Spatio-temporal variability of surface sediment phosphorus fractions and water phosphorus concentration in Lake Peipsi (Estonia/Russia)

Abstract

Spatial and temporal variations in the contents of total phosphorus and five P-fractions were investigated in the surface sediments of large and shallow Lake Peipsi (area 3555 km2, mean depth 7.1 m) and compared with total phosphorus (TP), dissolved inorganic P (PO4-P) and dissolved oxygen (O2) concentration in the overlying water column. The aim of the study was to determine the relationships between the sediment P and water P concentration dynamics. Samples from the uppermost 10-cm layer of the sediment and water samples from surface and near-bottom layers were collected simultaneously at six monitoring stations twice a year (in March and August) from 2004 to 2009. The results indicated that the concentrations of different P-fractions in the studied sediments varied greatly. Total P in sediment ranged from 470 to 1400 mg kg–1 dry mass (DM), while the loosely bound (labile) P (NH4Cl-P) was the smallest and the most variable fraction (range from 3.6 to 43 mg kg–1 DM). The metal oxide-bound P (NaOH-P) was also highly variable (range from 48 to 660 mg kg–1 DM), whereas the concentration of calcium-bound P (HCl-P) was relatively even (range from 300 to 550 mg kg–1 DM) in all the studied sediments. Redundancy analysis results revealed that different phosphorus fractions in sediment had statistically significant relationships with bottom-water variables like TP (in winter) and O2 (in summer). Our results show that the oxygen conditions have deteriorated in the lake during the last decades, which may have enhanced the release of P from the sediments

Consequences of size-selective harvesting and changing climate on the pikeperch Sander lucioperca in two large shallow north temperate lakes

“…The lake is eutrophic with a mean total phosphorus concentration of 40 mg P m −3 and a total nitrogen concentration of 658 mg N m −3 in the ice-free period (Kangur and Möls, 2008). The existing limnological time-series data indicate that a deterioration of lake water quality has occurred (Kangur et al, 2009(Kangur et al, , 2013b.…”

Analysis of Internal Nutrient Load Dynamics from the Sediment in Lake Ziway

“…Moreover, Kangur, et al [18] and Zhang, et al [43] also reported that increased temperatures increase microbial processes and diffusion from the sediments resulting in elevated phosphorus concentration in the overlying water column. Furthermore, Søndergaard [42] explained that the increased temperature augments the rate of chemical diffusion and chemical processes, but the most significant impact on nutrient release is often via biological processes.…”

“…The results of the study for the spatial and temporal values of NO3-N, NO2-N, SRP, TP and TN concentrations and loads in the lake sediment samples in both composite and depth profiles are presented below: Sobczyński and Joniak [4] and Kangur, et al [18]. The main reason for the declining of SRP along depths of the sediment might be the 'bound up' of SRP with other metal complexes and not being actively released to the overlying water column.…”

Temporal and Vertical Relations between Various Environmental Factors in the Largest Lake of Łęczna-Włodawa Lake District (Eastern Poland)

“…A seasonal thermal stratification in deep lakes brings about vertical variation in phytoplankton composition [15,16]. In shallow water bodies, stratification is rarely observed [17], thus constant mixing of water column favour nutrient release from sediments [18]. Physico-chemical variables of lake water are the key components of water quality criteria for various uses, thus providing good indications of stressors in lake ecosystems [19].…”