Saving Seafood

Researchers discover new fish virus that threatens global tilapia stocks

April 5, 2016 — An international team of researchers has identified a new virus that attacks wild and farmed tilipia, an important source of inexpensive protein for the world’s food supply. In work published this week in mBio, the online open-access journal of the American Society for Microbiology, the team clearly shows that the Tilapia Lake Virus (TiLV) was the culprit behind mass tilapia die-offs that occurred in Ecuador and Israel in recent years. The work also provides a foundation for developing a vaccine to protect fish from TiLV.

“Tilapia is one of the most important  industries worldwide,” says Eran Bacharach, a molecular virologist at Tel Aviv University in Israel and one of the lead researchers on the study. “Moreover, because they eat algae, they are ecological gatekeepers for freshwater and they are an inexpensive, important source of protein in poorer countries.”

The tilapia industry is valued at US $7.5 billion each year. Various countries in Asia and South America are the largest tilapia producers and the United States is the largest importer, consuming 225,000 tons of these fish each year.

Read the full story at Phys.org

A Massive Aquaponic Lettuce And Fish Farm Will Grow In A Brooklyn Warehouse

March 31, 2016 — BROOKLYN, N.Y. — “We build industrial-scale ecosystems.” So says Jason Green, CEO and co-founder of Edenworks, a Brooklyn-based urban farming startup. Unlike a typical indoor farm—a sterile environment, sometimes run by people in gloves or even by robots—Edenworks tries to build in as much life as possible.

In their new warehouse, set to open in New York City this summer, fish will grow in tanks, bacteria will turn the fish waste into a rich fertilizer, and plants will use that fertilizer to grow. “That’s the way the Earth works—we’ve just turned it into kind of like a manufacturing process, but it’s all based on ecology,” he says.

In a year, the 6,000-square-foot space will produce around 180,000 pounds of salad greens and tilapia for local grocery stores and restaurants.

The startup is one of a handful that will open large-scale urban farms this year. Nearby, in Newark, New Jersey, Aerofarms is turning a vacant steel factory into a 69,000-square-foot “aeroponic” farm. Gotham Greens just opened the world’s largest rooftop greenhouse in Chicago, an addition to the others it runs in New York. FarmedHere, which also runs a large indoor farm in Chicago, plans to open a nationwide network.

Edenworks claims to have an advantage over most of its competitors: because it uses aquaponics—combining raising fish with plants—it says the salad greens it grows actually taste better. (FarmedHere also uses aquaponics; most others use hydroponics or aeroponics to pump in a mix of nutrients separately, without using fish)

Read the full story at Fast Company

Shift to plant-based fish feed could hurt health, environment

March 25, 2016 — In an effort to make fish farming more sustainable, the aquaculture industry has been cutting back on feed made of other fish and replacing it with plant-based alternatives. But a new study warns that may make the fish less healthy to eat and have negative impacts on the environment.

Many fish species that are farmed, including Atlantic salmon, the most farmed fish in Canada, are carnivores that eat feed traditionally based on fish meal and fish oil. Environmental advocates such as Greenpeace have criticized the practice as unsustainable, as wild fish that could be used to feed people or maintain wild populations need to be caught in order to produce the fish food.

“They realized that we’re grinding up a lot of fish to feed the fish,” said Jillian Fry, director of the Public Health and Sustainable Aquaculture Project at Johns Hopkins University in Baltimore, Md.

The price of fish meal and fish oil has also increased with demand.

Omega-3 concerns

The study said the use of plant-based ingredients could reduce the amount of healthy omega-3 fatty acids in fish – one of the things that makes fish like salmon attractive and tasty to consumers.

While this is something salmon farmers are aware of and trying to avoid, Fry says, omnivorous fish that already eat more plant material and have less omega-3s, such as tilapia, may end up with even lower levels.

“Anywhere it’s decreasing in our diet, we need to pay attention.”

Read the full story at CBC News

Scientists Say Feeding Fish Soy, Not Fish, More Sustainable

Editor’s Note: One key aquaculture issue not addressed by the article is the importance of marine ingredients in ensuring that farmed seafood diets contain enough omega-3 fatty acids and other nutrients. Marine ingredients like fish meal and fish oil are currently the best way of transferring these nutrients to farmed fish and on to consumers. To learn more about aquaculture and marine ingredients, view this video.

November 22, 2015 — SIOUX FALLS, S.D. — Research supported by the soybean industry is looking to convert some farm-raised fish into vegetarians.

A South Dakota State University fisheries scientist is developing a soy protein feed that’s tasty and easily digestible to eventually reduce the industry’s need for using wild-caught fish as food for farm-raised fish.

Much of the tilapia, Atlantic salmon and catfish that Americans toss into their shopping carts are raised in fish farms, where companies traditionally feed them pellets containing anchovy, menhaden and herring. The harvest of those small species has pretty much flat-lined, SDSU professor Mike Brown said, and humans’ increased demand for fish has driven up the cost of creating the pellet feed.

“We’ve fully exploited that resource,” he said, noting that the goal is to create a more sustainable – and cheaper – food source. Traditional fish feed is currently costing between $1,450 and $2,000 per ton, while soybean meal runs about $425 per ton, Brown said.

But some environmentalists worry that feeding fish species an uncommon food source could produce excess waste that muddies up inland tanks or offshore waters where fish are raised.

Read the full story at the New York Times