Gillnet Selectivity and Fishing Pressure on Sardinella gibbosa (Bleeker, 1849) off Southeast Coast of India
Gillnet Selectivity and Fishing Pressure on Sardinella gibbosa (Bleeker, 1849) off Southeast Coast of India
Date
2015
Authors
Ravikumar, T
Neethiselvan, N
Velmurugan, R
Manojkumar
Sundaramoorthy, B
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Fisheries Technologists (India)Cochin
Abstract
A study was undertaken on the selectivity of small
meshed gillnets and fishing pressure on Sardinella
gibbosa along Thoothukudi, south east coast of India,
with the view to understand the impact of various
mesh sizes of gillnets on the fishery of S. gibbosa.
The selectivity of gill nets was analysed as described
by Sparre &Venema (1992) and the fishing pressure
on various length groups was analysed using FiSAT.
The study revealed a well-defined selectivity by
gillnets with 26, 28 and 30 mm mesh sizes. The
fishery was found un-affected by growth overfishing
on recruitment overfishing as the commercially
significant size group was found to be 110 to 160
mm which was higher than the estimated length at
first maturity (100 mm). However, during the
months from August to November notable landings
of juveniles were reported, which was mainly due
to the use of gillnets with 26 mm mesh size. The
selectivity parameters such as length at first capture
(lb), mean selection length (lc) and the escapement
length (ld) for the selected gillnets were found to
range from 90 to 107 mm, 115 to 135 mm and 145
to 165 mm respectively. The gillnet selection factor
for S. gibbosa was estimated as 4.50. The study
revealed the possibility for further increase in
fishing effort for S. gibbosa along this coast based on
the exploitation ratio (F/Z) of 0.39. The gillnet with
30 mm mesh size was found to be ideal for the
commercial exploitation of S. gibbosa along this
coast.
Description
Keywords
Gillnet selectivity, fishing pressure, Sardinella gibbosa, over fishing, optimum mesh size
Citation
Fishery Tech 53(2):80-87