1. Marine Habitats

2. Estuaries
Definition: fresh water from a river mixes with salt water from the ocean
-Transition area from the land to the ocean
Other names: bay, sound, lagoon, harbor, bayou
Ocean
Area where fresh and salt water mix
River bringing freshwater to the sea

3. Characteristics of Estuaries
Water is brackish: a mixture of freshwater and saltwater
There is a gradient (gradual change) in the salinity

4. Characteristics: Estuaries
-Very nutrient rich ecosystems  leads to high productivity and high biodiversity
-Fast-moving rivers and waves carry nutrient-rich particles
-Sediment settles and accumulates
-Great place for plants to grow!

5. -Buffers land from hurricanes, absorb storm surge

6. Estuary Have a large variety of species. eelgrass cordgrass
glasswort – a succulent

7. Estuary animals
Including… horseshoe crabs
Mosquito…

8. Estuary animals
oysters
lobster

9. Estuary animals
Flounder
Striped Bass

10. Estuary animals
Many, many birds!
Common tern
Great White Egret

11. Estuary animals
Manatee

12. Estuary animals
Sea lions at Pier 39 in San Francisco Bay

13. Salt Marshes -Low area that is subject to regular, but gentle, tides
-Dominated by grasses (no trees or shrubs)
Location: Gulf of
Mexico and
Atlantic coast
Texas salt marsh

14. Alabama salt marsh
Dauphin Island, AL

15. Mangrove Swamps
-Coastal wetlands located in tropical and subtropical zones
-Characterized by salt-tolerant trees and shrubs, such as mangrove trees

16. Mangroves

17. Rocky shores
-Also called rocky intertidal zone – many places to live in this habitat, means high biodiversity
-Organisms must be adapted to wave action, changing tide levels

18. Rocky Shores
At low tides, there are often tide pools left behind where you can see starfish, anemones, crabs, octopus

19. Sandy shores

20. Sandy Shores Not as much biodiversity as rocky shores – Why?
not much habitat diversity
sand dries out at low tide
some small things can live in the sand, food for shorebirds

21. Barrier Islands
-Narrow islands made of sand that provide a buffer for the mainland from the sea
-Constantly shifting, especially with storms
Ex: Dauphin Island, Alabama

22. Barrier Islands Ocean Beach Intensive recreation, no building
Primary Dune
No direct
passage
or building
Trough
Limited
recreation
and walkways
Secondary Dune
No direct
passage
or building
Back Dune
Most suitable
for development
Bay or
Lagoon
Intensive
recreation
Bay shore
No filling
Grasses or shrubs
Taller shrubs
Taller shrubs and trees
Think about ecological succession as you move away from the ocean. What is the “disturbance” in this ecosystem?

24. Notice the beach erosion. Barrier islands are constantly changing.

25. Coral Reefs
Structures in the shallow oceans that are built by animals called corals
Serve a habitat for many diverse organisms
Require two things: warm temperatures and sunlight
Found between 30°N and 30°S of the equator

26. Coral Reefs Corals are animals
Coral polyps resemble small sea anemones with tentacles that can sting and paralyze prey

27. Coral Reefs -They build limestone houses that build up to form a reef.
Polyps in limestone skeleton
Elkhorn coral

28. Coral Reefs
-Corals live in a symbiotic relationship with algae called zooxanthellae;
-The algae are photosynthetic and give the coral food and oxygen
-The algae get carbon dioxide and nutrients from the nitrogenous wastes of the coral

29. Coral Reefs There are many different kinds of corals: Soft corals
Hard corals

30. Coral Reefs
Growing on the reef with the corals are other animals, such as sponges, worms, shrimps, crabs, mollusks
Living in and around the reef are fish, sea turtles, sea snakes, marine mammals

31. Coral Reef Destruction
Coral bleaching – when temperatures go above normal, the zooxanthellae can’t thrive, the coral turns a whitish color and dies
Natural causes: El Nino
Manmade causes: Global warming

32. Coral Reef Destruction
2. Physical damage
Ships, anchors, tourist divers
Dynamite fishing - reefs are damaged by physical destruction that may occur when people collect fish

33. Coral Reef Destruction
Land development and pollution – loss of mangrove forests means more nutrients and sediments flow out to the sea; coral may die from sediment or algal blooms
Fish and coral trade
Increased
exposure to UV
due to ozone
depletion

34. Hydrothermal Vents (review)
-Water sinks into fissures.
-Releases some nutrients and dissovles others.
-Nutrients are used to support life on the ocean floor.

35. Kelp Forest Kelp is large brown algae (Seaweed)
Provides rich habitat for species
Will grow as deep as photosynthesis reaches.

36. Kelp Forest Kelp are found in nutrient rich and cold water.
Found on the western coast of continents due to polar currents and upwelling of nutrients.