Freshwater Institute's Fresh Ideas About Sustainable Seafood

Local food is all the rage these days. People love to buy local. If you put up a sign over a bin of produce, eggs or dairy products, saying they are locally grown, and the price isn’t too bad, that bin will sell out fast. Local meat is popular too, as is seafood, provided you live near the ocean.

But what if you live in the mountains, hundreds of miles from the ocean, and not necessarily on a high speed-truck route? Is it possible that you could purchase high-quality, local seafood there, too?

Folks at the Conservation Fund’s Freshwater Institute, nestled in the mountains of West Virginia, say you can. They should know -- they’ve been raising delicious and nutritious trout and salmon there for over 20 years. And they’ve been doing it in a manner that’s about as sustainable as you can get, other than catching it in the wild, something that’s become increasingly rare and expensive. I took a drive down to see what they were up to.

Aquaculture in the U.S.

The seafood industry, here in the U.S., as we’ve noted before, is in a rather strange state. Though we manage some of the highest quality wild fisheries in the world, we export nearly 70 percent of all the fish we catch and import 93 percent of what we eat.

Says Joe Hankins, the Freshwater Institute’s director: “The seafood counter historically is the only place in the grocery store where we have been hunting and gathering, and that is rapidly changing to a farmed environment. And with the interest in local and domestic production, sustainability, and carbon footprint, the emphasis is now on producing more seafood here in the U.S.”

As interest in nutrition has grown, salmon and trout have swum to the forefront because of their very high levels of Omega-3 oils.

Since wild stocks will need a long time to replenish, and pressure is on to keep hauling them in, not to mention growing concerns over mercury and other toxins, it seems likely that if the supply is going to grow, it is going to have to be farmed, as two-thirds of our seafood already is. But what method is best?

Today, there are three primary types of fish aquaculture.

There are ponds, which are primarily located in the South, where warm-water fish like catfish and tilapia are raised. This has traditionally been the largest source of farmed fish in the U.S. But recently the supply has shrunk by half, due to a combination of competition from overseas and the rising cost of commodities like corn used in fish feed. When feed prices shoot up, fish farmers may just choose to drain their ponds and use that land to grow feed instead. While waste and disease are contained within the ponds, these must be managed. The ponds also take up a large amount of land.

The second method, is the use of flow-through raceways. These are primarily situated in the Snake River Valley, in Idaho, where 75 percent of the trout are produced. Spring fed, the water flows into the river. Production is limited by the daily amount of pollution that can enter the river. Fish farms have water rights which have become increasingly valuable, especially in times of drought.

Salmon is generally raised using net pens along the coastline. Some are released when they smolt, since they will return by nature. Issues include pollution, disease transmission in both directions, and fish escapes which can lead to undesirable interbreeding. Offspring of domesticated fish are less likely to survive in the wild.

The Freshwater Institute solution

The land-based production technology developed at the Freshwater Institute is really something altogether different. The fish are raised indoors in giant tanks. Electronically-controlled pumps and filters maintain healthful conditions. Waste is removed and provided to local farmers for fertilizer.

As a result, the process avoids just about all of the problems described above. It doesn’t allow escapes, captures the waste, internalizes the waste treatment cost, and prevents disease from entering or leaving the farm. Freshwater Institute researchers used certified, pathogen-free eggs, for 15 years with no antibiotics, pesticides or vaccines, and no GMO salmon. All of these things lower their production costs. And it yields anywhere from 100 to 200 times more fish per acre than the ponds do.

Says Steven Summerfelt, the Institute’s director of aquaculture systems research: “Water treatment is why this works. It’s really just a huge aquarium.”

It sounds almost too simple, but it’s far from it. The team has spent 20 years testing, calculating and testing some more — figuring out the best flow rates, filtration methods, water temperatures, fish varieties, feed compositions and so on, largely with USDA funding. Many publications later, this nonprofit operation is spinning off satellites that raise and sell fish.

The beauty of it is, they can put it anywhere, which brings us back to the way the market loves local product. Says Summerfelt, “We can put it outside the metro areas on the East Coast; we can put it outside of Vegas or LA, and in fact, people have been doing that.”

But don’t salmon spend part of their lives in the ocean? Yes, they do.

“Salmon grow really slowly the first year, until the first winter when they smoltify. Then when they are ready to osmoregulate (maintain salt and water balance in the ocean) they grow really fast. We can do the same thing in fresh water. We trick them with lights so that they switch into the fast growth mode. Once they hit one pound, they start to grow a pound a month, until they’re nine or 10 pounds.” Summerfelt says.

Salmon are highly efficient at converting feed to food at a ratio of about 1.1 to 1. Compare that with beef, which is somewhere around 8 to 1. According to Summerfelt, salmon are the most efficient animals on the planet to raise for food.

The water footprint of the system is modest and improving. Currently, 99.5 percent of the water is recycled; new innovations are expected to improve that to 99.95 percent.

The biggest overall footprint is growing the feed, which continues to be a subject of study. But there are even brighter spots on the horizon. North Country Clear Water in Wisconsin has a project in development, designed by Freshwater Institute, which will raise Atlantic salmon and rainbow trout and then feed the effluent into a decoupled aqua-/hydroponic operation. The runoff will fertilize organic lettuce and other fresh leafy greens. The water can then be returned to the fish operation, making the overall system zero discharge. In a symbiotic relationship like this, the feed to food ratio completely flips. Instead of getting almost a ton of fish for a ton of feed, now, as much as 10 tons of food can produced from a single ton of feed.

Images by RP Siegel