11:375:101 Lecture Notes - Lecture 10: Intertidal Zone, River Ecosystem, Keystone Species
Document Summary
Build reefs by secreting crusts of limestone around their soft bodies. Provide algae with a home and some nutrients. Help produce the exoskeleton by drawing in co2. Light is captured at different areas and different wavelengths throughout the ocean. If the algae dies, there is no more pigmentation. Nets drag along the ocean floor and rips up whatever is on the ocean floor. Saltwater and freshwater aquatic life zones cover almost of the earth"s surface, with oceans dominating the planet. Saltwater make up 71% of the earth"s surface area. Freshwater makes up about 2% of the earth"s surface area. Key factors determining biodiversity in aquatic systems. Temperature, dissolved oxygen content, availability of food, and access to light and nutrients necessary for photosynthesis. Most of the earth is covered with water. Bottom dwellers: oysters, sea stars, clams, lobsters, crabs, bacteria. Live at the bottom of the ocean. In the light zone and surface waters. Primary producers for most aquatic food webs.