66 Fish as feed inputs for aquaculture – Practices, sustainability and implications
- INTRODUCTION
Aquaculture, an age-old tradition that commenced at least two millennia ago in Asia,
has gradually transformed from an art form to a science over the last five to six decades.
Aquaculture currently provides over 50 percent of all fish and seafood consumed
globally (FAO, 2007). Asia has been in the forefront of most forms of aquaculture
development and continues to lead the global production, with a contribution of
54.37 million tonnes in 2004 valued at nearly US$57 billon. In 2004, Asian aquaculture
accounted for 91.5 and 80.8 percent of the global production and value, respectively.
As for any other primary production sector, aquaculture, globally or in Asia, cannot
be expected to continue to grow almost exponentially. Indeed, a slowing of the growth
rate has already been reported (FAO, 2007; De Silva and Hasan, 2007). The question,
therefore, is whether Asian aquaculture can, at best, sustain the current growth rate,
which over the last five years has averaged 6.8 percent per annum, or at worst, sustain
the current level of production. Aquaculture will also need to limit any long-term
impacts that it has on biodiversity and adjust to increasing demands on limited natural
resources such as water, land and feed ingredients. Simultaneously, aquaculture needs
to cater to increasing consumer demands for food safety, improved quality control
standards, traceability and associated certification and ethical attributes (Singer and
Mason, 2006), particularly in respect of exported aquaculture commodities. As Kutty
(1997) pointed out, aquaculture’s sustainability is no longer dependent only on
economic viability but also on maintenance of environmental integrity.
Feeds and feeding and associated raw material procurement and usage are central
to the success and sustainability of any animal farming system, and in this regard the
aquaculture sector is no exception. However, aquaculture, a relatively new and emerging
food production sector in many regions, is more often than not viewed in light of
increasing concerns for and perceptions of environmental integrity, sustainability and
prudent use of physical and biological resources. It has been reported that aquaculture
development is unprogressive or at least wasteful in its dependence on fishmeal and
fish oil (Box 1), two limited biological resources (Naylor et al., 1998, 2000), and its
use of exotics or alien species (Naylor, Williams and Strong, 2001). However, these
propositions have been strongly refuted by Hardy (2001) and Roth et al. (2002) and
by De Silva et al. (2006), respectively. There is general agreement that the growth and
sustainability of aquaculture will be significantly impacted by feed availability, efficacy
of feed utilization, feeding practices and potential advances in feed manufacture,
among others factors. These aspects are not secondary to those related to potential
genetic improvements, development of culture technologies and improvements in
disease prevention and control and hatchery techniques, all of which are essential for
sustaining future aquaculture development.
This study reviews the status of use of trash fish/low-value fish, as well as other
aquatic potential feed sources in aquaculture in the Asia-Pacific region and its possible
impacts. In this context, an attempt is made to assess the availability of all types of
feeds used in aquaculture in the Asia-Pacific region and evaluate the potential needs
and constraints associated with feed types, availability and efficacy of utilization. This
study is based on literature surveys, dedicated field studies in selected Asian nations
and on two case studies dedicated to feeds and feeding in China and Viet Nam. In view
of the diversity of the aquaculture practices in the Asia-Pacific region, and based on
Food and Agriculture Organization of the United Nations (FAO) production data
(FAO, 2007), an initial analysis was undertaken of the sector’s production trends as
they relate to culture environment, species/commodities cultured and the feed needs
and usage.