Applicability and efficacy of diatom indices in water quality evaluation of the Chambal River in Central India

Abstract

Diatom indices have gained considerable popularity in estimation of the trophic state and degree of pollution in lotic ecosystems. However, their applicability and efficacy have rarely been tested in Indian streams and rivers. In the present study, benthic diatom assemblages were sampled at 27 sites along the Chambal River in Central India. PCA revealed three groups of sites, namely, heavily polluted (HVPL), moderately polluted (MDPL), and least polluted (SANT). A total of 100 diatom taxa belonging to 40 genera were identified. Brachysira vitrea (Grunow) was the most abundant species recorded from the least polluted sites with an average relative abundance of 29.52. Nitzschia amphibia (Grunow) was representative of heavily polluted sites (average relative abundance 31.71) whereas moderately polluted sites displayed a dominance of Achnanthidium minutissimum (Kϋtzing) with an average relative abundance of 26.33. CCA was used to explore the relationship between diatom assemblage composition and environmental variables. Seventeen different diatom indices were calculated using diatom assemblage data. The relationship between measured water quality variables and index scores was also investigated. Most of the diatom indices exhibited strong correlations with water quality variables including BOD, COD, conductivity, and nutrients, particularly phosphate. Best results were obtained for TDI and IPS indices which showed a high level of resolution with respect to discrimination of sites on the basis of pollution gradients. Water quality maps for the Chambal River were hence prepared in accordance with these two indices. However, satisfactory results with respect to water quality evaluation were also obtained by the application of EPI-D and IGD indices. The present study suggests that TDI and IPS are applicable for biomonitoring of rivers of Central India. Diatom indices, which are simpler to use such as IGD, may be considered, at least for a coarser evaluation of water quality.

Applicability of Benthic Diatom Indices Combined with Water Quality Valuation for Dish Lake from Nanjishan Nature Reserve, Lake Poyang

“…Indices of 18 European diatom were calculated, which were presented by numbers ranging from 1 to 20, indicating different grades for ecological health status. As confirmed in public references, the status of the water ecosystem could be divided into five grades, namely healthy (18)(19)(20), good (15)(16)(17), fair (12)(13)(14), poor (9-11) and very poor (1)(2)(3)(4)(5)(6)(7)(8). As illustrated in Figure 3, which was calculated using different water quality grades, SHE, IDP, EPI-D and SLA, %PT and ROTT troph were concentrated in a certain range without enough resolution.…”

“…These lakes were used for harvesting fish from the main lakes during the flooding season of Lake Poyang, by which feeding would bring a large number of nutrients to the dish lake ecosystem and puts these aquatic ecosystems at great risk [44,45]. As presented in Table 1, Zhan'bei, San'ni and Bai'sha lakes recorded the highest level for TN, TP, NH 4 + , COD and Chl, which has been given high attention in recent years [4,15]. Frequent human activities in this area and its proximity to the entrance of Ganjiang River into Lake Poyang also lead to the input and deposition of nutrients [37].…”

“…Lots of studies revealed that diatom communities could effectively respond in different ways for different types of contamination, such as nutrients, organic pollutants and heavy metal pollutants, which eventually made them effective environmental indicators of water quality [12,13]. Among them, benthic diatoms were widely accepted as representative species because they are widely available and easily accessible [14,15]. Furthermore, benthic diatoms are usually fixed to survive in a specific environment, tolerant to environmental changes and do not migrate due to environmental changes [16].…”

Freshwater diatom biomonitoring through benthic kick-net metabarcoding

“…At the species level, highly sensitive/sensitive taxa were detected mostly with all collection methods, however for some rarer species such as Epithemia gibba, rock scraping method failed to detect this species despite presence in all other collection methods. Rock scrapings are commonly used as the sole collection method for diatoms [14,15,78,79], which suggests that the kick-net approach facilitates the detection of ecological indicator taxa which otherwise may be missed from conventional sampling.…”

Evaluation of the ecological state of the major streams located in Doon valley using diatoms as indicators

“…The diatom indices have been widely used in various region of the world for monitoring water quality; Watanabe et al (1986) in Japan, Lobo et al (1995Lobo et al ( , 2004 in Brazil, Solak and Acs (2011) in Turkey. In India studies on the use of diatoms for monitoring are scarce; rivers and lakes of south India (Venkatachalapathy and Karthikeyan 2012, Venkatachalapathy et al 2014, Murulidhar and Murthy 2014, Mahadev et al 2016, Central India (Srivastava et al 2017) mountain streams and rivers in lesser Himalaya (Nautiyal et al 2007, Nautiyal and Mishra 2013.…”