Role of diatoms as indicators of pollution gradients

Abstract

The impact of liquid wastes from a paper mill on the benthic diatoms in flowing waters has been studied for a period of two years. Water and algal samples were analysed at monthly intervals at three sites along the course of the river, along with raw effluents. The water before the confluence of effluents was well oxygenated with an alkaline pH. Organic matter, NH3 and nutrients were recorded at low concentrations. At the entry of effluents, the water showed considerable decline in dissolved oxygen content, increase in organic matter, hardness, Cl, HCO3 and total dissolved solids. Diatoms constituted 61% by numerical abundance and were reduced to 25% of total algae at the entry of effluents. Multiple regression analysis was employed to discover the relative importance of various physicochemical variables on the abundance and distribution of diatoms at various sampling stations. Mathematical equations were derived involving the physicochemical variables for better prediction of algal number.

Spatial distribution of benthic algae in the Gangqu River, Shangrila, China

“…TDS was another significant variable affecting the spatial pattern of benthic algae, which was negatively correlated with the third CCA axis (r = -0.509, P = 0.002). The study carried out by Sudhakar et al (1994) and Bate et al (2004) also found out TDS was an important factor for the distribution of diatom communities. In general, TDSs comprise inorganic salts (principally calcium, magnesium, potassium, sodium, bicarbonates, chlorides, and sulfates) and some small amounts of organic matter that are dissolved in water.…”

Hydrobiological Study of Algae of an Urban Freshwater River

“…These are very suitable organisms for the determination of the impact of toxic substances on the aquatic environment because any effect on the lower level of the food chain will also have consequence on the higher level (Joubert, 1980). Algae are used for assessing the degree of pollution or as indicator of water pollution of different water bodies (Trivedy, 1986;Sudhaker et al, 1994;Dwivedi and Pandey, 2002).…”

Effects of Kaduna Refining and Petrochemical Corporation Effluents on the Abundance and Distribution of Phytoplankton Community along River Rido, Kaduna, Nigeria

“…They are the base of the food chain in open water bodies and also provide food for organisms that are higher in the trophic levels [4,5]. Phytoplankton play a critical role in primary production, nutrient cycling and food web, and are used in assessing the degree of pollution or as indicators of Pollution of different water bodies due to their very sensitive nature and response to changes in their environment [6][7][8]. In a fresh water bodies changes in phytoplankton community can result in changes in the fish production and the entire productivity of water, because once the community of plankton change by the effects of pollutants; the structure, stability and function of ecological system can be changed as well.…”