Aquatic Life Health Quality Assessment of the Bolgoda Canal and Waga Stream with respect to Selected Physico-chemical Parameters and Bioindicators

Abstract

The relationship between some physico-chemical parameters and bioindicators in Bolgoda canal and Waga stream in Colombo, Sri Lanka was assessed from February to July 2010. The objective of the study was to evaluate the quality of aquatic health in the two water bodies using some physico-chemical parameters and bioindicators. Physico-chemical parameters of the Water bodies were measured. Macro invertebrates and phytoplankton were studied as biological indicators. Quantification of macro invertebrates were carried out and Pollution Tolerant Index (PTI) of Bolgoda canal and Waga stream was calculated according to the standard manual published by the United States Environmental Protection Agency (USEPA). Macro invertebrate component in the Bolgoda canal represented both moderately pollution tolerant (Nepa cinerea, Zygopteran nymphs) and pollution tolerant (Planorbella trivolvis, Promacea bridgesi, Gerris sp, Lethocerus americanus, Plea frontalis, Cerithiidae sp, Tubifex tubifex) organisms while in Waga stream only pollution sensitive organisms (Paludomous loricatus, Paludomous zeylanicus, Cylindrostesthus productus, Plecopteran nymphs, Psephenidae larvae, Aegla sp, Ephemeropteran nymphs) were reported. The PTI value of Bolgoda canal ranged from 17.00 to 19.90 where as in Waga stream was ranged from 34.00 to 39.60 indicating poor and good water quality respectively. The phytoplankton composition of both water bodies were analyzed using Shannon Wiener Diversity Index (SWDI). SWDI for phytoplankton in Bolgoda canal was ranged between 0.674±0.36 and 1.513±1.80 and in Waga stream was ranged from 1.89±0.72 -3.01±1.89 indicating low and high diversity respectively. Data analysis by Principle Component Analysis (PCA) showed that physico-chemical parameters, PTI and SWDI of the sampling locations in Bolgoda canal and Waga stream were clustered into three distinct groups according to the site selection. Regression analysis showed temperature, pH, DO, nitrate concentration and BOD had a significant effect on the PTI value of the Bolgoda canal and Waga stream.

Abundance-Biomass Comparison approach to assess the environmental stressors in Diyawannawa wetland in monsoonal and non-monsoonal seasons

“…Therefore, freshwater mollusk communities and populations are considered as important ecosystem health indicators (Ali and Fishar 2005;Idroos and Manage 2012).…”

“…The wide range of habitat preferences and presence of the slow-moving or sedentary adult stage of macrobenthic mollusks have made them ideal indicators for predicting the effects of disturbances on wetland communities (Oehlmann and Schulte-Oehlmann 2003). Many researchers have conducted studies to assess the suitability of using macrobenthic mollusk species to quantify the disturbances associated with aquatic ecosystems (Clarke 1990;Gamlath and Wijeyaratne 1997;Borja et al 2003;Borja and Muxika 2005;Dahanayaka and Wijeyaratne 2006;Dehghan-Madiseh et al 2012;Idroos and Manage 2012;Wijeyaratne and Bellanthudawa 2017). Most of such studies are based on the use of univariate assessment approaches such as the use of abundance data and use of diversity indices.…”

Evaluation of the water and sediment quality of a lotic water-body in the western coastal region of Sri Lanka using Rapid Bioassessment Protocol II (RBP II) of benthic macroinvertebrates

“…In a stream habitat at Dediyagala, Sri Lanka, significant correlations between dissolved oxygen concentration and Shannon-Wiener diversity index of benthic macroinvertebrates has been reported by Madushanka et al (2014). Significant effects of dissolved oxygen, nitrate concentration and biological oxygen demand on the pollution tolerance index of benthic macroinvertebrates in Bolgoda canal and Waga stream in Colombo have also been reported (Idroos and Manage 2012).…”

“…Sci. 22(2) (2017): 85-97 larvae had also been observed in highly organically polluted sites in the Bolgoda canal in Sri Lanka and are identified as ideal indications of unclean water where organic pollution is high and dissolved oxygen content is low (Idroos and Manage 2012).…”

“…However, diversity indices of benthic macro invertebrate communities have been used in several studies in order to monitor the environmental conditions (Gamlath and Wijeyaratne 1997;Dahanayaka and Wijeyaratne 2006;Perera et al 2012;Idroos and Manage 2012;Madhushanka et al 2014). In addition, many studies have concentrated on assessment of physicochemical parameters in the aquatic systems of Sri Lanka in order to identify the source and sink areas of pollutants (Sangakkara and Wijeyaratne 2015;Wijeyaratne 2016).…”