Brightly coloured and composed of a huge range of invertebrate species, sponge gardens are found growing on deep reefs (generally greater than 20m) along the coast of Victoria. These habitats flourish in deeper waters or shaded areas because they do not require much light, unlike algae and seagrass.
The invertebrates which make up the fascinating ecosystem include sponges, hydroids, sea fans, sea whips, sea pens, tube worms, bryozoans and ascidians. These, in turn, provide an important habitat for other animals (e.g. nudibranchs).
The invertebrates which make up sponge gardens are generally filter feeders, which means that they filter small particles out of the water column for food. Sponge gardens play an essential role in nutrient cycling in the ocean.
- Fishing or removal of animals and plants
- Marine pests such as the Northern Pacific Seastar (Asterias amurensis) or the Japanese Kelp (Undaria pinnatifida) which compete for food or space
- Anchor damage
- Climate change effects including sea level rise, warming sea surface temperatures, and increasing ocean acidity.
Where to see sponge gardens
- Wilsons Promontory Marine National Park
- Port Phillip Heads Marine National Park
- Bunurong Marine National Park
- Twelve Apostles Marine National Park
- The Arches Marine Sanctuary
- Beware Reef Marine Sanctuary