Frankland River

The Frankland River is the lower half of the greater Frankland-Gordon River catchment. The Gordon River becomes the Frankland River just north of the Frankland township and the Frankland-Gordon River is the longest River on the South Coast. The Frankland flows through incised valleys in the southern forests, draining into Nornalup Inlet, where the annual rainfall is 1400 mm.

Gordon River

The Gordon River, the major tributary of the Frankland River, has its head-waters in agricultural areas south-west of Broomehill. The Frankland-Gordon River is 400 kilometres long and is the longest River on the South Coast. The rainfall in the Gordon River catchment is less than 500 millimetres per annum. About 85% of the Frankland-Gordon River catchment, mostly about the 800 mm rainfall isohyet, is cleared for agriculture.

The five Frankland River and six Gordon River sites were sampled in November 2007.

Frankland River

The Western Minnow and Western Pygmy Perch were found at all sites. Night Fish were found at sites FRA01, FRA03 and FRA05.

One Balston's Pygmy Perch was found at site FRA03 and Freshwater Cobbler were found at sites FRA01 and FRA02. Shrimp were found at all sites apart from FRA05.

Gambusia, which is an introduced fish species, were found at site FRA03 and FRA05.

Marron, Long Necked Turtles, Freshwater Crayfish (Cherax crassimanus) and a Sea Mullet were all found in the Frankland River.

Pictures of these can be viewed in the gallery.

Gordon River

No species were recorded at site GOR01.

Hardy Heads were found at site GOR02, GOR05 and GOR06 and Shrimp were found at all sites apart from GOR02 and GOR06.

The introduced species Gambusia was recorded at all sites apart from GOR04.

Koonac and fresh water crayfish species Cherax preissii and Cherax crassimanus were also found in the Gordon River. Five Long Necked Turtles were also recorded.

Frankland River

Four of the five sites along the River were in pristine condition and very little evidence of disturbance was found. Site FRA07 was slightly disturbed and was determined to be in B grade condition.

Gordon River

All sites sampled were in a slightly degraded condition. The condition of each sites ranged from B2 to B3.

Frankland River

Water samples were taken once from each site so while they help describe the water quality at the time of sampling they can not be used to explain the overall condition of the river for the rest of the time.

The Frankland River is a brackish system with most sites sampled recording salinity level greater than 9.3mS/cm. Site FRA04, which is on Elise Brook, was fresh.

Sites FRA01 and FRA02 were of neutral pH and FRA04 was acidic. The remaining sites, in the lower catchment, were basic with pH levels above 8.0. These sites exceeded the ANZECC guidelines for pH.

The turbidity recorded at FRA01 was low, however it was moderate at FRA02, FRA03 and FRA05. Site FRA07 was very high.

All sites recorded low to moderate levels of total phosphorus and total nitrogen.

Gordon River

Water samples were taken once from each site so while they help describe the water quality at the time of sampling they can not be used to explain the overall condition of the river for the rest of the time.

The Gordon River is a brackish system with all site recording a salinity greater than 11.5mS/cm. Site GOR01 was saline with a salinity of 41.5mS/cm.

All six sites recorded basic levels of pH. Each of the sites, apart from GOR06 exceeded the ANZECC guideline of 8.0 pH.

The turbidity for all sites were low, apart from site GOR06 which recorded 6.6 NTU.

Only one site GOR06 recorded low levels of total phosphorous and total nitrogen. All other sites moderate levels.