Chapter8

What is the largest freshwater lake in the US?

Lake Superior.

How many lakes over 10 acres does Minnesota have?

Over 12,000.

What are the two types of lakes based on nutrient status?

Oligotrophic and Eutrophic.

What does the littoral zone refer to?

The area from shore to where rooted plants no longer grow.

What is the primary producer in the photic zone of a lake?

Phytoplankton.

What is a common consequence of cultural eutrophication?

Excessive nutrient loading leading to algal blooms.

What are the main physical and chemical parameters that affect lake ecosystems?

Hardness, pH, phosphorus, nitrogen, sulfate, dissolved organic matter, oxygen, and water clarity.

What is the term for the layers formed in deep lakes?

Stratification.

What ecological role does Wild Rice play in the littoral zone?

It is an annual grass found in shallow water, influenced by water chemistry.

What are two invasive species mentioned that affect freshwater ecosystems?

Zebra and Quagga Mussels.

What is biomanipulation?

The process of increasing or decreasing populations of certain organisms in an ecosystem.

What human activity is a major cause of eutrophication?

The use of fertilizers leading to nutrient runoff into water bodies.

What is the upper layer of a stratified lake called?

Epilimnion.

What is a significant environmental issue affecting Lake Superior?

Pollution from DDT, PCBs, and invasive species like the sea lamprey.

What percentage of Minnesota's lakes is found in the Northern Lakes and Forests ecoregion?

46%.

What is one conservation measure taken in Minneapolis Chain of Lakes?

Regulating the amount of phosphorus in fertilizers.

What is the aphotic zone?

The lower layer of a lake ecosystem that does not receive enough light for photosynthesis.

What three lake communities are influenced by nutrient levels?

Oligotrophic, mesotrophic, and eutrophic communities.

What does the term 'eutrophication' refer to?

The process of nutrient enrichment in a water body that leads to increased plant growth and potential harm to aquatic ecosystems.