Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern hemisphere perspective
Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern hemisphere perspective
Estuaries are dynamic transition zones acting as filters and transformers of nutrients passing from catchments to the sea. The authors propose an extension to an existing southern hemisphere model on nutrient dynamics in estuaries to include the relatively constricted, microtidal estuaries located along wave dominated coasts in the region, specifically focusing on the limiting macronutrients nitrogen (N) and phosphorus (P) and on key processes, including physical (e.g. flushing, mixing and sedimentation), geochemical (e.g. flocculation), biochemical (e.g. remineralisation) and biological (e.g. primary production) processes. A simplified model of the physical states (primarily controlled by hydrological characteristics) is used as the basis for the qualitative model, where these are defined in terms of characteristic salinity-induced stratification of the water column, flushing time and the mouth condition. Four physical states are identified: a freshwater-dominated state, freshwater pulsed/recovery state, marine-dominated state and the closed mouth state. The states and their physical characteristics largely resemble that of the earlier model, except that the extended model reflects the dynamics of restricted inlets and introduces the closed mouth state. This model specifically explores the variation within southern African estuarine systems to better inform research and management programmes on the appropriate trophic, temporal and spatial scales at which uncertainties in ecosystem functioning need resolving. It can also be applied to other regions in the southern hemisphere, and even the northern hemisphere, with similar hydrological and estuarine geomorphological characteristics (e.g. the Mediterranean coast, the west coasts of North and South America, and the south-west and south-eastern coasts of Australia).
Reference:
Taljaard, S, Van Niekerk, L and Joubert, WR. 2009. Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern hemisphere perspective. Estuarine, Coastal and Shelf Science, Vol.85(3), pp 407-421
Taljaard, S., Van Niekerk, L., & Joubert, W. (2009). Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern hemisphere perspective. http://hdl.handle.net/10204/3805
Taljaard, Susan, Lara Van Niekerk, and WR Joubert "Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern hemisphere perspective." (2009) http://hdl.handle.net/10204/3805
Taljaard S, Van Niekerk L, Joubert W. Extension of a qualitative model on nutrient cycling and transformation to include microtidal estuaries on wave-dominated coasts: Southern hemisphere perspective. 2009; http://hdl.handle.net/10204/3805.
Copyright: Elsevier 2009. This is the author's version of the work. It is posted here by permission of Elsevier for your personal use. Not for redistribution. The definitive version was published, the journal, Estuarine, Coastal and Shelf Science, Vol.85(3), pp 407-421