common Carp
Largemouth Bass 
Great Crested Grebe 
Great White Pelican 
Zambesi Softshell 
Platypus
Lake Trout