Reviews in Fish Biology and Fisheries 13: 165–175, 2003.
© 2004 Kluwer Academic Publishers. Printed in the Netherlands.
Species studies in sea ranching: an overview and economic perspectives
S. Mustafa, S. Saad & R.A. Rahman
Borneo Marine Research Institute, Universiti Malaysia Sabah, 88999 Kota Kinabalu, Sabah, Malaysia
Introduction page 165
Deﬁning success 165
Economic effectiveness 166
Species studies 167
The idea of stock enhancement and sea ranching
sounds attracting to those interested in increasing
the landings from sea. Experience with several stock
enhancement projects, however, shows that assuming
a sure increase in catches of species because their
juveniles are seeded in the sea is over-simplistic.
Whether or not stock enhancement efforts achieve
increased ﬁshery production depends on a number
of factors and strategies. We need scientiﬁc analysis
to ﬁnd answers, and science is very investigative; it
goes beyond mere landings, and examines how are
they achieved, what processes are involved, what
is the quality of landings, what are the short-term
and long-term implications, and much more. A
large number of problems have to be addressed and
convincing answers found through practical demon-
stration before gaining strong scientiﬁc backing for an
activity such as sea ranching. Although there might
be economic compulsions, society’s expectations,
lobbies and government priorities, these should only
expedite scientiﬁc research, not impose a prescription
without critical analysis of the issues involved.
There can be no permanent measures of success for
sea ranching because science is dynamic and gener-
ates knowledge on a continuing basis, takes into
account new concerns and parameters, uses new tech-
niques of measurement, and adopts new approaches to
determining costs and beneﬁts.
Deﬁning and measuring the success of stock
enhancement programs in practical terms along with
a review of empirical data available for certain species
ranched experimentally or commercially are presented
in this article.
Deﬁning success in a large-scale sea ranching opera-
tion in a simple and straightforward way is difﬁcult.
Sea ranching may appear to be successful because of
favorable biological attributes of the animal selected
for release, its ecological interaction with environ-
mental components, supportive institutional frame-
work and policy, market trend and the way cost-beneﬁt
analyses are conducted. However, it might produce
impacts that are not so conspicuous.