Sediment phosphorus cycling in a large shallow lake: spatio-temporal variation in phosphorus pools and release
Spears, Bryan M.; Carvalho, Laurence; Perkins, Rupert; Kirika, Alex; Paterson, David M.. 2007 Sediment phosphorus cycling in a large shallow lake: spatio-temporal variation in phosphorus pools and release. Hydrobiologia, 584. 37-48. 10.1007/s10750-007-0610-0Full text not available from this repository.
Sediment and water column phosphorus fractions were recorded monthly for one year (April 2004–April 2005) in a shallow lake recovering from nutrient pollution (Loch Leven, Scotland). Equilibrium phosphate concentration (EPC0) and gross sediment phosphorus (P) release rates were estimated from laboratory experiments. Pore water and organic P pools were lowest during warm water periods whereas bottom water P was lowest during cold water periods. Reductant-soluble, organic, metal oxide-adsorbed, residual and sediment total phosphorus pools all varied significantly with overlying water depth. Short-term, high magnitude, redox initiated P release events occurred in late summer and winter as a result of anoxic sediment conditions. Lower magnitude long-term release conditions were maintained for most of the year, most likely as a result of organic P cycling and maintenance of high concentration gradients between the pore and bottom water P pools. Estimates of summer P uptake/release rates, across an intact sediment-water interface, suggested that maximum gross internal release was ~12 mg SRP m−2 lake surface area d−1 with EPC0 values ranging between 180 and 270 μg P L−1. This study highlights the biological mediation of internal loading in shallow eutrophic lakes, and in particular, the role of sediment algae in decreasing, and sediment bacteria in enhancing, sediment P release.
|Programmes:||CEH Programmes pre-2009 publications > Biogeochemistry
CEH Programmes pre-2009 publications > Water
|Additional Keywords:||sediment, phosphorus, mobility, bio-regulation, seasonality, loch leven|
|NORA Subject Terms:||Ecology and Environment
|Date made live:||25 Jan 2008 15:47|
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