ASSESSMENT OF ICHTHYOFAUNAL BIODIVERSITY OF SWARNA RIVER ESTUARY OF UDUPI DISTRICT IN KARNATAKA.
Loading...
Date
2021
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
KARNATAKA VETERINARY, ANIMAL AND FISHERIES SCIENCES UNIVERSITY, BIDAR
Abstract
The coastal ecosystems of Karnataka are situated closer to the Western Ghats,
which are considered as one of the global biodiversity hotspots. In view of this, the present
study was conducted on the ichthyofaunal diversity of estuarine system of Kodi-Bengre
region, which gives important insights on the abundance and seasonality of fish
diversity.From August 2019 - March 2020, a total of 65 species encountered belonging to
50 genera, 37 families and 11 orders were studied. Among them, Nematalosanasus was
found to be the most dominant species. Out of 10 orders, the order Perciformes stands first,
comprised of 22 families represented by 36 species and the order Clupiformes ranked
second with 2 families represented by 6 species. The seasonal abundance of ichthyofaunal
diversity recorded during post-monsoon (Oct-Jan) is more compared to pre-monsoon (Feb-
March) and monsoon (Aug-Sep). The diversity indices including Margalef's richness index
(d). Shannon-wiener index (H') (at log 10), Simpson index (A) and Pielou's evenness (J)
were calculated. The K- dominance curve plot showed that the diversity of species was
high near the bar mouth region and at the estuarine region. These showed the closely
similar diversity and proved that the number of species (richness) is more near the bar
mouth region. Bray-Curtis similarity index revealed that the maximum similarity was
found between pre-monsoon and monsoon seasons at S2 and S1 station. And the same
pattern was also evident in the MSD plot and the stress valve, which was overlain on the
MSD plot (0.13, 0.1 and 0.09), showed a good ordination of the samples
collected.Biodiversity of threatened ichthyofaunal species out of the recorded 65 species,
25 species were Not Evaluated, 35 species were Least Concern, 3 species were Data
Deficient, 1 species was Vulnerable, and 1 species Critically Endangered was recorded
from the Swarna River estuary.