First let’s go back in time to ancient Hawaii —more than 1,000 years ago — when Polynesian settlers raised fish and shellfish in stone ponds built next to the sea. They fed the fish and managed water quality with movable gates to allow the flow of the tides. So there’s nothing new-fangled about fish farming, but the science of aquaculture has come a long way.
Before my trip via speed boat across the Norwegian fjord to a floating platform overlooking salmon leaping energetically in their protected circular pens, I visited the National Institute of Nutrition and Seafood Research in Bergen.
Scientists here conduct research to provide advice on health and safety aspects of seafood wild and farmed, as well as the health of the environment. An important focus is nutrition — for developing feed composition for the fish and tailoring seafood products to optimize nutritional value for consumers who eat them. The connection between feed and fish quality is strong.
“We call it ‘fish in — fish out’” explained Harald Sveier, a specialist in aquaculture health for the Leroy Seafood Group. “The feed we use can impact the levels of omega-3 fats in the fish as well as other beneficial nutrients such as protein, vitamins and minerals.”
Fish oils are mixed into grain-based feed to provide the punch that boosts heart-healthy omega-3 content in farm-raised salmon (often much higher than wild salmon). But Sveier predicts a shortage of fish oils in the future with the global demand created by an increase in fish farming.
“That’s why we’re researching the use of plant-based omega-3 oils such as rapeseed oil,” Sveier said. “It’s still an excellent source.”
Room to jump and swim
A key ingredient in growing healthy fish is healthy water. Norwegian regulations require fish farmers to prevent overcrowding for the health of fish and fjord.
Unlike many fish farm operations in Asia, which Sveier described as “horrible,” it appears there’s plenty of room for Norwegian salmon to swim because the concentration of fish per confined area of water is kept at 2 ½ percent. Aquaculture technicians on the Leroy platform I visited monitored computer screens that keep track of the oxygenation of the water in each pen and showed an underwater camera view of the salmon swimming.
“If the fish are happy, they will grow faster,” Sveier said, “and because we’re using these practices today, the fish are healthier so we don’t have to use antibiotics.”
One sizable threat to farm- raised salmon is the tiny sea louse that attaches to the fishes’ skin and saps its strength. Norwegian fish farming operations, such as Leroy, are fighting back with a natural solution by introducing little fish that eat the sea lice and effectively clean off the salmon.
Fjord to fork
Salmon from Norway might not be labeled as such. Often you’ll see “Atlantic salmon” on restaurant menus or on supermarket signs indicating it could be from Norway, Canada or other north Atlantic nations.
But it could also be from Chile, where salmon farming is big business, too.
Chef Scott Gambone, food and beverage manager for the Ritz-Carlton Lodge at Reynolds Plantation, says, “Just as we tell guests the name of the farms where our fresh produce is grown, it would be good to be more specific about the waters the fish came from.”
Fish farmers in Norway, proud of their carefully tended crops, would like to see “ocean to table” join the “farm to table” movement, too.
Carolyn O’Neil is a registered dietitian and co-author of “The Dish on Eating Healthy and Being Fabulous!” E-mail her at carolyn @carolynoneil.com.