Latest Findings


Commentary from Full Monitoring (FM) at Tomahawk Lagoon (TL) on July 25th 2018.


Air temperature ranged from 6.5 oC at 10.39 to 8.8 oC at 2.00. A cool day.

The wind was starting to build through out the day, 6.4km/h -9.7 km/h at 2.00.

Wind direction ENE

No rainfall during the day, 16 mm rain fell over the previous 4 days.


Site 1

10:40 am

65%ccv, light breeze, slight ripple, water very clear, cold day.

Abundant sea grass covered with silt, some pieces of Canadian pondweed.

Water boatman observed swimming in the weed along with many water fleas (Daphnia sp)

Abundant amphipods, one caddis fly larvae, abundant small snails and two Physa snails.

21 Black swans including 3 cygnets. Observed feeding very close to the hall.


Site 2

12:20 pm 

Sunny,cold wind from the east, ripples on clear water, very clear!!!

Abundant and healthy sea grass and pieces of Canadian pond weed.

Lots of Daphnia, abundant Amphipods and small snails, 2  Dytiscid beetles or water beetles.

Many birds all recorded on the e bird site.


Site 3

12:40 pm

Clear sky and cold wind, stream high and cloudy. No stock in the paddock.


Site 4

13:25 pm 

Continuous ripples, nor’easter wind, no clouds, very clear water, cold, relatively few birds.

A piece of Milfoil floated passed by, some weak patches of seagrass growing.

Our bucket sweep-12 shrimps, 3 amphipods, 2 small snails and 6 bloodworms (Chironmous midges).


Site 5

11:15 am

Moderate amount of water, very cold, breezy, a bit cloudy.

Weak patches of seagrass.

Bucket sweep-abundant Amphipods, few small snails.


DATA COMMENTS compared with 27th June.


Water levels have remained high due to rainfall on previous days


Site 4 and 5 show a slight decrease in salinity most likely due to extra freshwater falling and flowing through the catchment.


Water is very clear esp at S1 and 2 and cold.


DRP remains at quite a high concentration in the upper lagoon.


NNN remains high at most sites but very high in the stream flowing into the lagoon.


E. coli levels lower at all sites, S5 still exceeds guideline values.

Low water temperatures will slow down the bacteria growth and reproduction.


Algal levels have increased in the lower lagoon.


Bird numbers high in the upper lagoon, this is due to the significant growth of Seagrass in the upper lagoon.


Updated 5/08/2018