Diversity and distribution of Benthic fauna along the Valvanti river-a tributary of Mandovi estuary, Goa

Abstract

Benthic fauna diversity and distribution along the Valvanti river was studied for a period of one year. Since benthic fauna are regarded as the most reliable measures of pollution, it is important to study their diversity. The current investigation was conducted to study the structure, composition and diversity of benthic macroinvertebrate species. Four sampling stations along the Valvanti River were selected to collect samples. The current study reported 15 species of benthic macroinvertebrates, of which 13 were identified down to the genus level and two down to the family level. They were represented by six orders and nine families. Indicator species like Chironomus larvae and the Ceratopogonidae family dominated the sample. According to reports, the benthic fauna’s Shannon-wiener diversity index (H) was 2.33, indicating a moderate diversity implicating that the community has a reasonable number of species and there is no complete dominance of a single species. The Shannon Evenness Index was estimated to be 0.82, that indicated high evenness ie. the community’s species are fairly evenly distributed in terms of individual abundance. The Simpson’s Reciprocal Index was calculated to be 13.15 which meant that the community was highly diverse and for several species, the distribution of individuals was more uniform.