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

TOPIC-TITLE Marine & Aquatic Habitats Activities - Marine Ecology AUTHOR Trisha Hembree GRADE SUITABILITY Middle School SCOPE Marine Ecology - Habitats

Sequence The students should have completed a brief introduction concerning the diversity and abundance of flora and fauna associated with the marine ecosystem. This activity is intended to be an introduction to a detailed study of the various habitats as well as the advantages and disadvantages of each habitat. Include external influences, including human impact. < < go top

Background Summary All organisms on Earth have their own unique specifications and adaptations necessary to live in specific biological and physical niches. Because these parameters sometimes overlap, competition for space between members of the same and differing species can exist. One result of this competition is the need to increase adaptability to a specific zone. Animals that are sessile spend part or all of their lives secured to some type natural or man-made substrate (surface). These creatures rely on the sea to bring them food, nutrients, and sufficient oxygen. The food upon which most of these animals depend is plankton (phytoplankton and zooplankton), which is comprised of free-floating, microscopic plants and animals. In the plankton-rich waters of the Gulf of Mexico and the southeastern Atlantic, additional stresses exist such as silting, which smothers the animal; currents, which can remove food sources; submarine lithification, which includes the deposition of carbonate cement grains on the aperture; encrustation by competing organisms; toxic emission of mesenterial filaments from the gut of nearby competing colonies; pollution; over exposure to the sun; eutrophication; algal mats; and/or grazing by larger, swimming organisms. < < go top Objectives Students will be able to do the following: Enact the life cycle of a sessile animal. Quantify the possibility of survival under the conditions given. Propose only one, new adaptation in order to increase the chance of survival for each student's animal. Defend that adaptation to the class. < < go top Materials Food cards made of 3" x 5" laminated cards to represent the different foods necessary for each animal's survival. Students exhibiting an artistic talent could draw the major plankton. A jar or box Several handkerchiefs of various colors < < go top Activity Prepare the class for this activity by lecturing on all topics listed in the background summary. Have each student select a card from the jar or box that lists the animal he/she should imitate, what that animal eats, what defense mechanisms the animal has, and other important aspects of the animal. Position each student according to the animal's position in the ecosystem. With the bag of "food," distribute food at random intervals within the classroom. Be sure to talk to the students at this time, informing them of such alterations as current changes, siltation, or other limiting factors. Organisms that do not obtain sufficient food or are impacted by an alteration in their habitat will "die." Death of the organism is simulated by placing a handkerchief on the appropriate student's head. Have students evaluate their "health" quantitatively. Have students present their results to the class. < < go top Possible Extension Students could research and simulate other sessile animals. Students could research and define the types and amounts of food necessary for certain sessile animals and make the food cards themselves. Students can use their talents to draw or trace their own animals. < < go top Teacher Evaluation Students should be able to present a mathematical evaluation of the usable vs. the nonusable food they received. Students should be able to propose a probability of survival and defend their results. Students should use correct vocabulary with their defense and present their choice of one additional adaptation. < < go top