SS3.10 Ecological Implications of Terrestrial Inputs into Lakes and Ponds
Date: Tuesday, June 11, 2002
Time: 4:00:00 PM
Location: Esquimalt
 
HadwenWL, CCISR and CRC Tourism, Griffith University, Brisbane, Australia, w.hadwen@mailbox.gu.edu.au
Bunn, S, E, CCISR, Griffith University, Brisbane, Australia, s.bunn@mailbox.gu.edu.au
Arthington, A, H, CCISR and CRC Tourism, Griffith University, Brisbane, Australia, a.arthington@mailbox.gu.edu.au
Mosisch, T, D, Australian Water Quality Centre, South Australian Water Corporation, Adelaide, AUSTRALIA, thorsten.mosisch@sawater.com.au
 
PHYTOPLANKTON AND PERIPHYTON RESPONSES TO NUTRIENT ADDITIONS IN FIVE PERCHED DUNE LAKES ON FRASER ISLAND, AUSTRALIA.
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The ecological health of oligotrophic perched dune lakes on Fraser Island (Australia) is threatened by nutrient additions from tourists. To examine algal responses to nutrient enrichment, bioassays were implemented in five lakes during the 2000-2001 summer. Bioassays were incubated in situ with control (no nutrients added), nitrogen, phosphorus and nitrogen + phosphorus nutrient addition treatments. Responses of phytoplankton communities to treatments were temporally variable, with significant differences between treatments in early summer (November 2000) but not late summer (January 2001). Furthermore, treatments elicited different responses in each lake, with phytoplankton biomass increasing with phosphorus additions in one lake, nitrogen additions in another lake and nitrogen + phosphorus additions in the remaining lakes. In the periphyton bioassays, biomass responses mimicked those in the phytoplankton bioassays, although no significant differences between treatments were detected. In these oligotrophic dune lakes, nutrient additions from tourist sources are likely to influence algal biomass, although the degree to which changes occur will depend on the timing of nutrient additions (early versus late summer) and the type (N, P or N + P) of nutrients added.