An article in GAA Advocate titled Calories count Aquaculture makes them truly add up recently piqued my interest. It was written by my friend Scott Nichols and he lays out with startling clarity the case for why we will soon be relying on aquaculture to feed humanity. Interested in the future of aquaculture or the problem of global food insecurity? Scott’s article is a must-read! Here are a few points to summarize:
Given current demographic trends, the world’s population is almost certain to grow by close to 2 billion people over the next 20 years. At the same time, much of this population is becoming wealthier. Shrinking poverty is obviously a good thing. This increased wealth is driving demand for a better diet, and in particular more protein. The question is, where is this protein going to come from?
Scott presents our current food situation succinctly: The agriculture system we rely on consumes almost 40% of the earth’s land. Another third of the earth’s surface is desert, mountains, frozen, or otherwise unsuitable for growing food. Half of what remains is in natural parks or reserves and transportation networks, housing, and industry occupy much of the rest. Scott’s point is - we can no longer expect to grow our food supply to meet future needs by increasing the acreage devoted to farming. The land is simply not there.
So, if we cannot look to the land for more food, what about the sea? Our planet is more than 70% ocean. We currently get one sixth of our protein from fish, half of which is wild-caught and the other half is farmed. Wild-caught fish populations are already at their tipping point, with 90% either at or above maximum sustainable harvest levels. Raising fish on farms, or aquaculture, is the only solution to dramatically increase food production for the sea. This makes intuitive sense. Just as farming increased land productivity by several orders of magnitude compared to hunting and gathering, farming the ocean should allow us to do the same.
Scott examines the economics of salmon farming and shows that a single acre of ocean devoted to salmon can provide 760 million calories of food. To put this in perspective, an acre of corn provide less than 16 million calories and an acre of land used to feed cattle will provide slightly over 1 million calories of useful protein. Wow!
Not only is a salmon farm 750x more productive in terms of calories than cattle farming, salmon are dramatically more efficient at converting feed into edible protein- a pound of salmon fillet requires less than one tenth the feed to produce as a pound of hamburger. Plus, a salmon farm is 3-dimensional so more animals can be grown in the same physical footprint.
More productive and more efficient? As Scott says, when it comes to how we are going to feed the world, aquaculture “is a big part of the answer and at the very center of a hopeful food future.”
But… because isn’t there always a ‘but’? In order for create a steady supply of fish to feed us, we first must find a way to feed them. Unlike cattle, poultry, and pigs, salmon and many of the other species we consume are carnivores- their natural diet is protein from smaller fish. In the early years of aquaculture this was not a problem because the standard aqua diet was based on fishmeal made from anchovies and other small pelagic species. But we now are harvesting these species up to their sustainable limit so for aquaculture to grow any further, we need alternatives to fishmeal.
Today the most common alternative is soy, but it’s an incomplete solution. Soy contains anti-nutritional factors that affect fish gut health and every acre of land devoted to soybeans for fish feed is subtracted from land for human consumption. That’s why companies like mine are looking to create novel proteins to replace fishmeal that are sustainable and at the same do not consume limited resources like farmland and water.
This is the direction our world is heading. We need to grow more food with less resources, while also maintaining our obligation of environmental stewardship. The scale of this challenge is so massive that there will be multiple winners among the companies producing fish meal alternatives. Single cell proteins like KnipBio Meal, protein from insect larvae, and other sources will all make significant contributions. It’s an exciting time to be working on one of the steepest challenges that lie ahead for us and I am grateful that Scott has presented it so eloquently.