Chapter 8 Aquatic Biodiversity

Natural Capital: Major Life Zones and Vertical Zones in an Ocean

Fig. 6-1a, p. 126

Core Case Study: Why Should We Care About Coral Reefs? Coral reefs form in clear, warm coastal waters of the tropics and subtropics. –Formed by massive colonies of polyps. Figure 8-1

Core Case Study: Why Should We Care About Coral Reefs? Help moderate atmospheric temperature by removing CO 2 from the atmosphere. Act as natural barriers that help protect 14% of the world’s coastlines from erosion by battering waves and storms. Provide habitats for a variety of marine organisms.

Fig. 6-7b, p. 131

Estuaries and Coastal Wetlands: Centers of Productivity Estuaries provide ecological and economic services. –Filter toxic pollutants, excess plant nutrients, sediments, and other pollutants. –Reduce storm damage by absorbing waves and storing excess water produced by storms and tsunamis. –Provide food, habitats and nursery sites for many aquatic species.

Fig. 8-7 All consumers and producers to decomposers Secondary to higher-level consumer Primary to secondary consumer Producer to primary consumer Soft-shelled clam Bacteria Clamworm Zooplankton and small crustaceans Smelt Marsh Periwinkle Phytoplankton Herring gulls Snowy Egret Peregrine falcon Cordgrass Short-billed Dowitcher

Case Study: Dams, Wetlands, Hurricanes, and New Orleans Dams and levees have been built to control water flows in New Orleans. Reduction in natural flow has destroyed natural wetlands. –Causes city to lie below sea-level (up to 3 meters). –Global sea levels have risen almost 0.3 meters since 1900.

Mangrove Forests Figure 6-8

What Kinds of Organisms Live in Aquatic Life Zones? Aquatic systems contain floating, drifting, swimming, bottom-dwelling, and decomposer organisms. –Plankton: important group of weakly swimming, free- floating biota. Phytoplankton (plant), Zooplankton (animal), Ultraplankton (photosynthetic bacteria) –Necton: fish, turtles, whales. –Benthos: bottom dwellers (barnacles, oysters). –Decomposers: breakdown organic compounds (mostly bacteria).

Rocky and Sandy Shores: Living with the Tides Organisms in intertidal zone develop specialized niches to deal with daily changes in: –Wave action Figure 8-9

Human Activities Are Disrupting and Degrading Marine Systems Major threats to marine systems –Coastal development –Overfishing –Runoff of nonpoint source pollution –Point source pollution –Habitat destruction –Introduction of invasive species –Climate change from human activities –Pollution of coastal wetlands and estuaries

Freshwater Life Zones Sunlight Painted turtle Green frog Pond snail Blue-winged teal Muskrat Plankton Northern pike Bloodworms Yellow perch Diving beetle Littoral zone Limnetic zone Profundal zone Benthic zone Fig. 8-15

Types of Lakes: Oligotrophic

Types of Lakes: Eutrophic

Effects of Plant Nutrients on Lakes: Too Much of a Good Thing Plant nutrients from a lake’s environment affect the types and numbers of organisms it can support. Figure 8-16

River Systems  Runoff  Watershed  Drainage basin  Floodplain Rain and snow Source Zone Water Sediment Lake GlacierRapids Waterfall Tributary Flood plain Oxbow lake Salt marsh Delta Ocean Deposited sediment Transition Zone Flood-Plain Zone Fig Source area

Rachel Carson All at last returns to the sea-to Oceanus, the ocean river, like the ever-flowing stream of time, the beginning and the end. End chapter 8