title: Impact of Fish Farming on Phosphorus in Reservoir Sediments.
abstract: Fish farming has seriously influenced the aquatic environment in Sancha reservoir in SW China since 1985 and has been strongly restricted since 2005. Thus, phosphorus speciation in a sediment core dated between 1945 and 2010 at cm-resolution and in surface sediments from Sancha reservoir may allow us track how fish farming impacts phosphorus dynamics in lake sediments. Fish farming shifts the major binding forms of phosphorus in sediments from organic to residual phosphorus, which mostly originated from fish feed. Sorption to metal oxides and association with organic matters are important mechanisms for phosphorus immobilisation with low fish farming activities, whereas calcium-bound phosphorous had an essential contribution to sediment phosphorus increases under intensive fish framing. Notwithstanding the shifting, the aforementioned phosphorus fractions are usually inert in the lake environment, therefore changing phosphorus mobility little. The use of fish feed and water-purification reagents, the most important additives for fish farming, introduce not only phosphorus but also large amounts of sand-sized minerals such as quartz into the lake, to which phosphorus weakly sorbs. The sand-sized minerals as additional sorbents increase the pool of easily mobilisable phosphorus in sediments, which will slow down the recovery of reservoir water due to its rapid re-mobilisation.
authors.affiliation: Chengdu Academy of Environmental Sciences, Chengdu 610072, People's Republic China.
authors.forename: Binyang
authors.initials: B
authors.lastname: Jia
authors.affiliation: College of Architecture and Environment, Sichuan University, Chengdu 610065, People's Republic China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Environmental Geosciences, University of Basel, CH-4056 Basel, Switzerland.
authors.forename: Liyan
authors.initials: L
authors.lastname: Tian
authors.affiliation: Mineralogy and Petrography, University of Basel, CH-4056 Basel, Switzerland.
authors.forename: Leander
authors.initials: L
authors.lastname: Franz
authors.affiliation: Environmental Geosciences, University of Basel, CH-4056 Basel, Switzerland.
authors.forename: Christine
authors.initials: C
authors.lastname: Alewell
authors.affiliation: Environmental Geosciences, University of Basel, CH-4056 Basel, Switzerland.
authors.forename: Jen-How
authors.initials: JH
authors.lastname: Huang
mesh_terms: D000383:Agriculture; D000818:Animals; D002681:China; D005399:Fishes; D019015:Geologic Sediments / Q000737:chemistry*; D060106:Lakes; D010758:Phosphorus
chemical_list: D010758:Phosphorus