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Transcript of Lakes
Matt and Shelby
you see on and around lakes.
Algae is in the water, on the water, on rocks, logs, dead trees, and aquatic plants.
Algae range from microscopic single celled organisms, to colonial masses visible to the naked eye.
Algae reproduces asexually in the spring, after ice on the lakes thawed.
Algae is an autotroph and uses sunlight, and essential nutrients like phosphorus and nitrogen to maintain homeostasis and reproduce.
Algae is very sensitive to its surroundings. Algae is sometimes nearly wiped out in the winter because of a lack of sunlight, caused by ice covering the lake. Luckily some algae survive.
It's the little
Sensitivity To Environment
Algae has many uses for humans. We can use it to create fertilizer, biofuels, and as an energy source when trying to mass produce an aquatic species. It is also used in waste management facilities to reduce toxins in water sources. However some algae IS toxic, and you should avoid swimming lakes with
Sensitivity To Environment
Sensitivity to Environment
Sensitivity to Environment
Food Web Position
Sensitivity Environmental Insults:
Physical Characteristics of Lakes
Zooplankton live near the surface of the water, but other types of invertebrate may also remain at the bottom of the lake.
36 F north
44 F south
60 F north
70 F south
38 F north
46 F south
6 F north
16 F south
Warmest temperature on record
114 F - Beardsley (July 29, 1917)
114 F - Moorhead (July 6, 1936)
Coldest temperature on record -
-60 F near Tower (February 2, 1996)
The population size of zooplankton changes every day. It is also very hard to get an estimate because of how small the zooplankton are, and because of how large a body of water may be.
Many types of zooplankton can reproduce either sexually OR asexually, based on their environment.
Zooplankton are heterotrophs and feed on phytoplankton to gain nutrients like phosphorus and nitrogen.
Soils and Mineral
Most lake beds consist of bedrock, such as, gneiss, undifferentiated granite, and sedimentary rock.
Zooplankton are sensitive to the environment because when there are harsh conditions, they can reproduce asexually, and when the conditions are normal they reproduce sexually.
Zooplankton are one of the largest freshwater food source, and are essential for fish survival. Without the zooplankton, there would be no fish for us to eat. Some zooplankton can even be used to aid in the cleaning of oil spills.
Texture is course-loamy to course
Average annual precipitation
Northwest: 19 inches/year
Southeast: 34 inches/year
Average annual snowfall
Northeast: 70 inches/year
Southwest: 35 inches/year
Latest spring freeze -
April 29 - metro area
May 27 - far north
Earliest fall freeze -
October 5 - metro area
Depending on the temperature, the surface conditions can be frozen or liquid.
"Topography is dominantly rolling with irregular slopes and many craggy outcrops of bedrock."
The relative humidity typically ranges from 38% (comfortable) to 89% (very humid) over the course of the year
Bacteria mainly resort to the bottom of the lake, because that's where most of the dead plant and animal matter end up.
Yellow perch live in shallow water near the shore line. The shallow waters offer less danger from predators and provide necessary vegetation for the fish.
Yellow perch populations depend on how many were present in the year before. The MN DNR sometimes repopulate lakes by breeding fish and moving them into the lake.
Yellow perch spawn in early and mid May. It takes 2-3 weeks for the eggs to hatch.
The yellow perch's diet consists of zooplankton, minnows, and other small invertebrate.
In the winter when ice covers the lakes, it forces the yellow perch to move into deeper waters. This causes many yellow perch to become easy prey to other larger fish.
The yellow perch is one of Minnesota's most sought after fish. It's easy to cook, tastes good, and is a very commonly caught fish.
There are over 250 million walleye stocked into Minnesota's lakes each year. Not all may survive considering there can be other predators that need to feed.
Walleye spawn over rock and gravel in shallow waters and rivers 1-6 feet deep. They female deposit up to 100,000 eggs, which neither the male or female care for.
Walleye can be found throughout most lakes in Minnesota. They mainly stick to deep waters, but remain in the warmer parts of the water.
Newborn Walleye feed primarily on zooplankton and aquatic bugs. Adult Walleye mainly eat smaller Yellow perch.
Walleye typically thrive in water temperatures between 50-55 degrees Fahrenheit. Windswept lakes with gravel shorelines allows the walleye to reproduce and search for food in open waters. Walleye struggle in the winter because of ice coverings and the decreased temperature of the water.
The Walleye is another majorly sought after fish because of its taste, large size, and enormous population.
Almost impossible to predict, the population of bacteria depends on the amount of dead matter it decomposes.
Bacteria reproduce asexually, so its population grows rapidly and quickly.
Bacteria are heterotrophs, and they feed off of dead plant and animal matter.
Bacteria feed off of dead matter, so if everything died off, bacteria would not survive either.
Bacteria can help humans in many ways. It helps with soil enrichment for farmers, decomposing organic matter, and even toxic waste.
Bacteria is the decomposer in the food web.
Invasive Species Report
Disturbances On Lakes
The watermilfoil creates crowding, and vegetation competition by stealing nutrients from other plants. The invasive species travels easily from lake to lake because of people boating in multiple lakes without cleaning their boat off. Watermilfoil can grow from a single small stem to a large overgrowing population.
Watermilfoil affects the algae in the lakes by overcrowding the habitat of the algae, and competing for nutrients.
With algae population declining from competition and crowding, the zooplankton have less to feed on, causing their population to decline.
The yellow perch will now have less food to eat, with a smaller zooplankton population. More and more yellow perch will end up starving.
With an increased death toll from starving zooplankton and yellow perch, bacteria will end up overcrowding itself by decomposing more and more dead matter.