Sustainable Aquaculture: Net Profits


Sustainable Aquaculture: Net Profits

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 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.

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. of fish to every 35
cu. ft. of water — helps
keep the fish free of parasites
. 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 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.
. But at Veta la Palma,
they wait until each fish
weighs 2 lb. , 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.”

See pictures of a wildlife forensics lab.

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