CORMORANTS AND THE GIPPSLAND LAKES FISHERY 
113 
the numbers not only of fishes but of Cormorants and other 
forms of life. Man alone is the culprit, but with him also lies 
the counter if action is taken in time. This is a much wider 
field, and lacking necessary facilities, was beyond what could 
be accomplished in detail, but at least some aspects could not 
be ignored. 
The graphs of quantities show that there has been a marked 
decrease particularly in three species of fishes which, unlike 
the other marketed fishes, appear to be entirely dependent 
upon the estuary throughout life. In the natural state the 
waters of the lakes were chiefly fresh to brackish, with increas- 
ing salinity only towards the entrance. These conditions were 
maintained by a natural sand bar between the lakes and the 
sea which was cast aside when flood waters entered the lakes 
from the rivers, and mechanically piled up again when the 
flow was normal, thus at all times keeping the condition of the 
waters constant. There were similar bars across the mouths 
of all streams entering the lakes. 
Aquatic plants, chiefly grasses, were plentiful, and it is 
known that the Ludrick feeds on some of these plants, and that 
they furnish a necessary enviromiient for much of the animal 
life upon which Bream and River Garfish feed. It is probable 
too that the aquatic grasses are an essential part of the 
spawning grounds of all three species. Although so important 
a link in the chain of vital factors, it was impossible to make 
a survey of the aquatic vegetation, but as an indication of 
what appears to be happening, the effect on one of the largest 
and most common of the plants, the Streaked Arrow Grass 
(Triglochin striata Ruiz.), may be cited as an example. This 
is a swamp grass which lives in fresh to brackish water, but 
apparently cannot exist for long in salt water. If, then, an 
artificial entrance permits the sea to flow freely into the lakes, 
it may be expected that this and other similar plants will be 
seriously affected if not destroyed, and if such plants are of 
considerable importance to the well-being of fishes dependent 
upon conditions within the lakes, the fishes in turn will be 
similarly affected if not destroyed. At present the waters of 
the lakes and for a considerable distance in the rivers are 
described as being “as salt as the sea.” The general effect on 
the Streaked Arrow Grass has been to destroy practically all 
growth above bottom level, only the root system remaining. 
Apparently if flooding is not too long delayed, the root system 
will survive and fresh growth will be given off. Should the 
floods be of short duration any new growth will soon again be 
