Tropical Reefs

Most of the information below comes from the Website of Derek Keats.

Coralline Algae Link to Derek Keats Web Site

Nongeniculate Forms -> Reef Stability

They are the Most Abundant Organisms on the reef & they are Most Important for Reef Stability.

They Cement Coarse & Fine Grain Sediments into a solid substrata & are the Principal Reef Builders Porolithon_onkodesLab.jpg (84430 bytes)

They can withstand Desiccation at Full Sunlight

Maximum Abundance occurs in Shallow, Physically Disturbed Sites.

They Require Wave Shock & Grazing to prevent Overgrowth by other Fleshy Algae.

Some Corallines have the ability to Shed Surface Cells.

This Removes excessive amounts of Epiphytic organisms.

It also removes old, damaged parts of the Thallus.

This SEM image shows the process of Epithallial Shedding which removes excess Epiphytes

Encrusting coralline algae flourish where waves break on the reef, forming an elevated bank known as the Algal Ridge. As water from the waves returns seaward, its load of suspended sand and gravel scours a series of narrow ridges. The alternating ridges and valleys are known as spurs and grooves.

Corals growing on top of the spurs are stoutly formed and compressed in shape to withstand the extreme force of breaking waves.