Seagrasses of Western Australia.
Western Australia boasts an enormous coastline of some 12,500 km, including
waters ranging from temperate to tropical. The southern coastline borders
the Southern Ocean at latitudes of 32-34°S; the northern coastline
is on the Timor Sea from 12-15°S, while the remainder borders the
Indian Ocean. A wide variety of conditions exists along this coastline,
which includes large areas of shallow soft seabed which form an ideal
habitat for seagrasses. The map below shows the Western Australian coastline;
seagrass habitats are highlighted in blue. (Source: Kirkman
& Walker, 1989.)
Seagrasses cover an estimated 20,000 km² of inshore seabed, and make up an important component of the coastal ecosystem in Western Australia (Kirkman & Walker, 1989). Major areas of seagrass growth are sheltered embayments and estuaries, although extensive meadows also occur in more exposed locations. The large, calm, shallow expanse of Shark Bay (13,000 km² contains some 12 species of seagrasses, which cover an estimated 4,500 km² of seabed - the largest reported seagrass meadows in the world (Walker, 1989).
Some 26 species of seagrasses in 10 genera are to be found in Western Australian waters (Kirkman & Walker, 1989), a record unequalled anywhere in the world (Walker & Prince, 1987). Clicking on a name in the list below will (eventually) provide details and an image of that species as well as a distribution map for Western Australia.
A useful source of angiosperm phylogenetic information (which includes seagrasses) is:
Note that Stevens has used different synonyms for the orders listed below (i.e. he has placed them all in the Alismatales).
Division: Magnoliophyta (= Anthophyta) Cronquist, Takhtajan &