'Central Marine Fisheries Research Institute, Kochi'
Abstract
Marine fisheries in Tamil Nadu have undergone
tremendous change in terms of fishing pattern, fishing
method, extension of fishing grounds, composition
of fish catch and consequent increase in the total
fish catch in recent years. The recent demand from
industries involved in fish meal and fish oil encourages
targeted fishing for by-catch resulting in heavy landing
of low value by-catch in certain places along Tamil
Nadu coast. These by-catch are often dominated by
juveniles of many commercially important marine
finfishes and shell fishes. So it warrants some caution
and intervention. One of the methods to discourage
the indiscriminate exploitation of juveniles is to
impose a Minimum Legal Size (MLS) which is the size
at which a particular species can be legally retained
if caught. The advantage of a MLS is that it aids in
the control of two major problems in the fisheries
management, growth overfishing and recruitment
overfishing either by increasing the minimum size of
harvest or by increasing or maintaining the size of
the spawning stock. The most common method of
increasing the reproductive output through the use
of size limits is to set the minimum size at which the
females become sexually mature. As the individuals
of a species do not attain sexual maturity at the same
size, it can be a size at which higher proportions are
mature