Aquaculture, Environmental Spillovers and Sustainable Development: Links and Policy Choices

Abstract

Although aquaculture as been practised for many centuries, it was in the past on quite a modest scale and limited to a few species e.g. carp. However, in recent decades, aquaculture has shown very rapid expansion. This is partly because catches of wild fish have expanded at a slower rate than demand and many new scientific and technological advances have been made in aquaculture. Furthermore, by the mid-1990s evidence available to scientists indicated that catches of wild fish had either reached, nearly reached or even exceeded their sustainable limits (Williams, 1997). Consequently, according to Meryl Williams (1997, p.18), Director of ICLARM, now “aquaculture is the major, though not sole hope, for improving the world’s fish production”. Aquaculture, particularly marine aquaculture, has become a new economic frontier. Just as humankind in the past experienced the Agricultural Revolution it seems now to be starting on an Aquaculture Revolution. Naturally, this raises the question of how sustainable it will be. The purpose of this article is to discuss the sustainability of aquaculture production. If expanded aquaculture production sets into motion forces that make it unsustainable, economic development based on it will be short lived. One should at least be aware how lack of economic sustainability of aquaculture production can arise, and be prepared to adopt policies to curb or prevent undesired trends in this. In this article, it is pointed out that (a) factors endogenous to the productive unit and (b) factors exogenous to individual productive units (such as environmental spillovers or externalities) and result in the unsustainable development of aquaculture. However, most attention in this article is given to adverse environmental spillovers as a contributor to lack of sustainability of aquaculture. This is because lack of sustainability in the endogenous case results from the rational choice of businesses 1 involved in aquaculture whereas the outcome when externalities exist can be inferior from the point of view of all or from a social viewpoint. There is consideration of the relative sustainability of extensive aquaculture systems versus intensive ones, and of the impact of aquaculture on the sustainability of natural fish stocks. Policies for regulating environmental spillovers to achieve a social economic gain, and thereby in most cases promote greater sustainability of aquaculture, are outlined and discussed. By concentrating on a particular sector, it is possible to identify various policy issues raised by the quest for sustainable development that may be overlooked in a macroeconomic context.