Download Neptune Seagrass

BIOSNIPPET
ISSUE 19
Scientific Name:
Posidonia oceanica
English:
Neptune Seagrass,
Posidonia
Maltese:
l-alka, l-alka l-kbira,
il-posidonja
This is a flowering seagrass species endemic to the Mediterranean Sea. It
is an herbaceous perennial that occurs submerged in seawater at depths
ranging 1-50m, occasionally more, forming large extents called Neptune
seagrass meadows or beds. The name Posidonia was termed after the
Greek god of the sea Poseidon; this is also reflected in the English name,
where Neptune is the Roman god of the sea. The term oceanica refers to its
marine occurrence and its former wide distribution. Its long ribbon-like, green
leaves turn brown with age. Under these leaves are fibrous tufts which are
essentially the remains of dead leaves. These tufts are packed by the rolling
action of waves and form rounded structures known as Neptune Balls, and
eventually end up washed ashore. In spring, green and inconspicuous flowers
are borne on stout stalks, which upon fertilisation form olive-shaped fruit,
which are sometimes also found on beaches and shores.
Posidonia meadows provide a vital marine habitat, which apart from
providing food and shelter for numerous invertebrates, fish and other marine
vertebrate species like turtles, are also an important breeding ground, and
are considered as an effective natural means against coastal wave erosion.
Furthermore, strong currents often detach Posidonia leaves; these are most
often deposited on seashores by wave action, forming mounds on sandy
beaches. In turn, these mounds support a vast array of terrestrial and marine
creatures, such as amphipods, isopods, snails, and others.
The Neptune Seagrass and Posidonia meadows are considered to be a
priority habitat of importance at European level and are protected both at
regional and local level.
Environment and Resources Authority
Hexagon House, Spencer Hill Marsa MRS 1441 T: (+356) 2292 3500 E: [email protected] W: era.org.mt