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80 Million Coming for Dinner: What to Serve?

Buckminster Fuller called our planet ‘Spaceship Earth,’ because it carries a finite amount of air, water and natural resources without any chance to resupply the passengers—us!  However, unlike most spacecraft, nearly 80 million new passengers join our ship every year.  Hopefully, most of these annual newborns aren’t destined for poverty, but will join a growing middle class scheduled to reach 5 billion by 2040, when our global population will have grown from today’s 7 billion to 9 billion.  Our 2 billion new passengers---and everyone else---will need and want more of everything, including food.  Where will we get it?

The good news is that we can provide the quality nutrition our children and their children will need if we simply use our natural resources more strategically.  There are a number of options for increasing food and protein production.  

Some can come from advances in more sustainable agriculture, though balance must be maintained among areas used for cropland, forests, pasture, human development, water management and biological conservation.   

Some may come from fresh water, both from aquatic wild catch and aquaculture of fish and shellfish, provided that climate change, dams, habitat destruction and poor development practices don’t reduce or pollute water supplies and overfishing doesn’t deplete wild populations.  Most of the world’s water and accessible lakes, ponds and rivers are already heavily used, so how much more they can sustainably contribute to human food supplies is an open question.

Some may come from foods synthesized from algae, bacteria, fungi or other microbes or chemicals.

By Alan Hughes (Image:France_Oyster_Harvest.jpg) [GFDL (http://www.gnu.org/copyleft/fdl.html), CC-BY-SA-3.0 (http://creativecommons.org/licenses/by-sa/3.0/) or CC-BY-SA-2.5-2.0-1.0 (http://creativecommons.org/licenses/by-sa/2.5-2.0-1.0)], via Wikimedia Commons

That leaves only one other place to look: the ocean.  Food from the ocean is attractive, because a single 150 g (5 oz) serving of seafood can provide 60% of a person’s daily need for protein, and the World Bank estimates that the world will need to produce 70% more protein than we do today.  Another seafood benefit is that many finfish provide the omega fatty acids needed for healthy brain development.

But the outlook for more food from the ocean is mixed.  Despite increased effort, wild catch has languished at about 80 million metric tons since 1990.  FAO and the World Bank estimated that better management of marine fisheries -reducing fishing pressure, improving enforcement of regulations and eliminating illegal and unregulated fishing- could increase the value of fisheries catches by $50 billion annually.  Reducing bycatch and habitat-destructive fishing methods could further benefit wild populations and harvests as well as biodiversity.

All that will take time.  Meanwhile, mariculture -farming seafood in coastal waters or the open ocean- could quickly increase in many places.  For the past four decades fish farming has been the fastest growing food sector –growing much faster than cereal, beef or poultry— and mariculture already produces about 17% of the food that humans consume directly, only about one-third of that produced by fresh water aquaculture, but with perhaps more potential for growth.    

How much more can mariculture contribute?  We don’t yet know.  The answer will require fine scale data on how much suitable habitat each country has, the range of environmental conditions in each location, which species might grow successfully and how much each one might sustainably produce under those conditions.  Information about competing (or synergistic) use options for those areas would also be needed.  

Learning all that will take a long time, but the Index’s low global score for mariculture, 26 out of 100, and the fact that 96% of mariculture production comes from only 15 of the world’s 151 coastal nations -90% of it from Asia, with nearly 50% of the entire world’s production from China alone- suggests that many countries could produce more. 

The Ocean Health Index evaluates mariculture not only by how many metric tons are produced, but also on how sustainably that food is raised.  Six countries scored 100: China, Chile, Ecuador, Faeroe Islands, New Zealand, Norway and Chile, indicating that they are sustainably producing about as much as could be expected.  Canada (93), Thailand (92), France (73), Ireland (69), Spain (66), Iceland (63), South Korea (57) and Belize (51) also performed reasonably well.  But 77 countries scored 10 or below, so large global gains could possibly come from further development or improved management of mariculture.

Figure 1.1: Blue Frontiers, Managing the Environmental Costs of Aquaculture Report, p. 10

Making aquaculture more environmentally sustainable is a fast-growing science.  Blue Frontiers, Managing the environmental costs of aquaculture reports that farming fish is advantageous because they convert food to protein more efficiently than cows, sheep, pigs or most other livestock do.

Table 3.1 Blue Frontiers, Managing the Environmental Costs of Aquaculture Report, p. 45

However, there are still environmental costs, especially for the larger more economically valuable finfish, such as salmon, eels, sea bass, grouper and others, that are carnivorous and have mostly been fed with fish pellets made from smaller ocean fish.  The Sea Around Us Project recently reported that growers have shifted more of their production to such high value species and away from lower-priced species that eat algae or detritus.  Not only do the new species entail higher ecological costs, but they also cost more to produce, sell for higher prices and are only accessible to the middle class.  Low income populations cannot afford them, so the only way they will help feed the world’s growing population is if that population is not entrapped by poverty.

Table 2.1: Blue Frontiers, Managing the Environmental Costs of Aquaculture Report, p. 17

The future expansion of mariculture will depend on how well countries develop and manage new production facilities and associated infrastructure, including whether diets can replace ocean fish with plant-based substitutes, reduce the use of pesticides, avoid pollution by wastes and nutrients and minimize use of non-native species or genotypes that could escape and become invasive.

The Ocean Health Index rewards mariculture that is sustainable.  Huge growth in production could result from expanding the most sustainable forms of fish farming to nations that need more protein to feed their own people, more jobs, and more exports to boost their economies.  Hopefully that will happen in time to feed the many young passengers joining our spaceship every day.