1. Aquatic Ecosystems Wednesday, November 1st Reminder: Problem Set due Friday!

2. Aquatic Ecosystems Oceans Lakes Streams and Rivers Estuaries Freshwater wetlands

3. Some General Questions:  Where does the energy to support aquatic life come from?  How productive are each of the aquatic environments?  What is the limiting factor in each aquatic environments?  How have humans changed these environments?

4. The open ocean is most like… A) a tropical rain forest B) the boreal forest C) the desert D) chaparral … with regard to productivity.

5. Net Primary Productivity (NPP) by Biome

6. Coastal Upwelling

7. Atmospheric/Ocean Coupling surface currents are driven by wind

8. Ocean: surface currents

9. Where is the ocean most productive? Where nutrients are available:  near the coast From upwelling rivers bring nutrients  Polar upwelling –Short, intense productivity Where sunlight is available: Top 100 meters (euphotic zone)

10. Ocean Primary Productivity

11. Coastal Upwelling Most upwelling occurs in response to longshore winds. Upwelling: increased nutrients, increased primary production good fishing! El Nino brings warm water, shuts down upwelling, bad for fisheries

12. Is Primary Production always good for upper trophic levels? Harmful algal blooms: toxicity or increase in BOD suffocation, starvation Red tide

13. Kelp forest ecosystem 30-40 m water depth Determined by light availability Require high concentrations of nutrients Occur mostly in areas of upwelling Provide primary production (food) and habitat!

14. Kelp forest ecosystem Kelp provides otter habitatSea urchins eat kelp Otters eat sea urchins

15. Kelp forest ecosystem

16. Kelp Forest Food Web

17. Kelp Dampens Waves

19. Impact of Kelp Deforestation on Low Productivity Terrestrial Env’ts Example: Channel Islands Kelp detritus = nutrient input to intertidal communities Marine bird and mammals feed on intertidal organisms Feces/guano provide nutrients to terrestrial organisms Biggest impact where ratio of shoreline to area is high

20. Coral reefs  Coral reefs are extremely productive  Visibility is great!  But we know that nutrient-rich water is murky How is this possible? Where are the nutrients? What terrestrial biome does this remind you of?

21. Coral reefs  Efficient cycling of nutrients  Complex relationships between organisms Corals: plants or animals? zooxanthellae in coral intricate food webs

22. Rocky Intertidal Zonation

23. Selective Pressures in Intertidal Zones TidesSalinity Waves

24. Summary  Oceans Productivity: euphotic zone/thermocline/nutrients/BOD/algal blooms Open ocean vs. coast –Nutrients: upwelling and coastal inputs Kelp Forest (keystone species: sea otter) Coral Reefs (zooanthellae, coral bleaching, dynamite fishing)  Rocky Intertidal Zonation and adaptations