When we look at the food system, how we feed seven billion people today, and how we plan to feed nine billion by 2050, the conversation usually focuses on the extraordinary progress made to date in crops, grains, and livestock production. But that’s only part of the story. Not every part of the food chain has grown and adapted to increased demand, and not every part of the food system is poised to scale along with human population growth—at least not yet. So what are these not-quite-success stories?
For one example, just look at seafood.
Worldwide, some 80 million tons of fish are hauled from the oceans annually. Fish is delicious, healthy, and an important part of many diets, historically and today. But there’s a problem with wild caught seafood: fish stocks—the population of fish in the ocean—aren’t growing. At least, not at the rate human populations are. The UN Food and Organization (FAO) estimates that under the best-cast management scenario, the size of the worldwide wild-caught fish harvest can rise about another 16.5 million tons—to somewhere between 90-100 million tons, total, worldwide.
And that’s it. That’s the maximum global production capacity of the oceans. And that’s the best-case scenario maximum, where currently in-danger and depleted fish stocks are able to rebound to healthy population levels, and harvested sustainability from thereon out.
That’s a total, possible output growth of 20 percent. For scale, by 2050, the human population will have grown another 30 percent.
So what happens then; what happens when unyielding demand profoundly overtakes supply? You innovate, and start raising fish like livestock.
Aquaculture, as the practice is called, is diverse, well-established, and, unlike wild fish stocks, can grow—aquaculture has grown 14-fold since 1980; it overtook beef production by weight at 66 million tons in 2012; and is on track to overtake wild-caught seafood in 2030 at 90 million tons produced annually.
There are a lot of advantages to aquaculture, both over wild-caught fish, and even over livestock. Fish, for example, expend a lot less energy than livestock: they’re cold blooded, and thanks to their watery environment, they don’t have to fight gravity when they move around. These sound like a small details, but they add up: all that energy swine and cattle and poultry use keeping warm and moving around is energy fish expend, instead, growing. The “feed conversion ratio,” the metric that measures how much feed is needed to grow livestock—a ratio of inputs to outputs—speaks for itself: it takes 6.8 lbs. of feed to produce a pound of beef; for swine, 2.9 lbs. of feed to grow pound of pork. For chicken, this ratio is as low as 1.7 to 1.
If you’re thinking critically about how in the world we’ll produce enough protein to meet the demands of 9 billion people, a 1.1-to-1 feed conversion ratio should have definitely piqued your interest—but there’s a catch.
Not all forms of aquaculture produce these kinds of results, nor are all forms of aquaculture independent of ocean fishing. The most commercially valuable fish, like salmon or cobia, are predators, and many of their more valuable properties, like high omega-3 content, come from their position near the top of the food chain. Because of this, they need to be fed fishmeal made from wild-caught seafood, and have their diets supplemented with fish oil, usually derived from wild-caught anchovies and sardines. These ocean-sourced feed inputs account for only around 30 percent of farm-raised salmon’s diet, but already, aquaculture consumes nearly 70 percent of the global fishmeal supply, and 90 percent of the world’s fish oil supply: necessary inputs whose supplies are constrained by the same fundamentally low growth ceiling that constrains all ocean-sourced seafood.
Omnivorous fish, like catfish, tilapia—even trout—are not necessarily constrained by these issues. Scaling production of these fish in a truly sustainable way, however, means ensuring their feed contains efficient sources of protein divorced from ocean-sourced inputs.
Maybe a source of protein fish naturally eat?
Insects could produce protein for fish feed at a much lower environmental cost than fishmeal or even soy, the most common ingredients in fish food today. Insects can be raised on manure, offal, discarded brewery grains, and even food waste—itself an important resource re-capture mechanism. Insects are comparable to soy in protein content, and just one hectare of land can product around 150 tons of insect protein a year—150 times more protein per hectare of land than soy can produce.
And, as fish feed, insects work quite well. A 2014 review of insect feeding trials by the FAO found that fish common to aquaculture, like tilapia, could safely have between 25 to 100 percent of the soymeal or fishmeal in their diets replaced with insectmeal with no negative consequences to fish production. Even when cooked, the fish showed no changes to aroma, taste, or texture.
Today, researchers, entrepreneurs, and investors are looking to perfect a scalable, low-cost, insect-based feed for aquaculture and even poultry (another livestock that naturally eats insects). And while the industry is undeniably still in its infancy, if you’re serious about finding sustainable protein solutions to feed a world with an extra two billion people, you have to find holistic ways to redesign how we put food on the table. And as far as innovative solutions go, massively shrinking the environmental footprint of protein through investments in insect-fed aquaculture seems like a good step in the right direction.