There’s nothing fishy about the seafood at limited-service restaurants today. Operators are focused on meeting consumers’ demands for seafood that is creative, healthful, and sustainable, from grilled fish fillets to upscale lobster rolls.

“There’s a little oversaturation in chicken, burgers, and pizza,” says Andrew Gruel, founder of Slapfish, a seven-unit southern California seafood chain. “People are eating more seafood now that they realize how healthy and accessible it is.”

According to Chicago-based market research firm Technomic Inc., 64 percent of the nation’s quick-service and fast-casual restaurants offer a seafood item, whether it’s fish tacos, shrimp fried rice, or anchovies on pizza. The number of seafood items on regular limited-service menus is virtually unchanged from a year ago, with 54 percent featured at quick serves and 46 percent at fast casuals.

The most offered seafood, according to Technomic’s MenuMonitor database, is shrimp. It’s in a variety of dishes, part of many ethnic menus, and a popular add-on protein at restaurants as diverse as Noodles & Co. and Pei Wei Asian Diner.

Even Atlanta-based wings chain Wing Zone serves a shrimp dish. “Almost all of our food items are fried, so having fried shrimp is easy on the operation,” says Dan Corrigan, director of marketing. “We actually changed our shrimp recently to more of a jumbo breaded shrimp, and that’s doing well.” The shrimp is served with a dipping sauce. It’s only 3 percent of the sales, Corrigan adds, but when Wing Zone tested removing the item from one restaurant, guests wanted it back.

One reason fast casuals make up a big percentage of limited-service eateries serving seafood is its premium price, says Technomic executive vice president Darren Tristano.

“That’s harder to translate to quick service,” he says. “Seafood’s price points are more full service or fast casual.” Nonetheless, many big limited-service restaurant operators offer at least one seafood menu item, such as the Filet-O-Fish at McDonald’s or Tuna Sandwich at Subway.

Keeping seafood sustainable is more important to Americans today than ever before.

“Customers are increasingly asking where their food comes from, how is it produced, is it safe, and are there any environmental issues when it’s produced,” says James Baros, aquaculture and sustainability coordinator at provider National Fish and Seafood of Glouchester, Massachusetts. He points to Atlantic cod and some tuna species as examples of how industrial fishing nearly obliterated stocks. “It was an important lesson to learn,” he says.

Half of U.S. seafood is caught wild, while the other half is farmed. That’s up from 15 percent farmed three decades ago. “We’re seeing a big transition to aquaculture,” Baros says. “Fish is the last major food we go out and catch. You don’t hear of catching cows in the wild.”

Salmon, shrimp, and tilapia are the most popular farm-raised seafood varieties for Americans. But wild caught still has a certain cachet for diners, and many restaurants point out that their fish is wild caught. That includes the largest quick-service seafood operator, Long John Silver’s, where the classic battered and fried Fish and Chips remains the biggest seller.

“Our two main types of fish are Alaskan pollock and cod. Both are wild caught and sustainable,” says chief executive James O’Reilly. “It takes a lot of commitment to maintain a sustainable supply.”

The fried fish is usually pollock, while cod is available either fried or baked. Shrimp, mostly farm-raised in South America, can be baked or fried, and Long John Silver’s also sells fried crab cakes and clams, with langoustine bites offered as a seasonal item.

“Our seafood menu has evolved,” O’Reilly says, adding that the brand has increased its healthier options while also adding more portable items, including fish tacos, seafood-salad sandwiches, and fish strips. These steps are helping the Louisville, Kentucky–based company maintain its seafood leadership, O’Reilly says. “I believe that growth will be fueled by the addition of Millennials concerned with quality and sustainability,” he says.

Battered fried fish is also the No. 1 item at Captain D’s, which has positioned itself as a fast-casual seafood dining experience. While about two-thirds of the menu is fried, the biggest growth is in grilled items, says Jason Henderson, vice president of product innovation for the Nashville, Tennessee–based chain. Double-digit growth pushed grilled food to about 10 percent of sales in 2014.

The grilled menu includes Alaska salmon and pollock, tilapia, and shrimp, while the fried fish is pollock. The chain also features breaded flounder and catfish, a nod to its Southern roots, as well as fried shrimp and stuffed crab shells.

Most diners don’t ask about the food’s source, Henderson says, but the menu often makes it quite clear, particularly with Alaskan fish.

“We’ve worked with a long list of accounts to increase the visibility of Alaska seafood,” says Claudia Hogue, foodservice director at the Alaska Seafood Marketing Institute. The state produces 53 percent of America’s seafood harvest.

In addition to white fish—cod, halibut, and pollock—Alaska is known for its wild salmon. Some salmon varieties are available year-round, but for most, the season kicked off in May and runs through the summer. There are also Alaska Dungeness and other crab varieties, along with scallops and prawns.

“We encourage people to use the Alaska name because we know customers more and more want to know the origin of their fish,” Hogue says. Studies commissioned by the institute indicate consumers feel better about buying Alaska-brand seafood.

Southern California–based Sharky’s Woodfired Mexican Grill makes a point that fish served in its tacos, burritos, bowls, and other items are wild caught, and varieties like salmon and cod are from Alaska.

“We’re a lifestyle brand, and many who visit us recognize the benefits of wild-caught seafood,” says David Goldstein, chief operating officer of the two-dozen-unit chain.

The most popular seafood item is Charbroiled Fish Tacos featuring salmon or wahoo. Fish tacos are $4.29, versus $2.99 for chicken and $3.99 for steak. Other favorites are the Salmon Power Plate, Salmon Burrito, and Tempura Cod Tacos.

Sharky’s also features mahi mahi, pollock, and shrimp, and all these offerings provide “a real point of differentiation for us,” Goldstein says. Seafood has grown to 11 percent of sales, twice what it was a few years ago.

At Ivar’s Seafood Bars in and around Seattle, fish (Alaska cod) and chips is the big draw. “We ride the up-and-down tides on price points,” says Carl Taylor, director of operations at the regional favorite. “It’s a premium product we serve.”

The majority of the menu is fried. In addition to cod, there’s fried halibut, salmon, clams, scallops, big and small prawns, and oysters. The menu also has several chowders, grilled halibut and salmon, Dungeness crab, and salads with different seafood varieties.

“Within the past three years, we expanded the grilled items and added fresh fish,” Taylor says. “We sell it as long as the run is going.” The two-piece Fresh Halibut Platter, with cole slaw, wild rice, and cornbread, sells for $15.99.

Ivar’s oysters are from the Washington and Oregon coasts. The Alaska Dungeness ($9.29) is higher in terms of price, he says, but worth every penny. “I could go out and get rock crab and mix it with the Dungeness to lower the price, but we don’t.”

Just as consumers equate wild salmon with Alaska, they link lobsters with Maine. That’s the draw at New York–based Luke’s Lobster, which has 17 fast-casual “shacks” in Mid-Atlantic coast cities and recently expanded to Chicago.

“We are exporting the experience of the Maine lobster shack,” says founder and president Luke Holden, whose father has been in the seafood industry for years and built up well-established relationships with fishermen across the Northeast coast.

The $15 fresh lobster rolls are made to order in the traditional Maine style, with a quarter pound of chilled lobster meat in a top-split bun—the sides are shaved to toast better—plus a slick of mayonnaise, Holden’s secret seasoning, and lemon butter.

“All the meat is from the claws and the knuckles; the knuckle tends to be the most delicious part,” Holden says, adding that the tail is considered premium, but not for lobster rolls. “You would have a tug of war with a warm bun and a chewy tail.”

The shacks also offer crab and shrimp rolls, Jonah crab claws, and New England clam chowder. Crab is purchased from fishermen from Maine to Rhode Island, while the shrimp is wild from Canada.

Lobsters were sustainably caught long before it became a trend, says Matt Jacobson, executive director of the Maine Lobster Marketing Collaborative. Some rules governing trapping date from the 1870s. Today, lobsters must be males between 3.5 and 5 inches in body length. Others are tossed back—smaller ones to grow, and females and bigger males to breed.

While many consumers consider lobsters a center-of-plate item served whole, there are many other uses for the meat, Jacobson says, including in salads, pasta, and Asian dishes. Lobster rolls are also growing in popularity nationwide.

Lobster rolls and fish tacos are the two top sellers at Slapfish. “Lobster is incredibly indulgent, and the growth in our lobster rolls has been 100 percent due to Instagram and social media,” Gruel says. “People see them online and want them.”

The fish tacos are available with grilled or fried fish, largely wild-caught species ranging from Pacific cod to Maine’s Acadian redfish, depending on the season. The tacos include cabbage, avocado purée, and pickled onions.

“The key is the balance,” he says. “You want a good amount of cabbage to provide that great crunch, and the acidity to cut through the richness of the fish.”

Slapfish’s limited entrée menu also includes the Crabster Grilled Cheese sandwich with lobster and crab, and a Surf ‘n Turf Lobster Burger smothered in lobster and caramelized onions. There’s also fish and chips, chowder, chowder on fries, and shrimp.

A taste of the Hawaiian Islands is part of the draw at Coconut’s Fish Café. The four-unit chain began in Maui, Hawaii, and has since moved to the mainland. It features mahi mahi, ono—the Hawaiian name for wahoo—and ahi.

“They are all wild, and they are line caught,” says Dan Oney, chief operating officer. “The people we buy from are able to track the fish to the boat. It’s the concept of taking care of the earth and taking care of our customers.”

Most of the fish is grilled, and the ahi tuna is seared rare and served with wasabi. “We have big, beautiful, 6-ounce fillets of fish that if you go to a sit-down restaurant, you would pay $30 or $40,” Oney says. Coconut’s platters start at $10.99.

Mahi mahi and ono are in the seafood pasta, as well as the fish tacos that include family-recipe coleslaw and tomato and mango salsas. There’s also a fish sandwich and other fried items—fish and chips, shrimp, calamari, and coconut shrimp—on the menu.