Photograph by Brooke Whatnall, Nat Geo Image Collection
Read Caption
Farmers cultivate seaweed from underwater seaweed farms off the coast of Bali.
Photograph by Brooke Whatnall, Nat Geo Image Collection

Make Way for Algae on Your Dinner Plate

Yum. Pond Scum.

According to many scientists, the next hot food on the family menu may be just that–pond scum.

More attractively known as microalgae, these tiny plants have been around for some three billion years. In fact, we couldn’t survive without them. Marine microalgae (phytoplankton) generate about half of the world’s oxygen and form the base of the marine food chain. In other words, if it weren’t for algae, we’d have no shrimp, sharks, salmon, mahi-mahi, tuna, or whales.

Worldwide, scientists guess, there are anywhere between 30,000 and a million species of algae, including both micro- and macro-versions, the latter commonly known as seaweeds. Microalgae can grow practically anywhere—in salt and fresh water, in ponds, lakes, rivers, streams, marshes, and bogs—even on the backs of alligators and the damp bark of trees. Back in the 1970s, the sudden appearance of green polar bears at the San Diego Zoo was found to be due to algae, colonizing the bears’ fur.

Though algae isn’t (yet) common chow in the United States, it’s been consumed by human beings for thousands of years. Seaweed is commonly eaten in Japan, China, and Korea; and figures in the native cuisines of Brittany, Wales, Iceland, and Ireland. Irish moss (Chondrus crispus)—actually a seaweed, commonly known as carrageen—is traditionally used in Irish soups and puddings. Algae’s lush battery of vitamins, minerals, nutrients, and antioxidants have led some to tout it as an up-and-coming superfood, in the same class as kale, blueberries, and green tea.

However, most research on microalgae in past decades has concentrated on its potential use as a biofuel, a possibility that to date hasn’t panned out. The problem, according to geneticist/entrepreneur Craig Venter—famed for being one of the first to sequence the human genome—is farming. No one has yet managed to grow oil-producing algae in sufficient quantities to challenge the fossil-fuel companies.

On the other hand, Venter insists, it’s doable. On average, commercial algae farms can turn out five to ten thousand gallons of oil an acre, as opposed to a mere 350 gallons of ethanol biofuel generated per acre by crops like corn.

To replace all the transportation fuels in the United States with biofuel from corn would take a cornfield three times the size of the continental U.S. To do the same with biofuel from algae would require a facility the size of the state of Maryland. While this sounds intimidating, new growth techniques coupled with new strains of algae genetically engineered to be ten to 100 times more productive, Venter argues, could potentially solve our fossil-fuel problems—though probably not anytime soon.

Algae as a sustainable form of food, on the other hand, may be a more readily-attainable goal. It’s relatively easy to grow, requiring only sunlight, seawater, and CO2, and it delivers a lot of bang for its buck, being 30 times more productive than soybeans and 50 times more productive than corn, all while using only one percent as much fresh water. Furthermore, unlike soybeans, corn, and cows, algae don’t demand fertile fields. Algae can flourish in manmade open ponds and pools in desert regions that are unusable for traditional crops. And algae grow fast, some doubling in less than 24 hours. While it can take six months to produce a kilogram of beef, comparable quantities of algae can be generated in a matter of days.

Algae also have an impressive protein content. While meat contains about 50 percent protein; soy, 40 percent, wheat 15-17 percent; and corn, 10 percent, algae boast a whopping 70 percent.

So how to eat this stuff? Luckily, as it turns out, there’s a lot that can be done with what most of us still view as unpromising green slime.

When the 2011 International Algae Competition invited algae enthusiasts, chefs, and foodies to create new dishes featuring algae, participants promptly invented dozens, among them algae pizza, sherbet, tofu, soup, quiche, pie, pancakes, “aquamole” dip, and a Harry-Potter-ish Spirulina candy dubbed Green Tongue because it turns consumers’ tongues bright green. According to Solazyme, a California-based company devoted to developing products from microalgae, algae can be incorporated into everything from crackers and snack bars to cereals, breads, sauces, and salad dressings. Some researchers suggest that algae may eventually serve as an inexpensive, healthy, and nutritious substitute for ingredients such as eggs, butter, and oils in packaged foods.

Algae may also be a viable substitute for environmentally-stressed food resources, such as the world’s dangerously declining fish population. Fish are a prime source of omega-3 fatty acids, essential for lowering blood triglycerides and protecting us from a range of ailments like heart disease and rheumatoid arthritis. Since fish, however, get their omega-3 fatty acids from a diet of algae (or a diet of crustaceans or other fish who eat algae), it might behoove us and the ocean’s threatened fisheries to go directly to the source and do the same.

Some institutions are also experimenting with algae as feed for livestock such as cattle, chickens, and pigs —which in turn would free up much-needed cropland to provide food for humans. At the moment, about 30 percent of arable land is devoted to animal feed; and 80 percent of America’s corn crop goes to livestock. (See The Plate’s Meat, Shmeat.) And by mid-century, it looks like we’re going to need all the cropland we can get.

By the year 2050, the world population is slated to leap to nine billion—the equivalent of adding an extra China and India to the already crowded globe. According to the United Nations, this means that we’ll have to nearly double our output of food. Most experts agree that traditional agriculture simply isn’t capable of doing the trick—which is why there’s now considerable effort going into technologies to efficiently grow algae at giant-size commercial scale.

Some predict that algae farms may be up and running by 2025.