Red swimmer crab, (Nectocarcinus integrifrons) very common in SA; Lives in seagrass beds. Also See information here about European Shore Crab (another recent import).

July 26 2010: More invaders into the lakes. Fishermen caught more of them last night near Metung. A Leopard shark was also caught by him in this area, but in one of the channels closer to the coast. As he has been fishing the lakes all of his life and has never seen these crabs before, I suppose the question now is when did they arrive and how the hell did they get here.

The mouth at Lakes Entrance, constant dredging is allowing vast quantities of sea water into the Lakes System

Some interesting quotes from a long buried report

Royal Society of Victoria Proceedings Vol 91 & 92 9 March 1981

11 TIDAL SCOUR IN THE GIPPSLAND LAKES by Geoffrey King

"The opening of the artificial entrance in June 1889 made a permanent connection with the sea and subjected the Lakes to greater tidal influence. The most immediate effect must have been an increase in salinity followed by major ecological changes...The flood flow however entered the system as a dense saline wedge creating bottom currents well into the Lakes system...The intrusion of the sea into the Lakes began with an unexpected breakthrough by storm waves in June 1889. This completed the artificial cut in the barrier that had begun nearly 20 years prior. Tidal currents quickly scoured the entrance to a navigable depth and Reeves Channel became a tidal channel through which ebb and flood currents moved in response to the tidal level at the entrance. The 12km meandering passage into the main body of the Lakes was a significant constriction to the tidal flow and tidal levels in Lake King were greatly diminished relative to the entrance....In terms of the salinity pattern, the Lakes can be classified as a mixed estuary (Drake 1976) i.e. a nett landward flow of saline water and a seaward flow of less saline lake water. The degree of saline intrusion is determined by the fresh water head relative to the tidal strength. In periods of exceptionally high river discharge there is no intrusion of sea water. Conversely, during periods of low river flow when evaporation exceeds fresh water inflow, there is a large nett inflow of saline water. During flood tide the saline wedge moves along the bottom at a velocity ranging from an average of 50cm/sec in Reeves Channel to 10-15 cm/sec in Lake King...Therefore it is clear that the scour is caused by the movement of saline bottom water into the lake...

Salinity in the Lakes was the subject of a Parliamentary Public Works Committee inquiry in 1952; it concluded that there had not been an appreciable increase in salinity of the Lakes as a result of the artificial opening. Bird (1978) however provides evidence based primarily on Phragmites die back, to support a hypothesis of salinity increase since 1889, and the results of this investigation add substantially more weight to the conclusion of salinity increase. The scour channel that has developed in Reeves Channel now provides a significantly deeper passage for the exchange of water between the main body of the Lakes and Bass Strait. This has increased saltwater intrusion into the Lakes system by reducing the mean velocity of the lake water outflow but also a smaller proportion of the water column is affected by the outflow during ebb tide (Hinwood 1964)...Thus saline water is pumped into the Lakes and only exported after vertical mixing with lake water.

IT SEEMS INCONESTABLE THAT SALINITY INCREASE WITHIN THE LAKE SYSTEM HAS OCCURRED AS A DIRECT RESULT OF THE ARTIFICIAL OPENING OF THE LAKES. THE RESULTS OF THIS STUDY HIGHLIGHT THE FACT THAT A CONTINUED DEEPENING OF THE LAKE BOTTOM DUE TO SCOUR IS CAUSING A STEADY INCREASE IN THE SALINITY OF THE LAKES. IT IS CONTESTED THAT THIS IS OCCURRING DUE TO THE INABILITY OF THE EBB CURRENT TO FLUSH OUT THE SALINE BOTTOM WATER WHICH INTRUDES DURING FLOOD TIDE...

THE SALINITY OF THE LAKES IS BELIEVED TO BE STEADILY INCREASING BY INTRUSION OF SALINE WATER ALONG THE SCOUR CHANNELS DURING FLOOD TIDE, AND LITTLE OR NO FLUSHING OF THIS LOWER LAYER OF SALINE WATER DURING EBB TIDE..."

Is this the main reason why the Lakes are suffering from Saltwater Intrusion? For these large tugs to keep working with the Bass Strait Oil & Gas Industry?