Findings suggest that answers to the two questions raised at the beginning of the study, namely: (1) do individual countries have a "realistic" ambition to expand their aquaculture production and (2) is the sum of national forecasts likely to be compatible with projected increases in demand for food fish, are generally positive. Countries do wish to expand aquaculture output, and with some exceptions, their assumptions were realistic. The examination of national plans and strategies has provided unique insights into the ambition and commitment of governments to develop aquaculture, and most have appeared to endorse the sectors growth. National priorities for development, in particular with regard to the role of aquaculture to contribute to food security (often cited as one of the three reasons behind a countrys will to develop the sector, along with foreign exchange earnings and economic growth) was indicative of the realisation that aquaculture can be an innovative motor of growth with many additional benefits, whilst revealing growing concerns over over-exploitation of capture fisheries and the motivation to find alternatives to declining catches.
As for the second question, aggregation of national plans indicated that global forecasts underestimated the supply of fish food coming from aquaculture. Chinas future expansion is critical but using a modest 2 percent growth rate and without increases in food fish output from capture fisheries, results suggested that most of the demand projections would be met. Thus, aggregated country productions from aquaculture are expected to grow at an average annual growth rate of 4.5 percent over the period 2010 - 2030. From these findings, a conclusion, yet sanguine, may be that the aquaculture sector could replicate the expansion of agriculture. However, much depends on the realism of assumptions used to support projected targets, and countries formulating development plans for their aquaculture sector are encouraged to place a stronger emphasis on the rationale supporting their production forecasts. This is useful to improved sector development planning, at an international scale, and progress monitoring. Many factors affect the evolution of an activity like aquaculture and setting realistic production targets is a difficult task. The sector is susceptible to unforeseen shocks, meteorological, pathological or economic, when countries compete in marketing a commodity and expand their production simultaneously.
The level of accuracy of projections can only be assessed from the clarity and realism of the assumptions upon which they are based. The scrutiny of global projections requires explicit calculations and assumptions, which is not always the case for national aquaculture development plans. However, country plans and strategies reveal governments commitment to aquaculture development. From this perspective, national plans may be more informative than global forecasts to gauge where future production impulses will originate and what will shape future regional development trends.
Whilst macro projection models were based on commodity prices, per capita incomes, rates of population growth and landings from capture fisheries to estimate future supply, population density could be another factor to take into consideration in the setting of future production targets. This is suggested through the examples of Norway and Brazil, for which low population densities are seen as an asset to develop aquaculture further whilst avoiding conflicts over resource use and social opposition as typically encountered in more densely populated areas.
Because the gap between the estimated requirements from aquaculture in the next decades and what countries expected production was not large (even with a modest 2 percent annual growth for China), there may not be causes for immediate concern. Proper monitoring of aquaculture output should be maintained (or developed in countries where it is not yet in place). Technological developments could bring answers to immediate concerns over resource use: self-maintained offshore cages for intensive production (Mann, 2004), alleviating pressure from coastlines and inland waters, could significantly contribute to increases in aquaculture outputs and stabilisation of fish prices. However, potential for high profits from the farming of high-value marine finfish may be the prime motive behind this form of aquaculture and, in the case of the United States, it has been recommended that a moratorium is imposed on its development until "national aquaculture legislation is adopted and comprehensive, open and transparent regulations are finalized" (Belton et al., 2004) to avoid loopholes and conflicts over the use of coastal and offshore resources. Further concerns may be voiced over the market allocation of this type of production. Targeting developed country markets with high value fish exports is often a prime aim for many developing countries. Balancing both domestic needs for extra protein provision in low-income, food-deficit countries, and foreign income generation from the same activity is likely to involve delicate and politically-challenging decisions.
The third question addressed in this report dealt with planning processes. Appraisal of country plans and strategies revealed a generally weak planning process. This was mainly due to the fact that detailed information on the methodologies and procedures followed to complete a final plan were omitted or sketchily reported. This shortcoming would be easily fixed and the report has provided a planning framework of issues to address and which could be used directly by countries willing to develop or enhance their aquaculture sectors. Back-up by the application of the Delphi method as a consensus-building technique, not only would this greatly improve the quality of future plans, but would also enable an evaluation of their likelihood of success, as it has been demonstrated in the literature that transparency, legitimacy and agreement (reached through participation and consensus) were key to the success of a plan. It is also recommended that a more thorough assessment of past and present trends, at both national and international levels, are useful in determining more accurately areas with potential for development and in setting realistic production targets.
Beyond absolute increases in production, the sustainable development of aquaculture will depend on accurate and sensitive planning as issues of resources allocation for production and distribution of production will generate debate and require compromises. Much has been written on the concept of "sustainable development" and its irreconcilable goals of economic growth and development on one hand, and ecological (also social and economic) sustainability of the other - what Robinson (2004) has referred to as "squaring the circle". Aquaculture development could be seen in this sort of dilemma, and like the impossible mathematical problem, will require new tools to be solved. These new tools call for "a process by which [multiple conflicting objectives] can be expressed and evaluated, ultimately as a political act for any given community or jurisdiction". Planning will therefore be key to the sustainable development of aquaculture as it "encourages the development of new modes of public consultation and involvement intended to allow multiple views to be expressed and debated" (ibid, p. 382). Technical progress will undoubtedly play a crucial role in supporting aquaculture development, but its direction and (re)orientation will have to be constantly revisited through decision-making processes. By extension of Robinsons argument, the sustainability of aquaculture and it fulfilling worlds expectations as a supplier of fish for food security and as a vector of economic development is more likely to be "a political act", than a scientific achievement.