Objectives

• experiment with two underwater research techniques
• understand the concepts of diversity and abundance

Vocabulary

• transect
• quadrat
• diversity
• abundance

Background
Two of the research methods SFS students at the South Caicos research site use to study the coral reef are the transect, or line survey, and the quadrat, or square survey. The line survey is used to study diversity—how many different types of animals are on the reef. The square survey is used to study abundance—how many of each type of animal lives on the reef. To conduct a transect survey, researchers measure a length of string or rope and lay it down on the area to be studied. Then they identify, count and record each species that the transect line touches. At the research site, transect lines are laid on the reef, and SFS students use underwater slates to record the types and numbers of corals they identify along the transect line. This information will be used to compare diversity in coral communities at various locations around the island.

To conduct a quadrat survey, researchers construct a square and place it in the study area. For underwater research, the squares are usually made of plastic plumbing tubes and joints, weighted with sand. The researchers then identify, count and record the types and numbers of each species within the square. At the research site, quadrat surveys are used to study the abundance and movement of juvenile conch that were raised on a shell-fish farm, then released to the wild.

Materials

• scissors
• string
• poster board
• yardstick
• stapler
• Transect and Quadrat Surveys Worksheets  (click here* for worksheet in Adobe Acrobat Reader)
• green, red, and yellow construction paper

Activity

1. Divide students into teams.
2. Each team will need:

   3 green squares 3 green circles 3 green triangles 3 green stars

   3 red squares 3 red circles 3 red triangles 3 red stars

   3 yellow squares 3 yellow circles 3 yellow triangles 3 yellow stars

3. Have each team measure and cut a three-foot length of string to use for the transect survey.
4. Have each team construct a one-foot square for quadrat survey as follows: Cut four strips of poster board 1.5 inches wide by 15 inches long. Assemble the strips to create a square. Overlap and staple the corners. The inside dimension should be 12” by 12”. Have each team scatter its shapes in an area approximately 3’ by 3’.
5. Have students conduct transect and quadrat surveys using the worksheets.
6. Discuss the results.

* If you do not have Adobe Acrobat reader, download it for free from www.adobe.com