Occurrence, abundance and seasonal distribution of benthic macro invertebrates in relation to the water quality and bottom soil properties in a fish pond

Abstract

enthic macroinvertebrates are essential components of aquatic biotic communities, performing several ecological roles in aquatic ecosystem functioning including nutrient circulation and recirculation. The species diversity, abundance and seasonal dynamics of benthic macroinvertebrates in a fish pond and their relation with pond bottom soil and water quality parameters were examined for a duration of one year during January to December. A total of 21 genera under four (4) different major groups of benthic invertebrates were identified. The mean abundance and a number of genera of each benthic macroinvertebrate group during the study period were in the following order: Oligochaeta (13 genera) > Chironomidae (4 genera) > Ceratopogonidae (2 genera) > Mollusca (2 genera). Among the genera, Tubifex spp., Pentaneura spp. and Culicoides spp. were most abundant and frequently occurred in each month. The interaction of the water quality parameters and soil properties played an important role in the structure of the benthic communities. The total nitrogen (%) content of the sediments was found to be positively correlated with the occurrence and abundance of Chironomidae (r = 0.764; p < 0.01). The relationship between environmental variables and assessed soil quality properties with the diversity indices showed significant variation over months, whereas the Simpson diversity index (Ds) was judged to be a lower level of contamination. The Shannon-Wiener index (H´) and Richness Index (R) and Pielou evenness (J) revealed that the benthic community distribution was uniform, and the water quality and soil parameters revealed tolerable conditions for the productivity of the pond. Considering the presence of 21 genera of macroinvertebrates, diversity index and properties of the soil and water, the fish pond can be considered as a moderately productive pond.