In Port Phillip Bay, large expanses of seagrass meadows are found in shallow waters protected from prevailing westerly winds and waves. These areas include Swan Bay, Corio Bay, parts of the southern shore of the Geelong Arm, and the Bellarine Bank, which is located offshore between Clifton Springs and Point Richards, Portarlington.

Seagrass meadows are a vital part of the marine ecosystem due to their high productivity. The Bellarine Bank has been shown to be an especially important habitat in the life cycle of King George Whiting, with each hectare of seagrass supporting up to 30,000 juvenile whiting (ref. Mapping Ocean Wealth).

Living seagrass meadows perform many functions:

• stabilising the seabed
• storing carbon
• providing food and habitat for other marine life
• providing nursery areas for juvenile fish and invertebrates (i.e. animals without backbones such as snails, crabs and worms)
• maintaining water quality
• are an indicator of a 'healthy' marine ecosystem.

Detritus from the breakdown of dead seagrass plants provides food for worms, sea cucumbers, crabs, and filter feeders such as anemones and sea squirts (ascidians). Further decomposition releases nutrients (such as nitrogen and phosphorus) which, when dissolved in water, are re-absorbed by seagrasses and phytoplankton (microscopic plants).

When seagrass and algae (seaweed) wash up on the beach, the thick layer of natural material becomes habitat for a range of animal species that are essential to a healthy beach ecology. Seagrass wrack provides food and shelter for scavengers such as amphipods (sandhoppers) and other invertebrates that consume the debris. Amphipods are a main source of food for shorebirds including waders such as the red-necked stint, that forage in exposed seagrass wrack. When covered by tides, the animal life in the wrack become a food source for fish.

Accumulated seagrass wrack can assist in stabilising eroding beaches by providing a substrate on which sand and other sediments can accumulate. Additionally, local coastal plant species are known to readily recolonise stranded wrack.

Given the ecological values of the beach washed wrack, responsible coastal management agencies have identified the importance of maintaining the natural decomposition processes to ensure healthy food webs to support our broader marine communities and users (for example: fishers, beach walkers and birdwatchers).