December 13, 2022

Are Projections of Aquaculture Growth Over-Optimistic?

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A recent paper in Frontiers in Marine Science (DOI:10.3389/fmars.2022.984354) by Sumaila et al. is entitled “Aquaculture over-optimism?”, with the deliberate inclusion of a question mark. The authors define this as “the belief that aquaculture can continue to grow at its recent rate or even faster, and therefore be able to meet global demand for fish single-handedly.” The authors claim that a media narrative feeds into the notion that aquaculture can feed the world.

To refute this narrative, the authors examined FAO time-series data and calculated the growth rate of aquaculture production, expressed as a five-year moving average. In general, the growth rate of aquaculture was about 10 percent in the 1990s, 6 percent in the 2000s, 4 percent in the 2010s and 2 percent in the 2020s. The authors calculated that the peak annual growth of aquaculture production was 14 percent and occurred in 1996.

Using percentage data can be highly misleading and this paper is not an exception. For a country or species starting at a low baseline, growth rate in production will be very high in the early years of development and then naturally decline as time goes on. Furthermore, there is no food production system that can perpetually sustain high growth rates. It is quite normal for food producing sectors to have grown rapidly in early years and then settle into relatively low, more sustainable growth rates. It is more important to look at absolute increases in production and not growth rates. A country that starts at a high baseline (pick any Asian country) and increases production by a relatively small percentage over time can add considerable production to global seafood supplies.

It is curious why the authors chose this approach. The real agenda of the paper is revealed in the statement that “An extreme form of as aquaculture over-optimism is the notion that we need not worry about sustaining wild fish stocks because we can meet the global need through farming.” Why take this approach of considering an extreme case? Who or what institution in aquaculture is saying that we should not work on sustaining wild fish stocks. There is no merit in pitting fisheries and aquaculture against each other. It is not an either/or, extreme-scenario, zero-sum game.

As is well known, fisheries production has been stagnant since the 1990s. Overfished stocks have increased from about 15 percent in 1980 to about 35 percent currently. Shouldn’t efforts be made to try to move fishing effort to more sustainable levels in those fisheries that would actually increase catches? In particular, capacity-enhancing subsidies that encourage overfishing should be removed or retargeted. The fact is that efforts to improve the management and sustainability of fisheries, and more importantly, to increase production, over the last few decades have on the whole failed. Pointing the finger at aquaculture by saying the industry is making promises that it can’t deliver is disingenuous and misplaced criticism.

There has always been a sense of optimism associated with aquaculture development given the vast potential in the early years of development in the 1970s and 1980s. Sure, there have been hyperbolic statements about aquaculture feeding the world, but it is true that for a time aquaculture was the fastest-growing food production sector in the world, mostly in Asia. And more recently, the message that aquaculture is a very efficient way to produce animal protein from the perspective of resource use has gained currency.

In the paper “Fish to 2030” published in 2015 (DOI:10.1080/13657305.2015.994240), the authors evaluate hypothetical scenarios based on various sets of plausible conditions to arrive at estimates of future aquaculture production. Such estimates for 2030 range from 93 to 116 million tons, seen as unattainable at current growth rates by Sunaila et al. In the Sunaila paper, they propose an extreme scenario “without wild fish,” concluding that aquaculture production growth rate would have to be three times the current production projected for 2030. It is unclear why this unrealistic scenario was even proposed. To meet projected future demand, it is clear that additional technical innovation are needed, management of any disease outbreaks would have to occur and other biophysical resource limitations would have to be overcome.

Sunaila et al. also discuss the geographical distribution of farmed fish production, making the point that fisheries resources are more uniformly distributed around the world, in contrast to aquaculture production that is concentrated in Asia (80 percent of total), and in China in particular (60 percent of total). The authors claim that the socioeconomic costs of over-optimistic aquaculture production scenarios could be “devastating” to low-income countries. Again, this assumes an extreme case of aquaculture providing all local fish production. Why?

If this article is intended to influence policy, it seems to have completely missed the mark. It’s hard to know what policy options the authors would favor. What would constitute a more realistic or less optimistic outlook of aquaculture’s future? Aquaculture production increases are generally flat outside of Asia, so much more work needs to be done to foster aquaculture development in those places, principally by creating a favorable enabling environment. Of course, also needed are ongoing technological innovation in genetic improvement programs, cost-effective and efficient feeds, disease management and biosecurity, and development of downstream parts of the value chain, including processing, marketing and distribution.
— John A. Hargreaves, Editor-in-Chief


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About John A. Hargreaves

World Aquaculture - Editor in Chief. Aquaculture expert with 40 years of experience in research, teaching, and development. Freelance consultant on commercial aquaculture and international development projects.