A look at Lake Ecosystems: Give and Take

Objectives:

1. The student will be able to demonstrate that each organism in a lake ecosystem both contributes to and benefits from other organisms in the system

Materials Needed:

• Computers connected to the Internet
• Lakes Worksheet #S-1a (Shoal Ecosystem) and
  Lakes Worksheet #S-1b (Give and Take)

Activity:

Have students work singley or in pairs. Hand out the "Lakes Worksheet #S-1a" and "Lakes Worksheet #S-1b"

Have students closely read and examine the "Freshwater Ecosystems" part of the Lakes section of www.kidfish.bc.ca

On "Lakes Worksheet #S-1a" have students draw a picture that shows the organisms that are described on the worksheet.

Once this is completed, discuss what can be given or taken by the various organisms. Divide the class into groups and encourage discussion as they fill in the chart on "Lakes Worksheet #S-1b".

Below is an answer key. Several of the answers may be contested. For example: Do micro organisms contribute enough carbon dioxide and nutrients that makes it worth noting?