The Lessons on the Lake Logo Chapter 7: Ecosystems in Delicate Balance
Lesson 7.4 Lesson 7.5 Lesson 7.6 Lesson 7.7 Lesson 7.8 Lesson 7.9 Lesson 7.10
Lesson 7.1 Lesson 7.2 Lesson 7.3
Lessons on the Lake -> Chapter 7 -> Threatened and Endangered Species in the Basin


The Lake Pontchartrain Basin contains many diverse habitat types. Before humans
interfered with the Basin’s ecosystems, these habitats supported an abundance of plant and animal life and were intricately woven together into a vast web of life which supported and complemented each other.

Since humans have developed much of the land surrounding Lake Pontchartrain, these once-connected ecosystems have become isolated, and their delicate balances have become disrupted. As this isolation and disturbance continues, ecosystems become unable to support certain animals, and the animals become threatened, endangered, or extinct.

Threatened Species are those species likely, in the near future, to become
endangered species throughout all or much of their range. The range of an animal is that geographic region in which all of the conditions necessary for its survival are met, e.g., temperature requirements, food supply, habitat availability, clean water, adequate space, etc.

Endangered Species are those species of animals and plants identified by governmental or international organizations as being at risk of extinction because of human activity, changes in climate, changes in predator-prey relationships, etc.

Introduced Species are species native to some other part of the world which have been brought to an area for a particular reason, e.g., ornamental plants or fur-bearing animals. These introduced species usually have some other species which keep them under control in their native lands, but lack these checks and balances when they are introduced into a different place. Without competition or predators to restrict them, introduced species reproduce extremely fast and can ultimately cause an ecosystem to become unstable. Some examples of introduced species in the Lake Pontchartrain Basin are water hyacinths and nutria. These organisms have already damaged the ecosystems into which they were introduced and are costing taxpayers a lot of money in an attempt to keep them under control.
(Refer to Cliff Glockner’s personal observations entitled “The Marsh’s Friend, the Muskrat,” culled from a life of hunting and trapping in the marsh. These observations provide one man’s perspective of the traditional role of muskrat in the marshlands surrounding Lake Pontchartrain.)

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Every day, a manatee will eat 10-15% of its body weight in aquatic vegetation.
  1. Ch. 7 Intro
  2. Essential Questions
  3. Ecosystems
  4. Energy Flow Through an Ecosystem
  5. Healthy vs. Unhealthy Ecosystems
  6. Biodiversity
  7. Threatened and Endangered Species in the Basin
  8. Decision Making and Issue Analysis
  9. Ecosystem Tumble
  10. Activity: I'm a Survivor