Diatoms, Spatial Distribution and Physicochemical Characteristics of the Wular Lake Sediments, Kashmir Valley, Jammu and Kashmir

Abstract

Lakes and wetlands are dynamic geomorphic units of a landscape that hold geochemical signatures of sediment provenance and paleo-environmental shifts and are major sinks for organic matter accumulation. The source of organic matter is diverse in lake sediments and varies widely with the type and size of the lake and hence it is important to understand the source of organic carbon (terrestrial or in situ) in lake systems in order to monitor the health of the lake. Wular lake, located in north Kashmir, is one of the largest fresh water lake in India, situated at an average elevation of 1580m ASL. The lake is fed by a number of watersheds that bring a diverse type of sediments and organic matter and thus deposit them into the Wular lake basin. In order to understand sediment distribution pattern, content and source of organic matter, sediment provenance and the persisting environment in the Wular lake, 32 lake floor sediment samples covering the entire lake were collected and analyzed for organic element analysis, CaCO3, organic matter, sediment texture and diatom analysis. The results indicated that sediments in the lake are dominated by silt and silty clay. The organic carbon in the lake ranged from 0.83%-4.52% and nitrogen varied from 0.06%-0.5%. The Carbon to Nitrogen (C/N) ratios (9.04 to 22.03) indicate a mixed source of organic carbon but dominated by in situ lake sources from the vascular and lake biota accumulation. The diatom analysis revealed the occurrence of a diverse type of species along the sampling sites present within the lake. The wide distribution of the diatom species such as Cymbella, Cyclotella and Tabularia etc. in the lake indicate high organic pollution and alkaline fresh water environment prevailing in the lake.

Bottom Sediment Characteristics of a Tropical Lake: Lake Tana, Ethiopia

“…The organic matter content in this study with an average of 16 g kg −1 (Figure 3b, Table A1) was greater than that of the limited data collected 20 years ago [62] but less than the study conducted 5 years ago that sampled the lake near the shoreline [35] that was dominated by aquatic plants [36]. The organic matter content on Lake Tana was small compared with Lake Abaya and Chamo [12] in Ethiopia, Lake Victoria [14] in Central Africa, and the Waler and Berijam lakes in India [19,63]. The low organic matter and total N content in Lake Tana is a consequence of agricultural land in the watershed that is low in organic matter and the shallow depth.…”

Holocene palaeoenvironmental records from the high-altitude Wular Lake, Western Himalayas

“…(a) Digital elevation model (DEM) of the Kashmir Valley with superimposed drainage pattern modified after Shah et al (2017) and (b) geology map of the study area modified after Thakur and Rawat (1992).…”

Paleoenvironmental shifts spanning the last ~6000 years and recent anthropogenic controls inferred from a high-altitude temperate lake: Anchar Lake, NW Himalaya

“…These are archived in loess/paleosol sediments, freshwater lake and paleolake sediments, cave deposits, and tree ring cores (for last few hundred years) among others. For example, investigations on the late Quaternary and Holocene paleoclimate shifts from NW Himalaya and Kashmir basin are commonly based on a number of multiproxy parameters including palynology (Kar and Quamar, 2018;Srivastava et al, 2017), environmental mineral magnetic studies (Basavaiah et al, 2010), dendrochronology (Borgaonkar et al, 1996;Ram and Borgaonkar, 2014), stable isotope analyses (Krishnamurthy et al, 1982(Krishnamurthy et al, , 1986Kusumgar, 1992;Kusumgar et al, 1980Kusumgar et al, , 1986, and geochemistry of sediments (Ahmad and Chandra, 2013;Babeesh et al, 2017;Chandra et al, 2016;Mishra et al, 2015), geomorphic surface processes (Babeesh et al, 2017b;Lone et al, 2017Lone et al, , 2018aLone et al, , 2018bLone et al, , 2018cShah et al, 2017), and geochronology (Meenakshi et al, 2018). As such, investigation of pedogenic paleosols and pollen profiles from Kashmir Valley have reflected warmer humid conditions and alternations of cool temperatewarm temperate-cool temperate cycles, respectively, during the past 17,000 yr BP (Agrawal et al, 1989).…”