Assessing the seasonal influence of sewage and agricultural nutrient inputs in a subtropical river estuary

Costanzo, SD, ODonohue, MJ and Dennison, WC (2003) Assessing the seasonal influence of sewage and agricultural nutrient inputs in a subtropical river estuary. Estuaries, 26 4A: 857-865. doi:10.1007/BF02803344

Author Costanzo, SD
ODonohue, MJ
Dennison, WC
Title Assessing the seasonal influence of sewage and agricultural nutrient inputs in a subtropical river estuary
Journal name Estuaries   Check publisher's open access policy
ISSN 0160-8347
Publication date 2003-01-01
Sub-type Article (original research)
DOI 10.1007/BF02803344
Volume 26
Issue 4A
Start page 857
End page 865
Total pages 9
Place of publication Lawrence, USA
Publisher Estuarine Research Federation
Language eng
Subject C1
300804 Environmental Impact Assessment
770406 Integrated (ecosystem) assessment and management
Abstract A combination of physical and chemical measurements and biological indicators identified nutrient impacts throughout an Australian subtropical river estuary. This was a balance of sewage inputs in the lower river and agricultural inputs in the mid-upper river, the combined influence being greater in the wet season due to greater agricultural surface runoff. Field sampling in the region was conducted at 6 sites within the river, over 5 surveys to encapsulate both wet and dry seasonal effects. Parameters assessed were tissue nitrogen (N) contents and delta(15)N signatures of mangroves and macroalgae, phytoplankton nutrient addition bioassays, and standard physical and chemical variables. Strong spatial (within river) and temporal (seasonal) variability was observed in all parameters. Poorest water quality was detected in the middle (agricultural) region of the river in the wet season, attributable to large diffuse inputs in this region. Water quality towards the river mouth remained constant irrespective of season due to strong oceanic flushing. Mangrove and macroalgal tissue delta(15)N and %N proved a successful combination for discerning sewage and agricultural inputs. Elevated delta(15)N and %N represented sewage inputs, whereas low delta(15)N and elevated %N was indicative of agricultural inputs. Phytoplankton bioassays found the system to be primarily responsive to nutrient additions in the warmer wet season, with negligible responses observed in the cooler dry season. These results indicate that the Tweed River is sensitive to the different anthropogenic activities in its catchment and that each activity has a unique influence on receiving water quality.
Keyword Environmental Sciences
Marine & Freshwater Biology
Phytoplankton Growth
North Queensland
Q-Index Code C1

Document type: Journal Article
Sub-type: Article (original research)
Collections: 2004 Higher Education Research Data Collection
School of Agriculture and Food Sciences
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Citation counts: TR Web of Science Citation Count  Cited 35 times in Thomson Reuters Web of Science Article | Citations
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Created: Wed, 15 Aug 2007, 12:10:28 EST