They cull out old, injured and diseased animals, leaving healthier populations to survive and reproduce. They are also very effective scavengers, consuming even garbage and other human debris. The following is a partial list of items that have been removed from the stomachs of sharks. Have students conduct a scavenger hunt in their homes, neighborhoods and around businesses for as many of these items as they can collect. Secure the cooperation of parents or guardians.
Results are best when students work in teams.
Add newspaper clippings about shark-related incidents and magazine photos of sharks in action. Discuss the role of sharks as the ocean's great scavengers. Consider the loss of sharks in terms of human activity. Also according to the program, sand tiger sharks gulp air at the surface in order to hang motionless in the water column. Unlike most fishes, sharks lack gas bladders with which to maintain neutral buoyancy in the water.