State of the Reef Report 2008: Macroalgae (Seaweeds)

Abstract

Macroalgae is a collective term used for seaweeds and other benthic (attached to the bottom) marine algae that are generally visible to the naked eye. Larger macroalgae are also referred to as seaweeds, although they are not really “weeds”. In this report, macroalgae are treated as marine plants because they are photosynthetic (convert sunlight into food) and have similar ecological roles to other plants. However, macroalgae differ from other marine plants such as seagrasses and mangroves in that macroalgae lack roots, leafy shoots, flowers, and vascular tissues. They are distinguished from microalgae (e.g. diatoms, phytoplankton, and the zooxanthellae that live in coral tissue), which require a microscope to be observed.