Sequence | Background | Objectives | Materials | Activity | Extensions | Evaluations

TOPIC-TITLE Marine & Aquatic Resources Activities - Where Does a Clam Like To Live? AUTHOR Pamela Albright Ted Albright Karen Jerz Dana Mitchell GRADE SUITABILITY Upper Elementary Middle School SCOPE Environmental Science Social Studies Biology

Sequence Before this activity students should have been introduced to clamming as a viable occupation. Students should also understand various clamming instruments. < < go top

Background Summary Clams are a common item on most seafood menus. However, because clams live buried in the substrate, most people know little about them. Clams are one of the most commercially valuable marine organisms harvested and are very sensitive to sediment type, water quality, and availability of food. Clams are filter-feeders and burrow into sediments and siphon nutrients and oxygen from the water column. < < go top Objectives Students will be able to do the following: Identify seven sediment types common to the intertidal and benthic zone. Identify the type substrate a clam prefers to inhabit. Recognize and identify the adaptations clams have developed, thereby enabling them to survive in a given habitat. < < go top Materials 14 small live clams (soft-shell or cherrystone clams) Seven different sediment samples: clay, gravel, sand, mud, silt, pebbles, or larger rocks Seven to eight small aquaria or clear containers improvised from two- or three-liter clear soda bottles Several gallons of sea water or Instant Ocean® Pint sized Ziploc® plastic bags or clear containers Permanent magic markers < < go top Activity Place the students into cooperative learning teams of four studens per group. Distribute samples of different substrate types to student teams. Have the student groups identify each type sediment they are given and mark the substrates appropriately. Ask the students in which sediments would the clam prefer to live. Have the student teams record their ideas in the form of hypotheses. Ask each team to develop a simple experiment to determine which of at least two different sediment types clams prefer. Example: Place two different sediments in a container. The sediments should be approximately the same thickness. Cover sediments with at least two inches of seawater. Place one or two clams of equal size into each container. Observe the clams to ascertain into which sediment they burrow. Do they both prefer the same one? Do they burrow equally fast? Record observations, including adaptations clams have, enabling them to live in the sediment of their choice. Repeat this process and compare results. Have student teams compare their results with those of other groups. Discuss with the students why certain sediments seem to be preferred, what effect polluted waters have on clams and humans, and what laws are enacted to protect humans from "tainted" clams. < < go top Possible Extension Encourage students to observe the clam's two siphons and to identify which one takes in food and which siphon releases waste. Dissect a clam and trace, in a diagram, the progress of food from the water column through the clam's digestive track to the waste material. Build a "larger-than-life" model of a clam with recycled materials collected on a beach clean-up excursion. Research and write a history of the clamming industry. < < go top Teacher Evaluation Evaluate the quality of group hypotheses and experimental design. Evaluate the organization of the research teams. Did everyone participate equally? < < go top