Record Details

DSpace at CIFT

View Archive Info
 

Metadata

 
Field Value
 
Title Impact of bottom trawling on epifauna off Veraval coast of India
 
Names Bhagirathan, U.
Meenakumari, B.
Madhu, V.R.
Panda, S.K.
Vaghela, D.T.
Jethva, J.K.
Date Issued 2014 (iso8601)
Abstract Experimental bottom trawling was conducted from MFV
Sagarkripa
at five transects of water depths 15-20 m,
21-25 m, 26-30 m, 31-35 m and 36-40 m in commercial trawling grounds to assess the impact of bottom trawling on the
epifauna off Veraval coast. Trawling was conducted for 17 months in a span of 20 months (September 2005-April 2007)
excluding the trawl ban period (June to August). Altogether 41 species of
gastropods
, 1 species of
scaphopod
, 19
species of
bivalves
, 3 species of
crab
, 3 species of
shrimps
, 2 species of
Balanus
, 1 species of
stomatopod
, 4 species of
finfishes
, 2 species of
brown algae
and 4 species of
octocorals
were identified. The soft corals found were
Litophyton
sp. and
Studeriotes
sp. (Christmas tree soft coral). The gorgonians collected were young stages of
Subergorgia suberosa
and
Juncella juncea
(Whip coral). The presence of octocorals recorded in the month of October, immediately after the
closed season (June to August) when the sea bottom is not heavily trawled suggests that this area is an abode of corals
and a favourable site for coral reef formation. But intense trawling in the succeeding months destroys these valuable
entities of ecosystem and the samples were not encountered in the subsequent months. The changes before and after
trawling in biodiversity indices were significant at 15-20 m. The abundance-biomass curve showed that the rate of stress
increased with water depth. The shallow depths are lightly trawled due to intermittent rocky nature of bottom and as
water depth increases, the trawling intensity increases. The analysis of similarity of percentages in Simper showed that
the dissimilarity of fauna before and after experimental trawling was more evident in lightly trawled area and remained
masked in heavily trawled area. Suggestions are made for the promotion of eco-friendly gears and for conducting
studies on appropriate un-trawled control sites for comparative assessment.
Management strategies have to be adopted
for the conservation and biodiversity protection of octocorals.
Genre Article
Topic Epifauna
Identifier Indian J. Geo Mar. Sci. 43: 297-312