Are Sardines as Sustainable as They Seem?

The go-to recommendation for sourcing sustainable seafood is to eat fish that are low on the food chain. It's a tip that ­typically sends us straight to sardines, and for good reasons: they're affordable, delicious and full of calcium, vitamin B12, omega-3 fats and protein. But are they truly sustainable? Here the advice gets murky.

For the second year in a row, U.S. Pacific sardines cannot be fished. The fishery is closed due to a dangerously low dip in population. The estimated weight of the fishable stocks (aka the population) went from more than 1 million metric tons in 2006 to just 106,000 metric tons in 2016. Scientists say the decline is part of a naturally occurring "boom and bust" cycle, mainly influenced by environmental factors, including changes in ocean temperatures.

A drop in the sardine population affects other species. For instance, in the last three years, California sea lions have starved to death in record numbers.

What about fishing? "Fishing can contribute, but the decline is primarily environmentally driven," says Kevin Hill, Ph.D., supervisory research fishery biologist at the National Oceanic and ­Atmospheric Administration (NOAA). "You don't want to hit the population too hard when it's going through a decline." But he says we were nowhere near the scale of fishing that led to a sardine-fishing moratorium between 1967 and 1986-in the 1950s and early '60s, over 50 percent of the population was fished out of the ocean annually. Leading up to the recent decline, fishing rates were around 10 to 15 percent, peaking at 30 percent.

In keeping the fishery closed, NOAA is protecting against overfishing. Recent preliminary data suggest sardines may be on the rise, but more concrete surveys are needed before we can fish easy.

Human consumption of sardines in the U.S. makes up only a small part of the fishing pressure. Globally, 90 percent of harvested forage fish (which includes sardines) are used for bait, pet food or farm-­animal feed. But this isn't an efficient or sustainable use of sardines. For instance, it takes 20 pounds of sardines to produce just 1 pound of farmed bluefin tuna.

Environmentalist Geoff Shester, Ph.D., of Oceana, an international ocean- protection organization, says it would be better not to use sardines as animal feed and to just eat them ourselves. "If we're eating them, we're creating demand for a product that doesn't have to be caught in such large quantities to get the same amount of protein," he says. "It provides more money for the fishermen and feeds more people. Right now, inefficiency is driving the harvest.

"The value these fish have is often simply underestimated," Shester continues. "They really drive the health of our ocean and of our seafood supply. It's something we're just learning."

When you're buying sardines, look for brands with the Marine Stewardship Council (MSC) logo. Or look for Pacific sardines, which net a "green" rating from the Monterey Bay Aquarium's Seafood Watch. You can still find pre-closure canned Pacific sardines. Skip sardines that come from the Mediterranean, a region that gets a red "avoid" rating.

Try It Yourself

Here are three great ways to try sardines from sustainable-seafood chef Barton Seaver:

• Toss 1 can each olive-oil-packed sardines and rinsed chickpeas with a splash of olive oil, a little red-wine vinegar, chopped fresh mint, orange zest and a big pinch of mace.

• Smear a little room-temperature butter on toasted sourdough, top with a couple sardines and a sprinkle of crushed red pepper. The butter mellows the rich flavor of the fish and the slight tang of the sourdough and bite of the chiles harmonize the dish.

• Sardines were originally preserved between layers of sea salt in barrels. As they cured, and their juices ran out and the pickled in their own briny liquid. Now preserved in cans, salt-packed sardines are commonly used in Southern Italian cuisine and are available in gourmet markets and from online specialty food retailers. Before using, the sardines need to be soaked in water to remove the extra salt before eating. Wipe as much salt as possible off of each flattened fish and soak in bowl of cold water 12 hours in the refrigerator, changing out the water once or twice. Pat dry and cut the meat off of both sides, then gently peel the meat off of the bone structure. Try marinating the fillets in garlic-thyme flavored vinegar and wrapping them around olives or chiles, or tossed with cherry tomatoes.