The Blue Food Revolution / Sarah Simpson

New fish farms far out at sea and cleaner factories near the coast could provide humanity with a large amount of vital protein 

Neil Sims takes care of his animals like a dedicated farmer. But instead of riding a horse, like the Australian shepherds he grew up with, Sims dons a mask and snorkel to herd his herd: 480,000 silver fish running in a pen, 800 meters from Kona Beach on the Big Island of Hawaii.

Sims' farm, hidden beneath the waves, is one of 20 establishments in the world trying to take advantage of the world's last great agricultural frontier: the ocean. Their location far from the coast is an advantage compared to the usual fish farms that contain fleets of cages hugging the coastline. Many of the old-style fish farms, notorious for their ugliness and pollution, spew out vast amounts of fish feces and food scraps, muddying the shallow waters by the shore, causing dangerous algae to flourish and killing every living thing under the cages. At sites far from the coast, such as Kona Blue Water Farms, pollution is not a problem, says Sims. The seven submerged cages, each the size of a school gymnasium, are anchored between fast currents that carry away the secretions, which dissolve to harmless levels in the open water.

Instead of simply believing Sims, I stuck my feet into rubber fins, put on a mask and snorkel, stood on the edge of his small service boat and jumped into the water. The cage, two cones close together at the base, appears from the water to glow like a huge Chinese lamp with vibrating streaks of sunlight and shimmering rushing fish. The touch of the stretched material on the cage frame is more reminiscent of a fence than a net. The synthetic sheets ensure that the hungry sharks stay out, and that the masses of swarming fish, a local wild strain of yellowtail tuna that Blue buys at home, stay in.

Why Yolo-Tail? Wild populations of tuna are dwindling, and the price of sushi-quality yellowtail is high. Sims and his colleague Dale Sarver, both marine biologists, founded Kona Blue in 2001 to raise sought-after fish in a sustainable way. But the company's methods can be applied to fish farming of all kinds, and we may still need them. The world's population, which currently stands at 6.9 billion, is expected to grow to 9.3 billion by 2050, and with rising living standards, people tend to eat more meat and seafood. However, the amount of fish caught in the various fishing areas of the world did not increase, and even decreased in the last decade. Raising cows, pigs, chickens and other animals requires vast areas and huge amounts of fresh water, fuels that pollute the air and fertilizers that wash into rivers and oceans and choke them with algae.

Where does the protein that humans need come from? The answer may well come from fish farms far from the coast - if they can operate efficiently, and from farms close to the coast - if a way is found to clean them.

Credit: Illustration by Dan Foley

Yellowtail fish in cages grow more efficiently than wild fish because they don't expend energy hunting and evading predators.

Clean is good

Some scientists believe that in order to feed the world, the protein production we produce from animals must be transferred to the sea. But in order for the blue revolution to be able to fulfill this important role, it must be carried out in such a way that it does not harm the environment, and it must spread the word about its benefits both among the public and among the policy makers, who can encourage or suppress its spread.

In the past, there was indeed room for condemnation. At the beginning of the fish farming in cages by the coast, about 30 years ago, things were done incorrectly - neither in terms of the environment nor in terms of the long-term existence of the industry. The waste was only one of the problems. Shrimp farmers in Southeast Asia and Mexico have cut down mangrove forests along the coasts to create shrimp ponds. In the salmon farms in Europe and America, the fish were overcrowded and therefore prone to the spread of diseases and parasites. Fish that escaped from the cages spread diseases among the wild species. And worse, the aquaculture industry caused (and is still causing) a considerable decrease in the mass of the fish. Collected wild fish - small and cheap species that humans do not eat, but which the large wild fish feed on - are caught in huge quantities and ground up for food for the larger, tastier and more expensive fish raised on farms.

Such harm to fish and the environment is not good for business, and the industry has sought and found innovative solutions. Kona Blue's solution, to place the farm in strong currents at a great distance from the coast, is one of the examples. Other companies are starting to grow seaweed and other sea creatures next to the fish cages, such as molluscs of various kinds, which filter their food from the water and swallow the waste. In the industry as a whole, including in freshwater ponds, improvements in the treatment routine for the animals and in the feed mixtures reduce diseases and accelerate the growth of fish, at the same time as reducing the amount of small fish in their diet. Still, it will surely take a long time before environmental activists remove caged fish from the "do not buy" lists.

There are pioneers who think and try bolder steps than this. The border of the territorial waters of a country is 370 kilometers from its shores - an extensive open area that has not yet been used for the deliberate production of food. Around the USA, the area of ​​this area is about one million square kilometers. Submerged fish cages, driven by large propellers, would be able to migrate with steady ocean currents, returning months later to their starting points or a distant destination and delivering fresh fish to market.

In late 2008, off the coast of Puerto Rico, marine engineer Clifford Gowdy conducted the first experiment of its kind in the world: a self-propelled submerged fish cage. The cage, a geodesic sphere about 20 meters in diameter, was equipped with a pair of 2.5 meter propellers, and it turned out to be remarkably easy to maneuver. Gowdy, former director of the Sea Grant Center for Offshore Aquaculture Engineering at the Massachusetts Institute of Technology (MIT), envisions dozens of farms migrating in the steady current out of the Caribbean Sea on a nine-month cycle.

Binge eating

The most difficult problem to solve in aquaculture is the use of small wild fish to feed the caged fish. (The small fish are not raised, because there is already an old industry that catches and processes them into fishmeal and oil). The issue of feed is sharpened when Sims and I board the old US Army transport ship, which has undergone a sophisticated conversion into a feed barge. The waves of the sea shake me sideways on my way to the bow, reminding me of a bumpy ride in a van years ago through frozen Missouri ashes to bring hay to my cousin's cows. The memory of the dry, fragrant grass is erased as I stick my hand into the 1,000 kilogram sack that opens on the deck and scoop up the brown, greasy food. The tablets look like small dog food, but smell like an empty can of anchovies.

Not surprising: 30% of Kona Blue's food is ground Peruvian anchovies. Sims explains that yellowtail fish can live on vegetarian food, but then they won't be as tasty, and their meat won't contain all the fatty acids and amino acids that give them their great nutritional value. These acids come from fishmeal and fish oil, and that's the problem. "We are criticized because we kill fish to raise fish," says Sims. The same criticism is leveled at salmon farming, which is done in cages close to the coast.

Opponents fear that increasing demand for caged fish will wipe out the wild population of anchovies, sardines and other small fish. In the past, most fishmeal was used as feed for pigs and chickens, but today aquaculture consumes 68% of fishmeal. However, it should be noted that consumption has decreased with the development of advanced food formulas. When Kona Blue started growing yellowtail in 2005, her food tablets contained 80% anchovies. At the beginning of 2008, its share decreased to 30%, without impairing the taste or nutritional value, according to Sims, with increasing the concentration of soy flour and adding chicken oil, which is a byproduct of poultry processing. The food tablets are a big improvement over the losing practice of throwing whole sardines into the fish cages. Unfortunately, this wasteful practice is still very common among many breeders.

The more enlightened breeders aim to reach a balance, so that the amount of fish in the feed will be equal in weight to the amount of fish for food. The tilapia and catfish breeders in fresh water managed to reach this magic ratio, but not so the breeders in the sea. In Kona Blue, with 70% vegetable protein and oil in the feed, the ratio is now 1.6-2 kilograms of anchovies per kilogram of tuna. In the salmon industry, the average is around 3 kilograms. To break even, the industry will have to lower the ratio. And yet, fish in cages consume much less than their counterparts in the wild: a free-ranging tuna fish consumes up to 100 kilograms of food, all fish, per kilogram of body weight during its lifetime.

The pressure to reduce sardine and anchovy fishing will increase as the number of fish farms increases. Aquaculture is the food production sector whose growth is the fastest in the world: 7.5% per year since 1994. At this rate, fishmeal and fish oil resources may disappear by 2040. The ultimate goal is therefore to completely remove the wild fish component from the cage diet within about a decade, says marine biologist Carlos M. Duarte, director of the "International Laboratory for Global Change" at the Spanish Council for Scientific Research in Mallorca.

The breakthrough that may help realize this goal is the extraction of DHA, an important omega-3 fatty acid, from microscopic algae. This could replace some of the small fish in food. This fatty acid, extracted from algae, is already used today to enrich baby food, milk and juice, and at Advanced BioNutrition, in Columbia, Maryland, it is being tested as an additive to fish food. Recently, researchers in Australia succeeded in extracting DHA from land plants. Duarte believes that the tough competition for agricultural land and fresh water will mean that fish farmers will eventually have to remove soy, chicken oil and other terrestrial products from the menu, and feed their flocks with zooplankton and algae, which are very easy to grow. (Algae is already about a quarter of the value of all aquaculture.)

Despite the improvements that have been introduced in raising fish in cages at sea, environmental activists and university researchers are still raining crossfire on the industry. Marine ecologist Jeremy Jackson of the Scripps Institution of Oceanography says he is "furiously opposed" to the aquaculture of predatory fish and shrimp (shrimp) - basically, any fish that people like to eat in sashimi form. He claims that this activity is "ecologically catastrophic" because of the pressure it exerts on the wild fish, and demands that it be defined as "illegal".

Better than cattle

Jackson's argument, echoed by other critics, is that the risk of collapsing the already overexploited stocking fish populations is too great to justify producing a luxury food most of the world will never get to taste. It is better to eat the sardines and the vegetarian anchovies directly instead of raising the super carnivores on them.

Sims agrees that it should fish Lower on the food chain, but does not agree that it should eat lower. "Let's be realistic," he says. “I eat anchovies on my pizza, but I can't get anyone in my family to eat anchovies. If you can get a kilogram of sushi from a kilogram of anchovies, why not give people what they want to eat?"

Some reject eating fish at all - from the wild or from cages - on the grounds that the planet and humanity would be healthier if people ate more plants. But, for now we don't see a mass influx to vegetarianism. Most people are eating more meat, especially with growing wealth and westernization in developing countries. The World Health Organization predicts a 25% increase in meat consumption by 2050. Even if per capita consumption does not increase, pasture and forage areas (according to the current yield level) will have to increase by 50% to 70% to meet the needs.

This reality calls for a comparison that is rarely made: fish farming versus cattle farming. Fish farming, if done correctly, could provide the necessary amount of protein for the world while minimally expanding the breeding of animals for food on land and reducing the heavy environmental cost.

Terrestrial agriculture has already changed 40% of the Earth's face, and after 10,000 years to mend its ways, it is still plagued with serious problems. Cattle eat huge amounts of heavily fertilized plants, and pig and poultry farms are known polluters. The wastelands below the coastal fish cages are nothing compared to the wastelands created by agricultural fertilizer drift in the Gulf of Mexico, the Black Sea and many other places, and their damage is nowhere near that of the toxic algal blooms caused by pig farm effluents into the Chesapeake Bay.

A growing number of scientists are beginning to compare the environmental impacts of different protein production systems so that society can "focus its energies on effectively solving the most difficult problems," writes Kenneth M. Brooks, an independent marine environmental consultant in Fort Townsend, Washington. According to Brooks' estimate, raising Angus cows requires an area of ​​prime pasture land 4,400 times greater than the seabed area needed to obtain an equivalent weight of caged Atlantic salmon fillets. Moreover, the ecosystem under the salmon farm can be restored in less than ten years, while it will take several hundred years for pasture land to grow back and grow a mature forest like the one that was cut down for the establishment of a cattle farm.

An even more compelling reason to grow our protein in the sea is to reduce the use of fresh water. According to Duarte, animal meat products are 3.5% of the world's food production, but they consume 45% of the water for agriculture. He emphasizes that with the transfer of the bulk of protein production to the ocean, "terrestrial agriculture will be able to expand without exceeding the current level of water utilization."

The collection and transport of soybean meal and chicken oil and feeding the fish also consume energy and pollute the air. Remote farms in the middle of the sea consume more fuel and emit more air pollution, but both types of farms are better than fishing ships. The only way to profitability in deep sea farms now is to raise expensive fish, but costs can come down: some experimental farms are already raising mussels in the ocean at competitive costs.

Environmental excellence

If more fish on the plate is the answer to the global demand for protein, why not fish more fish directly? Because many fishing areas are already being exploited to the maximum, while the world's population, as well as the demand for fish per capita, is skyrocketing. In North America, for example, many listen to the advice of health experts to eat fish to reduce the risk of heart attack and improve brain function.

In addition, fishing vessels consume fuel and emit greenhouse gases and pollutants in huge quantities. Conventional methods of indiscriminate fishing, such as giant nets and seabed dredging, for example, kill millions of animals. Studies show that at least half of the sea creatures killed in this way are thrown back into the sea because they are too small, or because the cap has filled up, or because the fishermen do not want them. All too often, this byproduct is thrown overboard when most of it is already dead. Aquaculture completely prevents this waste: "The breeders only discard the fish in the cages," says Sims.

Gaudi illuminates another matter: raising fish is much more efficient than catching them. Fish in cages convert food into meat at a much higher efficiency than their species in the wild. The fish in the wild expend enormous amounts of energy as they hunt for their food, avoid predators, seek mates and reproduce. Caged fish have an easy life in comparison, and most of their food is used for growth.

Kona Blue's hilotail fish and most cage-raised salmon are harvested when they are one to three years old, one-third the age of the large tuna fish sought after for sushi. Their young age also means that caged fish have less time to accumulate mercury and other pollutants that make adult swordfish and tuna potentially dangerous to health.

Caged fish already occupy 47% of the global consumption of sea produce, compared to 9% in 1980. Experts predict that their rate will rise to 62% of the total protein supply by 2050. "There is no doubt that aquaculture is a big thing, and it is not going to disappear. Those who oppose it simply don't get it," says Jose Vialon, director of the Aquaculture Program at the World Wildlife Fund. It is wrong to look at the problems created by aquaculture without comparing them to problems created by other forms of food production. True, aquaculture is changing nature, and no amount of improvement will eliminate all problems. But all food production systems take a toll on the environment, and wild fishing and raising cattle, pigs and poultry are among the worst systems.

In order to encourage responsible behavior among the breeders, and to distinguish between the clean fish farms and the big polluters, the World Wildlife Fund, in collaboration with other organizations, established the Council for the Supervision of Aquaculture, whose role is to set global standards for responsible procedures and to hire independent inspectors to grant licenses to the operating farms according to the standards. The Council believes that it is possible to bring about the great change by motivating the largest fish retailers in the world, one hundred to two hundred in number, to buy fish from licensed farms only, and not from small and dubious producers who are in the field in their thousands.

The Director of Aquaculture at the Ocean Resources Conservation Authority, George Leonard, agrees that the power of such a licensing program is to encourage marine farmers to adopt sound work practices. As in any global industry, he says, there will always be cheap and unscrupulous suppliers. Establishing standards will require American farmers to behave responsibly "without robbing them of their ability to compete."

This is an important matter. Only five of the 20 offshore marine farms are in US territorial waters. Gowdy believes that more entrepreneurs will join the fish farm industry if the US prepares a licensing system for its federal waters, from 5 kilometers offshore to the 370 kilometer limit. "No investor will enter a factory in the US without legislation that will guarantee his lease rights," says Gowdy. All American farms are within the five-mile strip controlled by the states, and only a few states, such as Hawaii, allow this. California has not yet given permits, despite the government's estimate that a sustainable industry of fish farming far from the coast in one percent of the ocean area belonging to the state could generate an income of up to one billion dollars per year.

The protein policy

For the fish farming industry to grow sustainably, appropriate policies and a more level playing field are needed. In the US at the moment, substantial government fuel subsidies encourage activities such as casting giant nets and dredging the seabed, even though it is already known that they destroy sea creatures en masse and cause enormous damage to the seabed. Subsidies for land farms maintain good profitability in raising cattle, pigs and poultry. Powerful agricultural lobbies continue to block attempts to reduce, for example, the runoff of nitrogen-rich fertilizers into the Mississippi River. "Almost none of these traditional food industries have been subjected to as much scrutiny as aquaculture," says Brooks. The public accepts the conversion of the land to human needs, but insists that the oceans should remain wild, even if this lack of balance is not necessarily the best plan for feeding the world.

Policy shifts at the federal and regional levels in the US may soon open federal waters to aquaculture. In January 2009, the Gulf of Mexico Fisheries Management Council voted in favor of an unprecedented plan to allow offshore aquaculture within its jurisdiction, subject to approval from higher levels within the US National Oceanic and Atmospheric Administration (NOAA). The administration will examine the plan only after formulating the new national policy regarding aquaculture, which refers to all forms of industry, and will certainly include guidelines for the development of a consistent nationwide framework for regulating commercial activities. "We don't want the Blue Revolution to repeat the mistakes of the Green Revolution," says NOAA Administrator Jane Lobchenko. "This is too important to be wrong, and there are so many ways to be wrong."

Due to the ever-increasing demand, our society has to make decisions about how and where to produce the protein it needs. "One of my goals was to bring us to a situation where, when people ask for security in the availability of food, they will not only mean grains and cattle but also fish farms and aquaculture," says Lobchenko. Duarte suggests that we take the pressure off the land a little and turn to the sea, where we have the opportunity to establish aquaculture in the right way, so that we don't look back in 40 years and be crippled for a sin.

As for Neil Sims' part in the blue food revolution, he is courting technology companies and looking for upgrades. Tools like robotic net cleaners, automatic feeders and satellite video cameras to monitor fish health and damage to cages will help Kona Blue manage its farms remotely. "Not just so we can raise more fish in the ocean," says Sims. "So we can raise more fish better."

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in brief

Meat consumption in the world is increasing, but its production requires huge amounts of energy and water, and involves pollutants. At the same time, the natural fishing areas are dwindling. Aquaculture may become the main source of protein for humans.

Fish farming already provides half of the world's fish production. Most of it is done along the coasts and causes severe pollution.

Large cages anchored to the seabed far from shore are a cleaner option. Such farms, along with other new forms of aquaculture and improvements in near-shore factories, could expand aquaculture considerably.

It is not yet clear whether these approaches can be sustainable and profitable in the long term.

How It Works

Five ways to grow food in the sea

Marine fish farming is mostly done in tanks on the beach or in cages in the water near the shore, but the tendency today is to anchor cages at a greater distance in the sea. At least one attempt was made with a mobile cage prototype, submerged in water in the open ocean and powered by propellers. Entrepreneurs also grow algae and shellfish on cables next to coastal cages, and it is possible that this will also be used for cleaning around wind turbines at sea.

Cages in the open ocean

In the future, propeller-driven submerged cages will move with known ocean currents, arriving at distant destinations months later, when the fish are mature. The food will be stored in the central mast, and the feeding will be done using machines.

Cages anchored in the middle of the sea

Young fish are placed in a stationary cage the size of a sports hall. The central mast is filled with water, and the cage sinks until the fish reach maturity. The feeding is done from a hand or spoken, through pipes. The currents sweep away the debris. To collect the fish and clean up the cage.

Turbine collars

Oysters and algae easily attach to synthetic cables and grow naturally. Such cables can be wrapped around turbines in offshore wind farms to increase profitability and reduce competition for areas in the open sea.

Cages on the beach

All sea fish for breeding are hatched in tanks on land. Many of them are transferred to cages at sea when they reach a suitable size, but there are some new attempts to grow them until they are collected in tanks on land, where it is easier to control pollutants and diseases, and there is no problem of fish escaping from the cages.

Cages by the beach

Thick mesh cages are relatively easy to anchor and maintain. Automatic feeding systems can minimize food waste, using infrared sensors located on the seabed that turn off the system when they notice falling food tablets. Algae and molluscs that feed on the fish waste, which will be placed downstream from the cage, will reduce pollution and add to income. You can also place trays of waste-eating creatures, such as sea urchins, under the cages.

More on the subject

The State of World Fisheries and Aquaculture 2008. FAO, 2009.

Will the Oceans Help Feed Humanity? Carlos M. Duarte et al. in BioScience, Vol. 59, no. 11, pages 967-976; December 2009.

Sustainability and Global Seafood. Martin D. Smith et al. in Science, Vol. 327, pages 784-786; February 12, 2010.

Will Farmed Fish Feed the World? An analysis from the Worldwatch Institute. www.worldwatch.org/node/5883

Fish Farm Slideshow: ScientificAmerican.com/feb2011/simpson

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