Ocean Zones & Layers

1. Ocean Zones & Layers The ocean is divided into three zones across and three layers down. Use the diagram on the next slide to label the diagram on your paper!

2. Neritic Zone Intertidal Zone Open Ocean Zone Photosynthetic Layer 0-200m deep Continental Shelf Bathyal Layer 200-4000m deep Continental Slope Abyssal Layer 4000m - ocean floor Continental Rise

3. The Crazy Zone: Intertidal Zone Crazy Environment: Water level changes 4 times a day! Organisms must deal with extreme changes of: • Temperature • Drying out • Different levels of water, oxygen and light.

4. Intertidal Zone • Tide Pools are an ecosystem in the Intertidal Zone. • Biodiversity is very high in tide pools. There are many different species in 1 small area.

5. Advantages of Living in a Tidepool • Lots of O2 and sunlight • Currents and tides mix the water to take away waste and bring in new nutrients • Lots of nutrients • Rocks for shelter • There are few large carnivores, so less predators are there to eat you • Rich food sources

6. Challenges of Living in a Tidepool Desiccation = drying out. • Organisms need to be able to breathe in and out of water

7. How do you survive Tidepool Living? Olive Snail • One way is to move between tidepools, like hermit crabs do. • Olive Snail: burrows into moist sand.(Sand dollars, clams and worms do this too) • Limpet: Dig a hole in the rock – traps water, and protects animal from waves Limpet

8. How do you survive tidepool living? • Use Cracks:Organisms can crawl into these protected areas. Protects the animal from waves and each other. • Rockweed:This plant can lose up to 90% water and still survive! Crab

9. How do you survive tide pool living? *Barnacles: Close their shells to reduce evaporation *Sea Anemones: withdraws into itself and covers itself with a thick outer skin (http://www.youtube.com/watch?v=ctqvqES1PE8)

10. How do tidepool organisms deal with extremes in temperature? • Snails: have light colored shells to reflect sunlight and absorb less heat • sea anemones: Decrease the surface area of their body (shrink up) to decrease evaporation of water

11. How do tidepool organisms deal with Wave Action? • Waves pound the shore and can damage fragile organisms. • Olive Snail: Buries into sand • Barnacles: Clamp onto rock, streamlined shape, armored from wave energy • Chiton: clings to rock with suction cup/muscular foot

12. Deal with Wave Action… • Starfish: have suction cups to stick to rocks, but they don’t work on sand • Sea Palm: Plant that is flexible and streamlined, so it can take the beating of waves. Sea Star

13. Zone Two: The Neritic Zone • This is the area from the shoreline to the edge of the continental shelf.

14. Challenges in the Neritic Zone: • Turbulent wave action • Depths, temperature, etc. will be affected by the tides. • High levels of UV radiation • Currents effect habitat

15. Neritic Zone • Realize, the neritic zone changes based on the season, climate & location. • This zone is influenced by the land around it. River run-off and sediment cycles lead to different amounts of minerals in the water. The surface of the ocean constantly has access during the day to sun, deeper areas only receive sunlight when the sun is overhead.

16. Animal life in the Neritic Zone: Many different types, sizes, species.

17. Types of Animals in the Neritic Zone Plankton • Plankton = Floating animal (usually one to a few cells) • Nekton = Swimming, maneuvering animals (fish, sharks, seals, etc.) • Benthos = Bottom dweller (on or in the ground) Nekton Benthos (ex. Halibut)

18. Zone 3: The Open Ocean Zone • This is the rest of the ocean from the continental slope out. • Plants & Animals change a lot depending on what layer of the open ocean they live in. • Open Ocean Layers: Layers going down through the depth of the ocean (Photosynthetic, Bathyl & Abyssal)

19. Open Ocean ~ Photosynthetic Layer: • This is the top 200 meters of the ocean across the entire ocean. • This is the area that receives sunlight, so it is the only area that plants & algae can exist.

20. Open Ocean ~ Photosynthetic Layer Benefits to living here are: • Warmer water • Low pressure • More nutrients, food and plants. Challenges are: • More competition & danger • Have to deal with water movement (waves, tides & currents) • UV Radiation and some temperature changes.

21. Open Ocean ~ Bathyal Layer: • This is the area from 200 meters to 4000 meters deep. • Light doesn’t reach into this area, so there are less animals and NO plant life.

22. Open Ocean ~ Bathyl Layer Benefits to living in the Bathyal Layer: • Less competition • Easier to hide in darkness from predators Challenges to living in the Bathyal Layer: • It’s Dark! • High pressure (increases with depth) • Always very cold (but at least the temperature is constant)

23. Open Ocean ~ Abyssal Layer: • Area from 4000 meters to the bottom, also known as “The Deep” • There is NO light here and VERY few animals live here. • These animals are WEIRD, with strange adaptations to living in such a cold, dark place

24. Open Ocean ~ The Abyssal Layer Benefits to living in the Abyss: • Less predation & competition (because not much lives here) • Uniform temperature & salinity Challenges to living in the Abyss: • Extreme pressure • Low nutrients • No light & cold temperatures • Low numbers of living things (so finding a mate/food is hard)

25. Along the ocean floor we see these land features: • Abyssal Plains = Flat sea floor • Trench = A valley. These are carved out by water currents.

26. Ocean land features • Mid-Ocean Ridge – in the middle of the ocean floor = a continuous mountain range that winds around Earth under the ocean waters.

27. On the ocean floor we also see Hydrothermal Vents! • HTV’s are cracks in the Earth’s crust that spew hot water (up to 350 °F!). • The water is heated by magma under the sea floor. • Only bacteria can live in this water. • Interesting because the bacteria do “chemosynthesis” by changing sulfur in the hot water into food energy (instead of photosynthesis, which changes sunlight into food)