It is rare for a farmer to appreciate the predators that eat the animals he raises. But Miguel Medialdea is hardly an ordinary farmer. Looking out on to the carpet of flamingos that covers one of the lagoons that make up Veta la Palma, the fish farm in southern Spain where he is biologist, Medialdea shrugs. "They take about 20% of our annuel yield," he says, pointing at a blush-colored bird as it scoops up a sea bass. "But that just shows the whole system is working."
Working, indeed. Located on an island in the Guadalquivir river, 10 miles (16km) inland from the Atlantic, Veta la Palma produces 1,200 tons of sea bass, bream, red mullet and shrimp each year. Yet unlike most of the world's fish farms, it does so not by interfering with nature, but by improving upon it. "Veta la Palma raises fish sustainably and promotes the conservation of birdlife at the same time," says Daniel Lee, best practices director for the U.S.-based Global Aquaculture Alliance. "I've never seen anything quite like it."
With wild fish stocks declining precipitously around the globe, thanks to overfishing and climate change, aquaculture has emerged as perhaps the only viable way to satisfy the world's appetite for fish fingers and maki rolls. In the next few years, consumption of farm-raised fish will surpass that caught in the wild for the first time, according to the United Nations Food and Agriculture Organization. But most fish farms even ones heralded as "sustainable" create as many problems as they solve, from fecal contamination to the threat that escaped cultivated fish pose to the gene pool of their wild cousins. (See pictures of tuna fishing.)
Veta la Palama is different. In 1982, the family that owns the Spanish food conglomerate Hisaparroz bought wetlands that had been drained for cattle-farming and reflooded them. "They used the same channels built originally to empty water into the Atlantic," explains Medialdea. "Just reversed the flow." Today, that neat little feat of engineering allows the tides to sweep in estuary water, which a pumping station distributes throughout the farm's 45 ponds. Because it comes directly from the ocean, that water teems with microalgae and tiny translucent shrimp, which provide natural food for the fish that Veta la Palma raises.
By hewing as closely as possible to nature, the farm avoids many of the problems that that plague other aquaculture projects. Low density roughly 9 lb. (4 kg) of fish to every 35 cu. ft. (1 cu m) of water helps keep the fish free of parasites (the farm loses only 0.5% of its annual yield to them). And the abundant plant life circling each pond acts as a filter, cleansing the water of nitrogen and phosphates.
"We call it the pata negra of sea bass," says Hisparroz president Luis Contreras, referring to the highly prized Spanish ham made from Ibérico pigs. Like those pigs, Veta la Palma's fish not only forage for most of their own food (shrimp instead of acorns) but enjoy longer lives than their industrial counterparts. Most sea bass is harvested when it's big enough to fill a plate about 14 oz. (400 g). But at Veta la Palma, they wait until each fish weighs 2 lb. (1 kg), a process that takes three to four years. The result as with pata negra pigs is superior flavor. Chef Dani García, of the Michelin-starred restaurant Calima in Marbella, uses Veta la Palma's fish in one of his signature dishes. "It actually tastes better than most wild sea bass," he says.
The ecologically sound practices benefit more than the farm's fish and the people who eat them. By reflooding those drained lands, Veta la Palma transformed itself not just into a fish farm, but, somewhat unwittingly, into a refuge for migrating aquatic birds as well. Instead of the 50 bird species that inhabited the area when the farm started, there are now 250, many of them endangered: spoonbills, egrets and those spectacular pink flamingos.
Medialdea is a modest man, but as he watches the gawky birds poke through the water for food, he beams. "Because of our artificial intervention, the natural environment is improved," he says. "The point isn't to make use and conservation compatible. The point is to use in order to conserve."