Lakes
Lake Tekepo, South Island, New Zealand
Lake
Como,
Italy
Major LAkes of the World
Camp Ernst Lake, Burlington, KY
Cave Run Lake, Morehead, KY
Lake
Cumberland,
Clinton, Laurel,
McCreary,
Pulaski, Russell,
and Wayne
counties in
Kentucky.
Lakes in Kentucky
oligotrophic v.s. eutrophic
Physical properties of Lakes
Most are formed by geological events
The lake dotted/marshy land in North America was created by glacial action
about 10-20 thousand year ago
by gouging holes in the loose soil and leaving ice that shapes lake basins
Humans and animals create lakes by building dams
lakes constantly undergo evolutionary change.
these changes affect the development of plants and animals
Most lakes fill with dead organisms, silt, soil that has been washed i by floods
and streams
Lakes are standing bodies of water that range from ponds, a few square
meters in area, to larger bodies of water
Physical Properties of lakes (cont.)
after it rains, the remaining runs seeps into the ground and runs off into lakes
and rivers
Water levels can vary from each season
precipitation causes fluctuation. the lag from rainfall to level change
can vary from days to years
water in temperate climates usually stratify in the summer
most lakes stratify in the spring
●
this video will explain he the great lakes
ice melts,
the water
warms and sinks to the bottom and mixes with the
might
have been
formed:
water at the bottom of the lake
http://channel.nationalgeographic.com/videos/
carving-great-lakes/
Water is most dense at 39° F
the density of water changes with the temp.
Physical Properties of Lakes (cont.)
most lakes have 3 layers because of the density of the water
upper - Epilimnion - warmest water, lease dense, light penetrates all the
way through causing this layer to be highly productive
Middle - Metalimnion or thermocline - most narrow layer, the water is
colder that the layer above and warmer than the layer below it
Lower - Hypolimnion - the coldest of the 3 layers n the summer, close to
4° C (39.2° F) the summer
physical Properties of Lakes (cont.)
this video will explain what water circulation is in a couple of Aquatic Biomes:
https://www.youtube.com/watch?v=XCh04Mi6gNo
Chemical properties of lakes
Each lake can vary in salinity, oxygen concentration and
nutrient concentration
They can also vary among season changes.
Summerkill- the rapid decay of plants and plankton, this
leads to large reduction of oxygen leading to the death
of many aquatic animals
Winterkill- occurs when oxygen is depleted under the ice
and large amounts of fish will die.
oligotrophic lakes
Poor in Nutrients
High oxygen concentration
The oxygen levels decrease as the temperature increases
Clear and deep
Not very primary productive
Low Phosphorus
These are young lakes
Mesotrophic lakes
Medium amounts of nutrients
mostly clear water
some Algae Blooms
middle aged lakes
warm and cold water animals
Less deep than Oligotrophic
Example: Lake Michigan
Eutrophic lakes
Nutrient rich (nitrates and phosphates)
small amounts of oxygen
high levels of organic matter
Eutrophication- increased rate of supply of organic matter
in an ecosystem
high rates of decomposition in lower parts of the lake
because of lower oxygen levels
https://www.youtube.com/watch?v=6LAT1gLMPu4
Oligotrophic
High Oxygen
Mesotrophic
Eutrophic
High Nutrient
Geological Features
Oligotrophic lakes are lakes that are unproductive with a
poor supply of nutrients and secondary production.
Oligotrophic lakes may become more eutrophic as runoff adds
nutrients and sediments.
Eutrophic lakes have high biological productivity. They have
an abundant amount of aquatic plants due the support of their
excessive nutrients. Those nutrients would include nitrogen
and phosphorus. Eutrophic lakes tend to have more surface
area relative to their depth than oligotrophic lakes have.
Human Impacts
Deforestation can lead to erosion which can lead the changing
of lakes or the creation of new ones. Pollution and
overfishing upset the wild life around and inside lakes,
possibly ending the destruction of the habitat. Runoff from
fertilized lands can cause chemical pollutants, such as
pesticides, to drain into lakes threatening the lives of all
animals around and in the water. Runoffs can also cause
nutrient enrichment, oxygen depletion (loss of oxygen), and
fish kills. Fish kills are when a mass group of fish are
found dead and are often the first sign of environmental
stress.
j
Pollution
Photosynthetic organisms
Rooted and floating plants thrive in the littoral zone while phytoplankton and
cyanobacteria inhabit the limnetic zone further from shore where the water is
too deep to support rooted plants.The phytoplankton are responsible for the
seasonal algae blooms. Fish spend most of their time in the limnetic zone and
visit the littoral zone to feed or reproduce.
Nymphaea alba
waterlily
Elodea canadensis
waterweed
heterotrophic properties
presence of life defined by zones:
littoral(snails,clams,insects,crustaceans,fish,amphibi
ans
limnetic(dominated by phytoplankton and
zooplankton,variety of fish
profundal(lots of dead plankton fall here
Pumpkin fish
Scientific name: Lepomis gibbosus
Native to US and lives primarily NE United States
Eats insects,mosquito larvae, worms, minnow, mollusk and
other smaller pumpkin seeds
In warm, calm, clear, shallow lakes. Travels in schools
bluegill fish
scientific name: Lepomis maerochirus
native to North America. in any water depth and prefers
underwater structures.
omnivores-they eat small aquatic insects/fish, leeches,
crayfish, snails, mayflies, dragonflies.
common east of Rockies,shelters in water plants and shade on
bank.
small mouth bass
scientific name: Micropterus dolomieu
carnivorous-they eat tadpoles, smaller fish, crayfish,insects
and zooplankton
native to US, in cool and clear lakes with rock bottoms.
intolerant of pollution(indicates healthy lake environment)
colloration varies due to water clarity and prey diet
crayfish
scientific name: Paranephrops planifrons
eat dead animals/plants,worms, insects, larvae, fish
eggs,frogs and toads.
3 major families:parastacidae, astacidae, cambaridae. eastern
NA has the most diversity.
nocturnal, omnivorous crustaceans
dragonfly
scientific name: Sympetrum flaveolum
Libellulidae species prefers still water.
pH, chemistry and trophic status affect dragonfly water
preference
*trophic status-degree of enrichment of nutrients
have wings out when resting so they are DIFFERENT from
damselfly.
american bullfrog
scientific name: Rana catesbeiana
nocturnal,carnivores
native to eastern North America
they eat rodents, small reptiles, amphibians, crayfish,
birds, bats, and insects.
PH levels of lakes around us
Springmill Lake- 7.9
Camp Ernst Lake- 8.1
Idlewild Lake- 8.2
Average: 8.06