Coral Reef Plants

On healthy reefs, coral reef plants are inconspicuous and appear heavily outnumbered by an abundance of animal life (see photo, below right).

This is in stark contrast to familiar terrestrial ecosystems such as forests, prairies, jungles, etc. which are invariably heavily dominated by the abundant plant life that forms the base of their food chains.

Where then, on coral reefs, is the plant life that ultimately must provide nutritional support for all those corals, fishes, and other animals that occupy coral reef ecosystems?

In truth, plant life is actually abundant and widely distributed in coral reef ecosystems. But unlike animal life, the presence of plant life can only really be appreciated by looking at the coral reef biome at macro (ecosystem) and micro-scale levels.

Types of Plants Found in Coral Reef Ecosystems

There are three very different types of plants widely associated with coral reef ecosystems: marine algae, seagrasses, and mangroves.

A. Marine Algae

A variety of forms of marine algae are always present in coral reef ecosystems; in fact, a few types are essentail to the survival of corals and the formation of coral reefs.

Within the two coral reef zones where most hard coral growth is found (the fore reef and reef crest), plant life exists only in the form of marine algae.

Most of this algal growth exists in the form of tiny microalgae. Macroalgae is also present, but is a relatively minor component of healthy reefs in terms of biomass.

The singular exception to this generality are the coralline algae, a specialized type of macroscopic red algae that actually helps build coral reefs and is a generally present in considerable amounts.

B. Seagrasses

Seagrass meadows are extensive and abundant in many coral reef systems. Like mangroves, the distribution of seagrssses is restricted to the protected waters of the back reef (lagoon) zone, where they form a distinctive habitat-type that supports a broad diversity of other forms of marine animal and plant life.

C. Mangroves

Mangroves are shoreline plants, and thus are often (except on fringing reefs) quite distant from the main biomass of hard corals that form the massive reef crest and fore reef. However, when present these plants have the capacity to considerably enhance the abundance and diversity of marine life throughout the coral reef ecosystem.

Summary

Coral reef plants are in truth omnipresent in coral reef ecosystems, but it is only within the shallow, sheltered back reef zone do we find two kinds of obvious plant-dominated habitat-types (mangrove forests and seagrass meadows) of the size and extent that we associate with those that characterize most terrestrial ecosystems.

Each of the three main kinds of plants found in coral reef ecosystems (and briefly introduced here) is discussed in greater depth on separate pages of our web site. Because of their prominance as coral reef plants, an entire page is devoted to coral reef algae.

A more thorough discussion of mangrove forests and seagrass meadows as coral reef habitats is provided on our page on the "back reef" (see "Related Pages", below).

An ecosystem-scale perspective on the respective contributions of coral reef plants of all three types to overall energy production and nutritional support of the coral reef community is discussed in greater detail in our section on the coral reef food web.

Related Pages

Coral Reef Algae The distribution, characteristics and ecological roles of marine algae in coral reef ecosystems

Seagrasses and Mangroves (Back Reef page)
The physical characteristics, distribution and ecological role of seagrasses in coral reef ecosystems