Journal of the Royal Society of Western Australia, 86:119-122, 2003 
Is the salinity of Lake Clifton (Yalgorup National Park) increasing? 
B Knott 1 , L Bruce 2 , J Lane 3 , Y Konishi 1 & C Burke 14 
1 M092-Zoology, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009 
2 M015-Centre for Water Research, The University of Western Australia, 35 Stirling Highway, Crawley WA 6009 
Science Division, Department of Conservation and Land Management, 14 Queen Street, Busselton, WA 6280 
4 Present address: School of.Aquaculture, University of Tasmania at Launceston, Locked Bag 1-370, Launceston TAS 7250 
El bknott@cyllene.uwa.edu.au, bruce@cwr.uwa.edu.au, jiml@calm.wa.gov.au, C.Burke@utas.edu.au. 
(Manuscript received December 2000; accepted November 2003) 
Abstract 
Salinity of Lake Clifton, within Yalgorup National Park, Western Australia, varies annually in 
step with the annual change in water level. During the 1980s, salinity in the northernmost, 
permanent basin of the lake was hyposaline, varying between 8-32 g L 1 . By the late 1990s, however, 
recorded salinity values varied between 25-49 g L' 1 . This brief communication serves to initiate 
discussion on whether salinity in the lake really is increasing. If the salinity is increasing, then the 
scientific values of this lake are threatened. 
Keywords: Lake Clifton, salinity. Western Australia 
Introduction 
The limnologically-diverse lakes forming the Yalgorup 
National Park wetland (Fig 1) in south-western Western 
Australia constitute a natural laboratory of international 
scientific significance. The 10 km long reef of thrombolitic 
microbialites along the eastern shoreline of Lake Clifton 
(Moore et al. 1984) is a significant natural laboratory for 
investigating biogeochemical processes (Burne & Moore 
1987; Moore 1987, 1990; Moore & Turner 1988; Moore & 
Burne 1994; Konishi et al. 2001). The lake is listed (jointly 
with lakes McLarty and Mealup and the Peel-Harvey 
Estuary) under the "Ramsar" Convention on wetlands as 
a Wetland of International Importance Especially as 
Waterfowl Habitat (Anon 1990). 
Lake Clifton comprises essentially three basins; the 
northernmost is -4.5 m deep and together with the 
middle basin is permanent; the southernmost basin dries 
out in summer. With no surface outflow and only 
occasional minor surface input (Davies & Lane 1996), the 
-1 m annual fluctuation in water level of the lake is 
controlled by ground water and the balance between 
rainfall and evaporation. 
Lake salinity 
In March, 1972, Williams & Buckney (1976) recorded a 
salinity of 15.3 g L° in Lake Clifton. Moore (cited in 
Moore et al 1984) recorded a salinity range of 17-30 g L 1 
in 1979. In July 1983, after heavy rain, salinity of the lake 
near the aquifer outflow was 8.4 g L* 1 . During the 1980s, 
Lake Clifton was hyposaline and the following salinity 
ranges were recorded; 17-26 g L’ 1 adjacent to transect A, 
15-32 g L 1 adjacent to transect C, from two sites 
measured monthly in 1984 (Moore 1993). Values recorded 
monthly between May 1985, and July 1986, at the surface 
and near the bottom of the water column at three sites in 
© Royal Society of Western Australia 2003 
F12 (in Moore 1993) are equivalent to transects A and C, 
respectively. 
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