Trawl selectivity on Johnius dussumieri (Cuvier, 1830) along Gujarat, northwest coast of India
Trawl selectivity on Johnius dussumieri (Cuvier, 1830) along Gujarat, northwest coast of India
Date
2013
Authors
Madhu, V.R.
Panda, S.K.
Meenakumari, B.
Journal Title
Journal ISSN
Volume Title
Publisher
Society of Fisheries Technologists (India)
Abstract
The codend selectivity of Johnius dussumieri, an
important resource targeted by trawlers along
Gujarat coast was studied. Covered codend method
was used to derive the selection parameters of J.
dussumieri using a 40 mm diamond mesh codend.
Stacked haul method was used to derive the
selection parameters which were utilized for deriving
the selectivity estimates. The data on the
escapement through experimental codend collected
from 6 hauls were used for the analysis. The length
at 50% retention (L50)±SE of the species was derived
as 7.55 ±0.12 cm. The selection range was worked
out as 3.41 ±0.18 cm, selection factor as 0.19 and the
selection ratio as 0.45. Considering the length at
first maturity to be 122 mm, the optimum mesh size
required in the codend (diamond mesh) for conservation
of this species was found to be 64.2 mm.
Description
Keywords
trawl codend selectivity, diamond mesh, Johnius dussumieri, length at first maturity, optimum mesh size
Citation
Fishery Technology 2013: 50 (2), 121-125