Today, I went to Leanyer to have a look for fry of P. cyanodorsalis and
found plenty in the creeks that drain Leanyer swamp (Leanyer swamp is
marine). The creeks that were running were fresh water pH 7.2, TDS 30
parts per million, temp 26 deg C. The creeks that were not running were
brackish pH 7.8, TDS 18 parts per thousand, temp 34 deg C. there were some
brackish places that were warmer and did not have any fry. That is not
hard to explain because we have had spring tides since the heavy rains of
cyclone thelma, perhaps the 7 meter spring tides pushed the fresh water
back in places where there was no fresh water running creek to flush it
away. The creeks of leanyer drain into Buffalo Creek then the sea which
is about five kilometers away. The entire mud flats were very wet and
difficult to walk on. Ususally we are able to drive across the flats in a
4WD vehicle with caution. I also went to the mouth of Buffalo Creek about
200 meters from the Sea. There were plenty of adults and fry there, and
the water was normal sea water, pH 8.2, Salinity 34 ppt, temp 27 deg C.
All of these places mentioned are within 10 - 15 kilometers of the business
centre of Darwin NT.
Dave Wilson