Environment and aquaculture in developing countries

Aquaculture and Conservation of Genetic Diversity

STEFANO CATAUDELLA

Dipartimento di Biologia

Universita di Roma "Tor Vergata"

Via E. Carneuale, 00173 Rome, Italy

DONATELLA CROS~I

Central Institute for Marine Research TICRAM)

Respighi 5, 00197 Rome, Italy

CATAUDELLA, S. and D. CROSETTI. 1993. Aquaculture and conservation of genetic diversity,

p. 60-73. In R.S.V. Pullin, H. Rnsenthal and J.L. Maclean (eds.) Environment and aquaculture

in developing countries. ICLARM Conf. Proc. 31, 359 p.

Abstract

The history of aquaculture genetics and the effwta of aquaculture on natural aquatic genetic

resourcee are summarized. Modern approaches to fish genetic characterization are discussed. Fish

gene pools and genetic impoverishment in fish populations are reviewed with reference to envi-

ronmental change, the effects of capture fisheries and enhanced fisheries, introduction of exotic

species and hybridization. The mnservation of fish genetic resources ia considered extremely

important and approaches to ex situ conservation are discussed, together with examples of

international, regional and national efforta.

Introduction

Agriculture and animal husbandry
have been developed and intensified by
sustained manipulation and modification
of natural ecological balances. Wide knowl-
edge of living organisms and terrestrial
ecosystems has brought understanding of
the effects of thousands of years of such
manipulations and awareness that they
define the place of humans in nature.
During this process, however, genetic
resources and potential have been irre-
trievably lost. These losses have ethical
and esthetic aspects as well as causing an
actual diminution ofproduction potential.

Living aquatic resources, although

exploited by man since ancient times, have

so far suffered less than terrestrial re-

sources in this context. However, the

dXiculty of access to aquatic environments

and the size of the hydrosphere have not

prevented humans from overexploitingfish

stocks and degrading many aquatic envi-

ronments through the impact of activities

on land.

Conservation of genetic resources in

relation to aquaculture must take into

account the two main approaches to

aquaculture: zootechnical and ecological.

The former follows the principles of inten-

sive rearing, using breeds adapted to the