News and updates

Possible algal blooms in Port Phillip Bay

6 Jan 2017

Environment Protection Authority Victoria (EPA) is advising of possible algal blooms in Port Phillip Bay and fish deaths elsewhere in the state following the recent heavy rain.

Last week’s storms flushed a large amount of organic pollution into Victoria’s catchments and Port Phillip Bay, causing many beaches to experience poor water quality.

While water quality at most beaches has now returned to normal, the increase in nutrients in the water could lead to algal blooms, particularly along the eastern shores of Port Phillip Bay.

A nutrient-rich plume of stormwater runoff has been flowing from the mouth of the Yarra River into Port Phillip Bay since late December.

With calm and warming conditions predicted for the coming days, EPA advises that the community may start to see visible algae blooms.

While marine algae occur naturally and are present year-round in all marine waters, including Port Phillip Bay, some people may experience skin irritation after contact.

EPA advises people to avoid contact with any water that looks murky or discoloured.

The increase in organic matter that has been flushed into Victoria’s rivers, tributaries and lakes following the heavy rain may also lead to fish deaths from blackwater events over the coming days.

Blackwater events usually result in the dark appearance of water due to the release of dissolved carbon compounds as organic matter breaks down.

They’re also often accompanied by an unpleasant odour as microbes in the water break down the material into inorganic compounds and carbon dioxide. 

While normal amounts of organic material can be broken down naturally, when too much organic material is released into the water, the microbes use up oxygen more rapidly than it can replaced from the air above, causing fish to be starved of oxygen.

Members of the public are encouraged to report suspected fish deaths or pollution to EPA’s hotline by calling 1300 372 842 (1300 EPA VIC).

EPA investigates reported fish deaths and works closely with the Department of Environment, Land, Water and Planning (DELWP), water corporations and catchment management authorities to manage fish death events.

Page last updated on 6 Jan 2017