title: Impact of raking and bioturbation-mediated ecological manipulation on sediment-water phosphorus diagenesis: a mesocosm study supported with radioactive signature.
abstract: The study examined the impact of raking and fish bioturbation on modulating phosphorus (P) concentrations in the water and sediment under different trophic conditions. An outdoor experiment was set to monitor physicochemical and microbiological parameters of water and sediment influencing P diagenesis. A pilot study with radioactive32P was also performed under the agency of raking and bacteria (Bacillus sp.). Raking was more effective in release of P under unfertilized conditions by significantly enhancing orthophosphate (35%) and soluble reactive phosphate (31.8%) over respective controls. Bioturbation increased total and available P in sediments significantly as compared to control. The rates of increase were higher in the unfertilized conditions (17.6-28.4% for total P and 12.2 to 23.2% for available P) than the fertilized ones (6.5-12.4% for total P and 9.1 to 15% for available P). The combined effects of raking and bioturbation on orthophosphate and soluble reactive phosphate were also stronger under unfertilized state (54.5 and 81.8%) than fertilized ones (50 and 70%). The tracer signature showed that coupled action of introduced bacteria and repeated raking resulted in 59.2, 23 and 16% higher counts of radioactive P than the treatments receiving raking once, repeated raking and bacteria inoculation, respectively. Raking alone or in sync with bioturbation exerted pronounced impact on P diagenesis through induction of coupled mineralization and nutrient release. It has significant implication for performing regular raking of fish-farm sediments and manipulation of bottom-grazing fish to regulate mineralization of organic matter and release of obnoxious gases from the system. Further, they synergistically can enhance the buffering capacity against organic overload and help to maintain aquatic ecosystem health.
authors.affiliation: Department of Ecological Studies, University of Kalyani, Nadia, West Bengal, 741235, India. biswajoy2000@yahoo.com.|International Centre for Ecological Engineering, University of Kalyani, Kalyani, West Bengal, 741235, India. biswajoy2000@yahoo.com.
authors.forename: Jayanta K
authors.initials: JK
authors.lastname: Biswas
authors.affiliation: Department of Ecological Studies, University of Kalyani, Nadia, West Bengal, 741235, India.
authors.forename: Saumen
authors.initials: S
authors.lastname: Hazra
authors.affiliation: Department of Ecological Studies, University of Kalyani, Nadia, West Bengal, 741235, India.
authors.forename: Jayjit
authors.initials: J
authors.lastname: Majumdar
authors.affiliation: Department of Ecological Studies, University of Kalyani, Nadia, West Bengal, 741235, India.
authors.forename: Sushil K
authors.initials: SK
authors.lastname: Mandal
authors.affiliation: Faculty of Agriculture, Department of Soil and Water Sciences, University of Kafrelsheikh, Kafr El-Sheikh, 33 516, Egypt.|School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste Management, Laboratory of Soil- and Groundwater-Management, University of Wuppertal, Pauluskirchstraße 7, 42285, Wuppertal, Germany.
authors.forename: Sabry M
authors.initials: SM
authors.lastname: Shaheen
authors.affiliation: Department of Marine Science, University of Calcutta, 35, Ballygunge Circular Road, Kolkata, West Bengal, 700 019, India.
authors.forename: Santosh K
authors.initials: SK
authors.lastname: Sarkar
authors.affiliation: Department Soil Physics, Lysimeter Station Falkenberg Helmholtz Centre for Environmental Research - UFZ, Falkenberg 55, 39615, Altmaerkische Wische, Germany.
authors.forename: Ralph
authors.initials: R
authors.lastname: Meissner
authors.affiliation: Department of Applied Analytical and Physical Chemistry, Faculty of Bioscience Engineering, Ghent University, Coupure Links 653, 9000, Ghent, Belgium.
authors.forename: Erik
authors.initials: E
authors.lastname: Meers
authors.affiliation: School of Architecture and Civil Engineering, Institute of Foundation Engineering, Water- and Waste Management, Laboratory of Soil- and Groundwater-Management, University of Wuppertal, Pauluskirchstraße 7, 42285, Wuppertal, Germany.|Department of Environment and Energy, Sejong University, 98 Gunja-dong, Gwnagjin-gu, Seoul, 143-747, South Korea.
authors.forename: Jörg
authors.initials: J
authors.lastname: Rinklebe
mesh_terms: D017756:Aquaculture; D001407:Bacillus / Q000302:isolation & purification / Q000378:metabolism; D015169:Colony Count, Microbial; D017753:Ecosystem; D019015:Geologic Sediments / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis; D009573:Nitrites / Q000032:analysis; D010100:Oxygen / Q000032:analysis; D010710:Phosphates / Q000032:analysis; D010761:Phosphorus Radioisotopes / Q000032:analysis*; D010865:Pilot Projects; D014867:Water / Q000737:chemistry*; D014871:Water Microbiology; D014875:Water Pollutants, Radioactive / Q000032:analysis*
chemical_list: D009566:Nitrates; D009573:Nitrites; D010710:Phosphates; D010761:Phosphorus Radioisotopes; D014875:Water Pollutants, Radioactive; D014867:Water; D010100:Oxygen
keywords: Aquaculture; Bacteria; Bioturbation; Phosphorus exchange; Physical engineering