Deep dredging worsening lakes salinity levels


EAST Gippslanders will be pleased to hear that at long last a credible investigation into the increased salinity of the Gippsland Lakes was carried out by the Victorian EPA.

The EPA report presented in May 2013 clearly stated that the deepening of the entrance by Gippsland Ports was responsible for the increased salinity of the Gippsland Lakes.

Namely, “The Gippsland Lakes are characterised by a strong east to west salinity gradient corresponding to the increased influence of ocean waters. Salinity levels are driven by proximity to the entrance; and is produced by the salt water input at the entrance.”

The report further stated “The lakes have been modified, the entrance has been dredged even deeper, and this has had a profound modification. Increased salinity stimulates the release of dissolved nutrients from the lakes’ system” and “The high levels of surface water salinity threatens the surrounding freshwater swamps and wetlands.”

The report explains that the eastern lakes are generally salt stratified; (meaning a layer of freshwater over higher salinity bottom water) and that this condition is conducive to the release of nutrients from the lake’s sediment.

The released nutrients are then available to feed algal blooms.

It is disturbing that many old timers around the lakes have been saying precisely this since the entrance was deepened in March 2008 to facilitate the movement of deeper draft vessels servicing the offshore oil and gas platforms.

Freedom of information documents clearly demonstrate East Gippsland Shire Council operated as an agent for Gippsland Ports in applying for funding to investigate developing Lakes Entrance as a deep sea port to service the oil and gas platforms.

It is also interesting that in its application the council stated the entrance was 2.5 metres deep.

It is currently being maintained at six to seven metres deep; twice the depth that the previous dredge April Hamer could manage.

The lakes have now been invaded by marine species such as shark; stingray, squid, the European shore crab and a range of marine fish.

Sandworm are now dead, fringing vegetation has been killed and bank erosion has followed.

It is now time for the state and federal governments to step in and carry out an audit of the lakes’ ecological function, and commence urgent moves to establish a skills-based dedicated Gippsland Lakes Management Authority.

We have had enough of the spin designed to assure tourists that all is fine with the lakes’ health while they rapidly decline and take the tourist industry and the east Gippsland economy down with it.

There are practical solutions available to address the salt water intrusion of the lakes, but the problem appears to be that there are inadequate practical skills and experience at the top of government authorities.

For example, claims by the community that the deepened entrance is responsible for increased salinity was classified as a “myth”.

Some myth.