Synopsis Students will observe that muddy water blocks sunlight. They will consider ways that soil might get into water and make inferences about effects on underwater grasses, crabs, and other animals. When sediment from soil erosion enters the Chesapeake Bay and its tributaries, it blocks sunlight that eelgrass and other submerged aquatic plants need. Without these underwater plants young aquatic animals lack protective habitat and sufficient dissolved oxygen. Show crab shells, seahorse, artificial eelgrass.
Students discuss the value of eelgrass as habitat for crabs, seahorses, etc.
Show jar of clear, clean water and jar of muddy water. Demonstrate in darkened room using flashlight projecting through clean water onto wall and not passing through muddy water. Narrate and direct action of play. Pass out craft materials. Students assemble a paper collage of a blue crab in an eelgrass environment with sun overhead.