Limnological characteristics of two coastal Dune Lakes, Jervis Bay, South Eastern Australia

Abstract

Limnological features of two permanent, closed, coastal dune lakes that are separated by only about 400 m are reported. The depth of Lake Windermere fluctuated by about 7 m during this study (1982- 1988); however, fluctuations up to 15 m were observed between 1970 and 1988. Lake Windermere is exposed to wind mixing, is transparent and is usually mixed, or only weakly stratified. Lake McKenzie is semi-perched, darkly coloured and strongly stratified with an anoxic hypolimnion during summer. It is about one fifth of the surface area and half the depth of Lake Windermere and protected from wind mixing. Both lakes are acidic and have low salinity, and the dominant ions are sodium and chloride probably from precipitation of marine aerosols. Oxygen depletion in the hypolimnion of both lakes indicates a substantial organic load, the source of which is allochthonous material from the catchment rather than autochthonous material. Lake Windermere had higher densities of zooplankton (mostly Calamoecia tasmanica) than Lake McKenzie, but the latter lake had higher numbers of the predaceous Chaoborus sp. Lake McKenzie had higher invertebrate densities than Lake Windermere and these fluctuated widely between years, corresponding with variation in rainfall. Mayflies and chironomids were numerically dominant in Lake McKenzie, and caddisflies and chironomids were numerically dominant in Lake Windermere. Turtle and odonate predators were more common in Lake McKenzie than in Lake Windermere. It is postulated that biological interactions are more important in shaping the communities in Lake McKenzie and physical factors such as wave action are more important in Lake Windermere.

Temporal and spatial variation in landscape connectivity for a freshwater turtle in a temporally dynamic wetland system

“…Detailed descriptions of the study site are given by Kennett and Georges (1990), Norris et al (1993) and Georges (2007, 2008). Detailed descriptions of the study site are given by Kennett and Georges (1990), Norris et al (1993) and Georges (2007, 2008).…”

Clarification of Einfeldia Kieffer, 1922 (Diptera: Chironomidae) with E. australiensis (Freeman, 1961), comb. n. based on immature stages

“…Although 'X. australiensis' was not reported from there by Norris et al (1993), exuviae were found by Wright & Cranston (2000) to be common in late austral summer (April) but absent in cooler September.…”

Species richness and distribution of eastern Australian lake chironomids and chaoborids

“…The majority of lake faunal studies have reported that Chironomidae species richness in Australian lakes was very low (<12 species) (Fulton, 1983a,b; Timms, 1985; Norris et al. , 1993).…”

“…The most common method of sampling lake benthos has involved the collection of sediment samples, usually using grab samples from the profundal zones (Fulton, 1983a,b; Timms, 1985; Norris et al. , 1993) that may miss many chironomid habitats (Franquet & Pont, 1996).…”

“…For example, Tasmanian lakes were sampled by Timms (1978) and Fulton (1983a,b) while Arthington et al. (1986) sampled a number of Fraser Island lakes (Queensland) and single lakes have been sampled at Jervis Bay (south‐eastern Australia; Norris et al. , 1993; Wright & Cranston, 2000), and Lake Barrine (Queensland; Dimitriadis & Cranston, 2001).…”