This article outlines some important functions of seagrasses and some aspects concerned with the distribution, biology and ecology of the New South Wales seagrasses.
Plants of the marine environment can be separated into a number of categories. The most basic division considers whether or not the plant is an angiosperm – the so-called ‘higher’ plants which produce flowers and have a greater structural complexity than the algae. Marine angiosperms are more commonly referred to as seagrasses and, although they are all monocotyledons, they are related only in appearance to the terrestrial grasses. Seagrasses generally inhabit soft sediments, from sand to mud, within sheltered shallow waters of estuaries, bays, lagoons and lakes.
World-wide there are about fifty-two species of seagrasses. Twenty-five of these occur in Australian waters, and six are found in the New South Wales coastline. These are Posidonia australis, Zostera capricorni, Zostera muelleri, Heterozostera tasmanica, Haliphilia ovalis, and Halophilia decipiens. Seagrasses are strictly defined as angiosperms which are able to complete their life cycle in seawater. This definition excludes another genus of aquatic angiosperms which will be treated in this review (Ruppia). This genus, which is more often found in brackish waters, has three species in New South Wales, Ruppia maritima, Ruppia megacarpa and Ruppia polycarpa. The latter two species have water-surface pollination and are thus usually restricted to shallow, still waters. Ruppia species are also sometimes found in non-marine brackish waters (Sainty and Jacobs 1981).
How to Cite:
West, R.J., 2010. The seagrasses of New South Wales estuaries and embayments. Wetlands Australia, 3(1), pp.34–44. DOI: http://doi.org/10.31646/wa.69