Sponges live at all depths of the ocean from intertidal habitats to depths of up to seven kilometres. In Port Phillip, they colonise selected areas in large numbers and produce a colourful array of oddly shaped forms, from branched projections to globular and near perfectly rounded balls. Some species are important reef-building organisms, attaching to rocks or encrusting hard surfaces. Many also live in sediments and play an important role in consolidating the sand, shell grit or mud to form anchors for their own growth as well as for a host of other organisms found in these habitats.
Sponge gardens habitat video
At the southern end of the bay, the increased currents carry lots of nutrients and plankton, and these form the food of the filter feeding animals like sponges, sea squirts and scallops. In these areas these beautiful sponge gardens form.