FLORIDA COASTAL PRIMARY SUCCESSION:From sand and water to

Mangrove island formation

Rosa Whiting, MPH

Littoral zone - top zone, warmest, shallow and can absorb more of the Sun’s heat. Many algae (like diatoms), rooted and floating plants, snails, clams, insects, fishes, crustaceans, and amphibians, dragonflies, midges, the egg and larvae stages are found here. Turtles, snakes, and ducks find much food here!

FRESH WATER ECOSYSTEM:

INTERTIDAL ZONE - submerged and exposed to waves and tides.  Waves keep mud and sand constantly moving, thus very few algae and plants can establish themselves. The communities are constantly changing: - upper area: algae and small animals, such as herbivorous snails, crabs, sea stars, small fishes, worms, clams, crabs, shorebirds. - bottom: exposed during the lowest tides, many invertebrates, fishes, and seaweed; on sandier shores--not as stratified as in rocky areas.  

MARINE ECOSYSTEM:

Soil development in intertidal zones:Sand (particulates of shells and rocks) plus waterVery little wave actionBacteria & protists that fill the water live, die, sink to

bottom of seabedAlgae such as Grasselaria take root in the new “soil”Sea grasses can start living in areas when more nutrients

are available from organic materialEel/shoal grass (Syringonium)Manatee grassTurtle grass

Mangroves begin to take rootRedBlackWhiteButtonbush

Primary marine coastal succession begins with bare sand covered by shallow water. Pioneer organisms begin to accumulate.

MicroscopicPIONEER ORGANISMS:BacteriaProtists – diatoms and dinoflagellates

Phaeophyta

The brown algae are almost exclusively marine and are very common in the coastal waters of Florida. Many are very large in size, as the kelps of the Pacific coast. Brown algae have walls containing cellulose and chloroplasts with chlorophylls a and c. They often store their sugars as laminarin. The most common brown alga in South Florida is Sargasso (Sargassum sp.), which is commonly left on our beaches after high tide. Sargasso is very similar to the related Fucus, which is common to New England coasts. Here is a diagram of Sargasso, showing the blades and flotation bladders. The life cycle of Fucus is very similar to ours in that the only haploid cells are the sexual gametes; it is almost identical to that of Sargasso.

Sargasso(Sargassum filipendula)

Here are some other brown algae, quite commonly seen on rock reefs and mangrove areas in south Florida.

Ectocarpus

Stypopodium Turbinaria

Multicellular algae begins to take hold:

Sea Grasses begin to grab a foothold:Eel or Shoal grass (Halodule wrightii)

Turtle grass (Thalassia testudinum)

Manatee grass (Syringodium filiforme)

Widgeon grass (Ruppia maritima) grows in both fresh and salt water and is widely distributed throughout Florida's estuaries in less saline areas, particularly in inlets along the Florida east coast.

Mangroves arrive in succession:Red: has prop roots (drop roots)Black: has snorkel roots

(pneumatospores); filter saltWhite: has 2 salt glands at base of leafButtonbush – we do not have around here

Red mangrove seeds float, already sprouted and ready to take root!

Red Mangrove - Rhizophora mangle

Black Mangroves have snorkel roots or pneumatophores:

Black Mangrove – Avicennia germinans

White mangrove: smallest seed, last to inhabit a new area

Two salt glands at baseof leaf

Propagule or seed

White Mangrove – Laguncularia racemosa

ButtonbushCephalanthus occidentalis