Aquaculture is frequently criticised for having a negative impact on the environment, which tends to overshadow its contributions to fighting hunger and alleviating poverty. However, it is unjustified to reject aquaculture – instead we should intensify our efforts to increase its sustainability. Aquaculture is crucial in our pursuit of global food security and good human health, as it offers a source of food that is rich in protein, essential fatty acids and vitamins and minerals. Furthermore, it offers a way to boost development by providing jobs, improving people’s incomes and increasing returns on natural resource use. We must ensure that the sector continues to expand, along sustainable principles, to provide more people with food and income, especially in areas like sub-Saharan Africa, Latin America and Asia where hunger and poverty prevail.

Basic knowledge of the immune systems of aquatic vertebrates and invertebrates is urgently needed to develop appropriate measures for disease prevention and/or control. Now that model systems for use with aquatic organisms have become available, experts from similar research sectors working with terrestrial animals might realise the new research opportunities in the aquaculture domain.

Today we still underestimate the critical role of microflora in the production biology of aquatic systems, e.g. in nutrient recycling, micronutrient generation, digestion and immune stimulation, etc. Proper R and D should generate recommendations for increased microbial management, resulting in more efficient use of resources and more sustainable production.

Domestication efforts should receive higher attention in order to achieve independence from natural stocks and open ways for the development of more efficient stocks through selective breeding.

A concerted multidisciplinary effort of oceanographers/marine biologists, fisheries scientists and aquaculture practitioners should better explore possible integration of aquaculture practices with fisheries management and eventually improve socio-economics of the fisheries sector in various regions of the world.

In view of future competition for freshwater resources, opportunities for integration of aquaculture with other food and/or bio-fuel production systems, aquatic as well as terrestrial, needs to be better explored and their sustainability impacts better documented. Off-shore industries that combine energy generation, food and feed production and blue biotech innovations offer great potential for large-scale applications. In this regard, we need to better understand energy and nutrient flows in existing/traditional systems (e.g. the large-scale polyculture systems in coastal China) to document the bioremediation effect of seaweed and mollusc production in highly eutrophic areas and/or in combination with monoculture "business aquaculture" practices.

More attention is also needed for the selection of species low in the food chain, especially those that can be farmed in extractive culture systems. Furthermore, species need to be better differentiated into products for bulk markets versus niche markets.

The use of modern biotechnology "omics" tools should make it possible to let aquaculture evolve from an empirical science to a knowledge-based biotechnology with much more emphasis on fundamental research in order to unravel the underlying mechanisms in growth and product quality of aquatic species, their endocrinology, immune systems, behaviour, etc. Application of proven experience from other disciplines in agriculture and animal production offers unique opportunities for significant progress in seafood production in the decades to come.

In view of these many challenges, considerably higher investment in basic research is urgently required to increase our knowledge of the biology of aquatic organisms and to develop more ecologically and economically sustainable farming practices with due consideration of socio-economic conditions.

FAO is concerned that the momentum of growth could taper off if governments and development agencies don’t adjust their policies to emerging challenges that threaten to thwart the sector’s future growth. As major challenges, we mention the lack of investment capital for small producers in the developing world, shortages of land and freshwater or related resource conflicts with other sectors, rising energy costs, environmental impacts and questions of product safety. Too few species are domesticated – the result of this being that the benefits of working with selective breeds remain an illusion. Big disease losses continue to occur; the limited knowledge of life histories affects the ability to apply appropriate preventive measures, and there is a continued dependence on fishmeal and fish oil in feed formulations.

Species selection was mostly based on business opportunities rather than their dietary needs, i.e. several aquaculture species are high in the food chain and as predators have high dietary needs for animal proteins. The fast expansion of aquaculture could not cope with the limited fishmeal and fish oil resources available from capture fisheries, and as a result, the sector is in high need of alternative protein sources. Furthermore, regional concentrations of monoculture practices resulted in significant environmental impacts, including water quality deterioration and pathogen and escapee impacts on local fauna, etc.

By the late 1960s, modern "business" aquaculture had evolved, initially in Japan and later in Europe and the United States of America, when the reproductive biology and controlled larviculture of a few high-market-value species could be practiced and intensive monoculture on-growing practices were developed. This soon resulted in a number of success stories, with the intensive culture of temperate species occurring first (e.g. salmon, trout, catfish) and as of the 1980s, with species grown in tropical and subtropical conditions (e.g. seabass, seabream, penaeid shrimps, oysters, clams, seaweeds). This monoculture practice has also been introduced in several Asian countries with Pangasius, tilapia, etc. Farm consolidation and vertical integration of production, often on a contract basis with small farmers, is in full progress in the West as well as the East.

Close to 80 percent of all farmed seaweed, fish and shellfish is produced in the Asia-Pacific region, the region with the longest tradition in aquaculture. In fact, artisanal farming practices developed empirically, and most of the production today is dominated by small-holder practices involving many millions of farmers. In sharp contrast with current developments in modern aquaculture in the West, Asian farming practices are mainly based on species low in the food chain and are often integrated in natural ecosystems, practicing maximal nutrient recycling in polyculture systems that take maximal benefit of all possible levels in the food web, e.g. co-farming of various species of fish, shellfish and plants occupying different niches in the ecosystem and benefiting from each other directly or indirectly for food, shelter, etc. Several forms of integrated farming of aquatic and terrestrial plants as well as animals are still popular practice in many Asian countries, e.g. rice-cum-fish culture, pig/duck/chicken-cum-fish farming.

The continued stagnation in wild catches, coupled with a growing world population and increasing per capita consumption of fish puts a lot of pressure on aquaculture, i.e. FAO estimates that ten years from now an additional 28 million tonnes of aquatic food will be required on an annual basis just to maintain current levels of consumption.
According to the latest FAO statistics, aquaculture is still the fastest growing food production sector in the world, i.e. in 2008 farmed seafood – fish and shellfish – represented about 53 million tonnes, up more than 20 million tonnes from a decade ago. Today farmed product represents about 50 percent of the seafood consumed by humans.