Estuaries and Coral Reefs

Chapters 3.4 and 3.5

Estuaries•Estuaries are formed where a

freshwater river empties into an ocean.

•The resulting water is brackish – a mixture of fresh and saltwater

•3 main types: 1. salt marsh or wetland, 2. mud flat or 3. mangrove swamp.

•May form what we call a bay.

Wetlands (Salt Marsh)

•May be protected by barrier beaches which were formed by the retreat of glaciers.–Barrier beaches protect the bay from ocean winds and waves. Ex. LBI, Seaside, Brigantine, Wildwood, etc.

•“Nurseries of the sea”

Wetlands (con’t)

•Grasses, like cordgrass, are specially adapted to the salt – glands that excrete salt

•Some marsh grasses actually filter pollution

•Crabs, fish, mussels, barnacles live here

Salt Marsh – Delaware Bay

Mudflats• “Graveyards of the sea”• Very stinky mud caused by bacteria

breaking down dead and decaying material and releasing SO2 – which smells like rotten eggs.

• Very rich, dark sand because there is little flushing (water moving in and out).

• This is where clams come from

Mudflat – Delaware Bay

Barrier Beaches of NJ

Mangroves

•Tropical bays and inlets covered by a thick growth of mangrove trees.–Red, white and black mangrove trees

•Prop roots stick above water during low tide.

Mangroves (con’t)

•Roots trap lots of nutrients making the mangroves a very rich environment

•Natural buffer to weather disasters

Mangrove

Coral Reefs•Contain more biodiversity of any

other marine ecosystems•Found 30 degrees North and 30

degrees South of the equator•Very sensitive to human influence

–Cloudy water, increased or decreased water temperature could kill the reef animals

Coral Reef – “Rainforests of the Sea” because of

biodiversity

Unique Adaptations of Reef Animals

• Camouflage• Color contrast – confuses predators• Disruptive coloration – breaks up

the outline of the fish• Territoriality

Camouflage

Color Contrast

Disruptive Coloration