Lakes, Lake Winnipeg, Eutrophication Notes

Question 1

What is the difference between eutrophication lakes and oligotrophic lakes?

Answer 1

Eutrophic
- has high nutrients
- murkier water
- light can’t penetrate that deep (looks green)

Oligotrophic
- low nutrients
- clear water
- light penetrates deep (looks blue)

Question 2

What is eutrophication?

Answer 2

Adding excess amounts of nutrients into a lake resulting in rapid plant growth (algae) and death of animal life from lack of oxygen.

Phosphorus and nitrogen‼️

Question 3

What is cultural eutrophication?

Answer 3

When humans accelerate the process of eutrophication

Ex. Nitrogen compounds produced by cars and factories

Question 4

Lake Winnipeg in the __th largest lake in the world

Answer 4

10th largest lake in the world

Question 5

How much watershed does lake Winnipeg have in km2 (squared)

Answer 5

1 million km2 (squared)

Question 6

What are 2 features of lake Winnipeg that help reduce negative effects of nutrients?

Answer 6

1. It is relatively shallow and very large (causes lots of mixing things around)
2. Relatively low residence time (fish usually only there for about 3.5 years)

Question 7

What is liebigs law of the minimum?

Answer 7

Growth is usually limited by only one nutrient at a time

Question 8

How many outlets does lake Winnipeg have?

Answer 8

1 outlet - The Nelson River

Question 9

What percentage of phosphorus in lake Winnipeg comes from the Red River?

Answer 9

66-68% of phosphorus

Question 10

What season does most of the phosphorus enter Lake Winnipeg?

Answer 10

Spring