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Diatom and dinoflagellate assemblages of the Hawkesbury River, N.S.W., over the last two centuries: evidence for changes in hydrology

Citation

McMinn, A and Heijnis, H and Murray, A and Hallegraeff, GM, Diatom and dinoflagellate assemblages of the Hawkesbury River, N.S.W., over the last two centuries: evidence for changes in hydrology, Alcheringa, 28, (2) pp. 505-514. ISSN 0311-5518 (2004) [Refereed Article]

DOI: doi:10.1080/03115510408619299

Abstract

Diatom and dinoflagellate cyst analysis of a 77 cm long sediment core from Cowan Creek, Hawkesbury River estuary, N.S.W., revealed changes in the catchment hydrology over the last 266 years. High abundances of the freshwater/brackish diatom genus Cyclotella at the base of the core imply sustained periods of reduced salinity that now no longer occur. Reduction of freshwater flow after approximately circa 1800 (60 cm) has allowed the development of marine planktonic diatoms Thalassiosira spp., Ditylum brightwellii, Rhizosolenia setigera, Pseudo-nitzschia pungens and Chaetoceros spp. Benthic diatom diversity has remained relatively unchanged. The toxic dinoflagellate Gymnodinium catenatum, although identified in a cyst survey in April 1995, was not found in the sediment cores. Changes in dinoflagellate assemblage are consistent with the effects of increasing urbanisation and eutrophication. © AAP.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geology
Research Field:Sedimentology
Objective Division:Environment
Objective Group:Other Environment
Objective Field:Environment not elsewhere classified
Author:McMinn, A (Professor Andrew McMinn)
Author:Murray, A (Mr Aaron Murray)
Author:Hallegraeff, GM (Professor Gustaaf Hallegraeff)
ID Code:32353
Year Published:2004
Web of Science® Times Cited:3
Deposited By:IASOS
Deposited On:2004-08-01
Last Modified:2005-06-06
Downloads:0

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