Powlett River mouth closure provides habitat

Low river flows have allowed a sandbar to build up at the mouth of the Powlett River closing the river to the ocean.

West Gippsland Catchment Management Authority CEO, Martin Fuller, said the closure provides important habitat for plants and animals.

“Over the coming weeks, if the river mouth remains closed, we can expect to see water continue to cover the wetlands,” explained Mr Fuller

“This helps maintain the health of the wetland that surrounds the estuary”.

“The wetlands are a home to, and provide food for, many species of fish, birds and invertebrates.”

Mr Fuller said this natural process supports the wetland and animals living there.

“There is a flow on effect when the river mouth closes. Algae begins to grow which provides food for insects and fish.

“The calm waters then turn into a fish nursery and with the increase in fish and insects – birds come to feed.

“There are huge environmental benefits of the river mouth closing. An increase in freshwater river flows can create a natural opening. This will also trigger fish migration both upstream and out to sea,” explained Mr Fuller.

Mr Fuller said when the river mouth closes, monitoring begins to decide if an artificial opening should be attempted.

“Monitoring helps us stay on top of the conditions and allows us to find windows where safe openings might work,” explained Mr Fuller.

“This usually needs high river flows coming down the Powlett to help overcome Bass Strait’s powerful tides and oceans swells.

“Artificial openings under the wrong conditions can result in afish kill event or an immediate reclosure if there is not enough river flow to sustain an opening. “

Decisions to open the estuary mouth are informed by the Estuary Entrance Management Support System (EEMSS) and other information collected through monitoring and talking with stakeholders.

For more information about the Powlett River Mouth, the estuary and the closure visit www.wgcma.vic.gov.au.

Pied Cormorant at the Powlett River Estuary