This document describes several types of marine ecosystems: estuaries, salt marshes, mangrove swamps, rocky shores, sandy shores, barrier islands, and coral reefs. Estuaries are transition areas where fresh water from rivers mixes with salt water from the ocean, creating very nutrient-rich environments that support a high diversity of plants like eelgrass and cordgrass, and animals including blue crabs, fish, birds, and mammals. Coral reefs are structures built by corals in warm, sunlit, shallow ocean waters that provide habitat for numerous species.

1. Marine
and Fresh
Water

2. Marine
Ecosystem

3. Marine
Ecosystems

4. Types of Marine
Ecosystems
 Estuaries
 Salt marshes
 Rocky shores
 Sandy Shores
 Coral reef
 Mangrove swamp
 Barrier islands

5. Estuaries
An area in which fresh water from a river mixes
with salt water from the ocean; a transition area
from the land to the ocean. Other names: bay,
sound, lagoon, harbor, or bayou.
The Ocean
Area where
fresh and salt
water mix
River bringing
freshwater to
the sea

6. Characteristics of
Estuaries
 Very nutrient rich ecosystems  leads to
high productivity and high biodiversity.
 Fast-moving rivers and waves carry
nutrient-rich particles.
 Sediment settles out in the estuary when
the water slows down.
 Nutrients accumulates on the bottom
(benthic zone).
 Great place for plants to grow!

7. Estuary plants
Plants must be adapted to salty habitat
eelgrass
cordgrass
glasswort – a succulent

8. Estuary animals
Huge variety including…
Blue crab, Stone crab, Fiddler crab,
Horseshoe crab, Mosquito, Lobster,
Flounder, Stripped bass, Crane,
Flamingo, Sea gull, Ibis, Manatee,
otters, and many more.

9. Salt Marshes
 A low area that is subject to regular, but gentle,
tides, dominated by grasses.
 Salt marshes do not have trees or shrubs
Texas salt marsh

10. Mangrov
e
Swamps
Coastal wetlands
located in tropical
and subtropical
zones; characterized
by salt-tolerant trees
and shrubs, such as
mangrove trees

11. 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

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

13. Sandy Shores
Sandy shores or beaches are loose deposits of
sand, gravel or shells that cover the shoreline
in many places. They make up two-thirds of the
world’s ice-free coastlines.

14. Barrier Islands
A long, narrow, offshore
island, usually having
beaches and dunes on
the seaward side,often
with lagoons on the
landward side

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

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