1. Aquatic Biodiversity Part 1—Introduction & Marine Systems

2. General Nature of Aquatic Systems Saltwater and freshwater aquatic life zones cover almost three-fourths of the earth’s surface, with oceans dominating the planet. Key factors determining biodiversity in aquatic systems are 1. Temperature 2. Dissolved oxygen content 3. Availability of food 4. Availability of light, and nutrients necessary for photosynthesis.

3. Most of the Earth Is Covered with Water Aquatic life zones Saltwater life zones (marine life zones) Oceans and estuaries Coastlands and shorelines Coral reefs Mangrove forests Freshwater life zones Lakes Rivers and streams Inland wetlands

4. Fig. 8-2, p. 169 Saltwater: global ocean divided into 4 areas: Atlantic, Pacific, Arctic, Indian. The salty oceans cover 71% of the earth’s surface and contain 97% of the earth’s water. Almost all of the earth’s water is in the interconnected oceans, which cover 90% of the planet’s ocean hemisphere (left) and nearly half of its land-ocean hemisphere (right). Freshwater systems cover less than 2.2% of the earth’s surface (only a fraction of this is drinkable. The Ocean Planet

5. Fig. 8-3, p. 170 Aquatic Systems

6. Where Aquatic Species Live Key factors in the distribution of organisms are Temperature Dissolved oxygen content Availability of food Availability of light and nutrients needed for photosynthesis in the euphotic (photic) zone Turbidity, degree of cloudiness in water, inhibits photosynthesis

7. Most Aquatic Species Live in Top, Middle, or Bottom Layers of Water Plankton—free floating 1. Phytoplankton—primary producers for most aquatic food webs 2. Ultraplankton—tiny photosynthetic bacteria 3. Zooplankton Primary and secondary consumers Single-celled to large invertebrates like jellyfish Nekton—strong swimmers: fish, turtles, whales Benthos—bottom dwellers: oysters, sea stars, clams, lobsters, crabs Decomposers—mostly bacteria

8. Why Are Marine Aquatic Systems Important? Saltwater ecosystems are Irreplaceable reservoirs of biodiversity Provide major ecological and economic services.

9. Oceans Provide Vital Ecological and Economic Resources Estimated $12 trillion per year in goods and services, due to reservoirs of diversity in three major life zones 1. Coastal zone Warm, nutrient rich, shallow Shore to edge of continental shelf Usually high NPP from ample sunlight and nutrients 2. Open sea 3. Ocean bottom

10. Fig. 8-5, p. 172 Which two ecological services and which two economic services do you think are the most important? Why? Major Ecological and Economic Services Provided by Marine Systems

11. Fig. 8-6, p. 173 This diagram illustrates the major life zones and vertical zones. Available light determines the euphotic, bathyal, and abyssal zones. Temperature zones also vary with depth, shown here by the red line. Question: How is an ocean like a rain forest? Major Life Zones and Vertical Zones in an Ocean

12. Estuaries and Coastal Wetlands Are Highly Productive Estuaries and coastal wetlands—seawater mixes with freshwater Very productive ecosystems with high nutrient levels Include: Mouths of rivers Inlets Bays Sounds Salt marshes Mangrove forests

13. Fig. 8-7, p. 173 View of an Estuary from Space

14. Estuaries and Coastal Wetlands Seagrass Beds Grow underwater in shallow areas Support a variety of marine species Stabilize shorelines Reduce wave impact Since 1980, about 29% of the world’s sea grass beds have been lost to pollution and other disturbances. Mangrove forests Along tropical and subtropical coastlines 69 different tree species that grow in saltwater

15. This mangrove forest is in Daintree National Park in Queensland, Australia. The tangled roots and dense vegetation in these coastal forests act like shock absorbers to reduce damage from storms and tsunamis. They also provide highly complex habitat for a diversity of invertebrates and fishes.

16. Estuaries and Coastal Wetlands Offer important ecological and economic services Coastal aquatic systems maintain water quality by filtering Toxic pollutants Excess plant nutrients Sediments Absorb other pollutants Provide food, timber, fuelwood, and habitats Reduce storm damage and coast erosion

17. Rocky and Sandy Shores Host Different Types of Organisms Intertidal zone Rocky shores Sandy shores: barrier beaches Organism adaptations necessary to deal with daily salinity and moisture changes Sand dunes are important

18. Beach flea Peanut worm Tiger beetle Barrier Beach Blue crab Clam Dwarf olive High tide Sandpiper Ghost shrimp Silversides Low tide Mole shrimp White sand macoma Sand dollar Moon snail Rocky Shore Beach Sea star Hermit crab Shore crab High tide Periwinkle Sea urchin Anemone Mussel Low tide Sculpin Barnacles Kelp Sea lettuce Monterey flatworm Nudibranch Stepped Art Fig. 8-11, p. 176 Living between the tides: Specialized Niches

19. Coral Reefs Tiny animals (polyps) and algae have mutualistic relationship Polyps secret calcium carbonate shells, which become coral reefs Habitats for one-fourth of all marine species Marine equivalent of tropical rain forests

20. Important Ecological and Economical Services 1. Moderate atmospheric temperatures 2. Act as natural barriers protecting coasts from erosion 3. Provide habitats 4. Support fishing and tourism businesses 5. Provide jobs and building materials 6. Studied and enjoyed

21. 1.Coastal development 2.Pollution 3.Overfishing 4.Increasing ocean acidity Warmer ocean temperatures and turbidity leading to coral bleaching A bleached coral reef has lost most of its algae because of changes in the environment With the algae gone, the white limestone of the coral skeleton becomes visible. If the environmental stress is not removed and no other algae fill the abandoned niche, the corals die. These diverse and productive ecosystems are being damaged and destroyed at an alarming rate Degradation and Decline

22. Fig. 8-12, p. 177 Gray reef shark Sea nettle Green sea turtle Blue tang Fairy basslet Parrot fish Brittle star Sergeant major Hard corals Algae Banded coral shrimp Phytoplankton Symbiotic algae Coney Zooplankton Blackcap basslet Sponges Moray eel Bacteria Producer to primary consumer Primary to secondary consumer Secondary to higher-level consumer All producers and consumers to decomposers Natural Capital: Some Components and Interactions in a Coral Reef Ecosystem

23. Three Vertical Zones of the Open Sea 1. Euphotic zone—upwelling brings nutrients to euphotic zone Nutrient levels low Dissolved oxygen levels high Phytoplankton 2. Bathyal zone Dimly lit Zooplankton and smaller fishes 3. Abyssal zone Dark and cold High levels of nutrients Little dissolved oxygen Deposit feeders Filter feeders

24. Human Activities Are Disrupting and Degrading Marine Systems Coastal development Overfishing Use of fishing trawlers 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

25. Fig. 8-13, p. 179 Natural Capital Degradation Major Human Impacts on Marine Ecosystems and Coral Reefs Marine EcosystemsCoral Reefs Half of coastal wetlands lost to agriculture and urban development Ocean warming Over one-fifth of mangrove forests lost to agriculture, development, and shrimp farms since 1980 Soil erosion Rising ocean acidity Beaches eroding because of coastal development and rising sea levels Bleaching Algae growth from fertilizer runoff Ocean bottom habitats degraded by dredging and trawler fishing Increased UV exposure Rising sea levels At least 20% of coral reefs severely d amaged and 25–33% more threatened Damage from anchors Damage from fishing and diving

26. Fig. 8-14, p. 180 Chesapeake Bay The Chesapeake Bay is the largest estuary in the United States. However, the bay is severely degraded as a result of water pollution from point and nonpoint sources in six states and the District of Columbia, and from the atmospheric deposition of air pollutants.

27. The Chesapeake Bay—an Estuary in Trouble Human population increased Point and nonpoint sources raised pollution Phosphate and nitrate levels too high Excess sediments from runoff and decreased vegetation Oysters, a keystone species, greatly reduced 1983: Chesapeake Bay Program Integrated coastal management with local, state, federal governments and citizens’ group 2008 update: 25 years and $6 billion Program met only 21% of goals Water quality “very poor”