1. Chapter 7-2
Marine Ecosystems

2. Marine ecosystems
Coastal areas –
Open ocean -

3. Coastal Wetlands
Areas that are covered by salt water for all or part of the time are known as coastal wetlands.
Provide habitat and nesting areas for many fish and wildlife.

4. Coastal Wetlands

5. ESTUARIES
Estuary: an area where fresh water from rivers mixes with salt water from the ocean.

6. ESTUARIES

7. Plants and Animals of Estuaries
High primary productivity supports many consumers
Large populations of rooted plants as well as plankton.
Plankton provide food for fish - can then be eaten by larger animals such as dolphins, sharks, etc.
Oysters and clams anchored to rocks filter feeding

8. Plants and Animals of Estuaries
Organisms must be able to tolerate variations in salinity
Daily tides and river flow

10. Estuaries in populated areas were often used as places to dump waste.
Threats to estuaries
Estuaries in populated areas were often used as places to dump waste.
Estuaries filled with waste could then be used as building sites.
Pollutants such as raw sewage, pesticides, fertilizers, and toxic chemicals.

11. Salt marshes Salt marshes:
found primarily throughout the temperate and subarctic regions.

12. Salt marshes
Supports a community of clams, fish, aquatic birds, crabs, and shrimp.
Can absorb pollutants and storm surges to help protect inland areas.

13. Mangrove Swamps
Mangrove swamps:

14. Mangrove Swamps
Protect the coastline from erosion and reduce the damage from storms.
Provide a home and breeding area for about 2,000 animal species.
Have been filled with waste and destroyed for coastal development in many parts of the world.

15. Rocky and Sandy Shores
Rocky shores have many more plants and animals than sandy shores do
Sandy shores dry out when the tide goes out

16. Rocky and Sandy Shores
Barrier island:

17. Coral Reefs
Coral reefs form in clear, warm coastal waters in tropical areas
Tiny animals (polyps) and algae have a mutualistic relationship
Polyps secrete calcium carbonate shells, which become coral reefs

18. Coral Reefs
Thousands of species of plants and animals live in the cracks and crevices of coral reefs – one of the most diverse ecosystems on Earth.
Corals are predators that use stinging tentacles to capture small animals, such as zooplankton, that float or swim close to the reef.

19. Coral Reefs

20. Coral Reefs

21. Coral Reefs
Vulnerable to damage
Warmer ocean temperatures leading to coral bleaching
Coral expels algae and thus the polyps can die
Increasing ocean acidity
Direct destruction – boating, fishing techniques (trawling)
Deposition of Sediment
Algal Blooms

22. Coral Reefs

23. Oceans
Water absorbs light, so enough sunlight for photosynthesis penetrates only about 100 m into the ocean.
Ocean’s life is concentrated in the shallow coastal waters where sunlight penetrates to the bottom and rivers wash nutrients from the land.

24. Plants and animals of the Ocean
In the open ocean, phytoplankton grow only in areas where there is enough light and nutrients, resulting in one of the least productive of all ecosystems.
Fish feed on the plankton as do marine mammals such as whales.

25. Three vertical zones of the open sea
Euphotic zone (top zone)
Bathyal zone (middle zone)

26. Three vertical zones of the open sea
Abyssal zone
Dark and cold
NPP low in the open sea
Except in upwelling areas

27. Euphotic Zone Bathyal Zone
High tide
Coastal Zone
Open Sea
Low tide
Depth in meters
Sea level
Photosynthesis
Euphotic Zone
Estuarine Zone
Continental shelf
Bathyal Zone
Twilight
Water temperature drops rapidly between the euphotic zone and the abyssal zone in an area called the thermocline.
Abyssal Zone
Figure 8.6: This diagram illustrates the major life zones and vertical zones (not drawn to scale) in an ocean. Actual depths of zones may vary. 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? (Hint: see Figure 7-14, p. 157.)
Darkness
Water temperature (°C)
Fig. 8-6, p. 171