Sediment phosphorus characteristics in the clearwater state of Lake Mogan, Turkey

Abstract

This study examined the vertical distributions of total phosphorus (TP) and phosphorus fractions, and the iron and organic matter, in the littoral sediment in a macrophyte-dominated, clearwater state in Lake Mogan between September 2005 and August 2006. Benthic macroinvertebrates and total bacteria in the sediment also were determined. No clear seasonal or depth-related (0-20 cm) patterns were found in sediment concentrations for the measured parameters. The phosphorus release was quantitatively very low, and a negative phosphorus release (-0.132 μg m -2 day -1 ) was measured during the summer months. The TP concentrations of the sediment samples ranged between 675.00 and 1463.80 μg g -1 dry weight (DW), and the trophic level of the lake was eutrophic. On average, inorganic phosphorus fractions comprised the largest fraction (63%), while organic-bound phosphorus (Org ≈ P) constituted 37% of the TP in Lake Mogan. The most important phosphorus-immobilizing factors are high iron content (14 200-47 750 μg g -1 DW), the sediment's clay content (47.80-51.80%), and an abundance of macrophytes at the sampling station. The low abundance of benthic macroinvertebrates (510-850 individuals m -2 ), which depend on sediments with high iron and low organic matter (5.42-13.30%), played a role in the sediment phosphorus retention. Although bacterial abundance in the surficial sediment appeared to be positively correlated to temperature, the overlying water did not experience anoxic conditions, supporting a state in which bacteria were able to retain phosphorus in their cell structures. Long-term changes in the sediments of Lake Mogan must be monitored lake. In order to optimize the management of the lake, and to determine the longevity of a clearwater state following management measures and continued external phosphorus loading, long-term changes in the sediments of Lake Morgan must be monitored.

Longitudinal heterogeneity of sediment characteristics during southwest monsoon season in hyper-eutrophic Krishnagiri reservoir, India

“…The reservoir sediment phosphorus fractions exhibited a majority of inorg-P fractions, consistent with the results reported by the authors Pulatsu et al (2008) and Søndergaard et al (1996). Org-P in this study was measured to be 24.1% of the TP fractions in the month of June 2008.…”

Paleolimnological record as an indication of incipient eutrophication in an oligotrophic subtropical coastal lake in Southern Brazil

“…The authors also found a significant correlation between sediment TC and TP concentrations in the vertical profiles, as observed in Peri Lake. Pulatsu et al (2008) found that bacteria in oxic sediments can retain P, what could also have happened in the top layers of Peri cores, resulting in the higher TP content observed, especially in core P1. According to Fontes et al (2013), bacterial community plays an important role in the metabolism of Peri Lake and, thus, influence nutrient dynamics and record in the sediments.…”

Phytoplankton functional groups provide a quality assessment method by the Q assemblage index in Lake Mogan (Turkey)

“…Besides recreational use, Lake Mogan has been identified as an important water bird area and has had protected status since 1990. A study of phosphorus release from the littoral sediment showed that the external phosphorus load must be reduced to control the eutrophication (Pulatsü et al, 2009).…”