Effects of artificial embankments on river fish communities
Student name: Ms Roopam Shukla
Guide: Dr Prateek Sharma
Year of completion: 2013
Host Organisation: Vikramshila Biodiversity Research and Educational Center (VBREC)
Supervisor (Host Organisation): Prof Sunil Chaudhary and Mr Nachiket Kelkar
Abstract: Embankments provide many benefits to society but they have profound impacts on
river ecosystems. In addition to reducing habitat heterogeneity, alerting river
hydraulics, morphology they block fish migration between floodplains and main
river channel. The goal of this study was to evaluate how embankments affect fish
communities by comparing biomass and abundance at riprap embanked and
natural banks. The study was conducted at Vikramshila Gangetic Dolphin
Sanctuary. The effect of embankment on fish species, families have been discussed
in detail comparing the fishes at old and newly constructed embankments present
in the side and the main channel. We used detailed exploratory analyses (bar plots,
box plots, scatter plots) to compare biomass and abundance of all fish species
sampled, between embanked and natural bank sites. Nonmetric multidimensional
scaling was conducted to investigate associations between community composition
and embanked/natural sites. A total of 35 fish species belonging to 15 families were
sampled across all fishing replicates in both channels, and in the embanked and
non-embanked sites. Of these we recorded juveniles of 25 species. Natural sites had
overall higher fish abundance and biomass than embanked sites, as hypothesized.
On average, intact embankments recorded higher fish biomass as compared to
broken embankments in both main and side-channel reaches. With the risks
associated with increasing human interventions and future climate change such
bio- assessment becomes important to study the effect of hard engineered solutions
to mitigate flood hazard and protecting human settlements and other economically
important structure from bank erosion.
Key words: River, Embankment, Riprap, Climate change, Bioassessment,
