Understanding the Ecological Response of Planktic and Benthic Epipelic Algae to Environmental Factors in an Urban Rivers System

Abstract

Many studies have been concentrated on the distribution of algae in lakes, rivers, and seas, however, few studies have been concerned about their distribution and relation with polluted urban rivers. In this study, the spatio-temporal variation characteristics of water quality and algae community in Nanjing city were investigated with microscopic examination for one year. Results showed that the water pollution in this area was mainly related to high concentration of nitrogen (NH3-N and TN (Total nitrogen). There was a total of 77 species of algae in the studied rivers from June 2016 to May 2017, among which 73 species of planktic algae and 34 species of epipelic algae, in which the abundance and biomass of the latter were 1925 and 904 times that of the former, respectively. The two kinds of algae had different change tendencies which were related to seasons. For planktic algae, the abundance and biomass decreased in this season sequence: summer, spring, autumn, and winter. For epipelic algae, the abundance and biomass were relatively higher in winter. The dominant community of planktic algae was Chlorophyta-Bacillariophyceae-Cyanobacteria type, while that of epipelic algae was Bacillariophyceae—Cyanobacteria type. Most of the present algae were bi-trophic species, and were tightly related to the pollution characteristics of the rivers. The key environmental factors for planktic algae are T, TN, and TP, and those for Epipelic algae are N:P and TN. The relation between the community composition of planktic and epipelic algae and environmental parameters are highly complex, and it is worth carrying out further study to clarify their interaction mechanism.

Benthic Algal Community in Relationship to Perturbation in the Tiko Mangrove Estuary Cameroon

“…Changes in vegetation cover have been shown to influence algal community [9]. The abundance of diatoms is an indication of high nutrient status of the sites.…”

“…Algae have responded to variations in water chemistry, season, and physiography variables [8]. Studies conducted in tropical and subtropical Africa indicated that the community assemblages of diatoms were impacted by human induced water quality alterations [5] [9] [10] [11] [12]. Being microscopic, they are the first to sense and respond to environmental changes.…”

Special Issue “The Response of the Plankton Community to Environmental Stress”

“…Xia et al [5] showed that although eutrophication is a key stressor for algae, planktonic and epipelic algae are affected differently by nutrients. Temperature, TP, and TN can be regarded as main stressors for planktonic algae, whereas TN and N:P ratios are more critical for epipelic algae.…”