...consumers are becoming more aware of the environmental effect of their dining habits, and are consciously avoiding ordering certain types of seafood. Certain species of fish, such as farm-raised catfish and tilapia, are believed to alleviate pressure on wild saltwater and freshwater stocks, and can be well-received on menus when well prepared.

Unfortunately, a significant amount of discarded bycatch of other species is still caught along with shrimp.) The region where the fish was caught affects the viability of the local fish population. For example, commercial fishermen primarily use longlines and hook-and-line gear to catch mahi mahi or "dolphinfish." The hook-and-line method, which is used in the southern United States as a result of strong fisheries management, results in little to no bycatch.

Many commercially popular species have been fished to near extinction in parts of the world. These include orange roughy, "Chilean seabass" (Patagonian toothfish) and Alaska king crab, which you would often find on the menus of many fine restaurants. As noted, consumers are becoming more aware of the environmental effect of their dining habits, and are consciously avoiding ordering certain types of seafood. Certain species of fish, such as farm-raised catfish and tilapia, are believed to alleviate pressure on wild saltwater and freshwater stocks, and can be well-received on menus when well prepared.

Here, chefs Michael Tsonton and Dan Butler, longtime culinary contributors to this magazine, share their thoughts on these sustainable species - positive and negative - and recipes to take advantage of their gastronomic qualities.

Michael Tsonton: 'Don't Get Tied to Southern Presentations When Thinking Catfish'

Both tilapia and catfish can be "good" and "bad" as far as sustainable goes. Tilapia, in particular, is listed on "don't buy" lists of certain environmental watch groups, depending on how they are raised. My understanding is that Asian tilapia is raised in net pens, allowing the waste to run off in the ocean. (Tilapia fish have a high tolerance to the nitrogenous and ammonium waste products they excrete. This means a relatively great number of fish can be raised in relatively small holding ponds; however, the water in which they are raised can adversely affect the environment if not carefully disposed. It can also taint the flesh of the fish if holding pond water is not properly managed.)

The best holding systems for the environment are "closed," meaning that the water is not connected to open streams, rivers or the ocean. "Open" systems just recycle the waste back into the surrounding water. U.S .and South American farms are generally run more cleanly. These issues also arise with catfish. The following are two sites we use to make sure we "do the right thing" to the seafood we place on our menus. They are www.seafoodwatch.org and www.seafoodchoices.com. Fresh fish is a funny thing. Not funny like ha-ha either, but funny because buying fish these days has some rules. What to buy, when to buy, and how much can even be fished for you to buy. Not funny. As the world's population continues to grow, demand for seafood is following suit. Health benefits and increased information about seafood keeps the world's fishing vessels in a constant battle between deeper waters and conservationists.

The rise of seafood farming has become a necessary addition to wild seafood fishing. Farmed seafood, like wild-caught, has both a positive buying list and a not-so-positive list. Buying farm-raised seafood requires some degree of knowledge from you, the shopper. Two farmed fish that find themselves on both the buy and don't buy lists are tilapia and catfish. Both of these fish are plentiful, lean, easy to prepare and easy on the wallet. Tilapia has found wide appeal in the Far East as well as here in the United States, where it has become a top 10 consumed fish by volume in the states. Seafood experts estimate that by 2020 tilapia will climb to number three on the consumption chart.

The United States imports more than 140,000 pounds of tilapia, just a fraction of the 3 billion pounds raised each year in more than 50 countries. Buying U.S.-raised tilapia helps ensure that you buy fish raised without eco problems, like water pollution. When buying tilapia, ask for U.S.-farmed fish. Fillets are graded by size, 3-5 ounces, 5-7 ounces and the most popular, 7-9 ounces. Tilapia takes on the flavor of the water in which it is raised, so the best-quality fish has a very clean taste. Stay away from Asian-produced fish. Most Asian farmers treat frozen fillets with carbon monoxide to give the fish a pinkish color. Many of these fish are passed off as snapper in cheaper sushi restaurants and should not be eaten raw. Tilapia loves the saut‚ pan most. Seasoned with just sea salt and fresh ground white pepper or a more flavorful rub of aromatics, tilapia is wonderful when quick-cooked and lightly sauced or finished with fresh herb vinaigrette. The same domestic buying sense applied to tilapia also pertains to the purchase of catfish.

With hundreds of catfish species worldwide farmed, none is more beloved by Americans than the channel catfish. Farmed mostly in the Delta region of the Mississippi, channel catfish is one of the major players in the U.S. aquaculture industry today, and is praised by conservation groups. U.S.-raised catfish is popular throughout the states for its sweet meat, easy-to-prepare status and affordability. Once a regional fish, catfish has found its way onto menus from San Francisco to Maine, in concepts from French to Asian. U.S. production of catfish is 630 million pounds, making it the fifth-leading consumed fish in the states. When buying catfish look for U.S.-raised fish only.

Again, like tilapia, stay away from catfish farmed in Asia. Look for clean-smelling white flesh and stay away from fish that have any browning or are beginning to look gray. Catfish producers test their fish before production for algae, ensuring fillets don't taste or smell muddy. Catfish makes a great substitute for other freshwater fish like perch or whitefish, and are wonderful grilled, saut‚ed and, of course, fried. Don't get tied to Southern presentations when thinking catfish. Try garlic and black bean sauce from China or a simple caper-butter sauce made in the pan with some lemon and white wine.

Dan Butler: 'If Catfish's Appeal Can be Described as Mainstream, Tilapia Fills the Upscale Niche'

For the environmentally conscious fish eater, the decision of what's for dinner comes long before dinnertime. Many factors go into making environmentally responsible seafood choices. Harvesting methods should not damage the seafloor or produce unintentional bycatch. And, above all, bringing the fish to market should not be an act that ultimately endangers the existence of the species. It should be, in a word, sustainable. Two of the fish that most aptly fill this bill are tilapia and catfish. Both are available almost exclusively farm-raised and are well-managed so as to have as little environmental effect as possible.

The fish are raised in ponds that keep them isolated from the wild population. They're fed high-protein pellets until they reach harvesting or market size. The result with these two species, unlike some others, is that they yield more protein in edible product than they consume. This is one of the most environmentally sound and sustainable methods of providing fish to the market. The factors that make these choices desirable from a social and ecological standpoint also present challenges at the dinner table. That said, in the hands of the unindoctrinated cook, the results can be ... well ... bland. The results of feeding these fish pellets just can't compare to the taste their flesh naturally develops from their diet in the wild. Why not serve more flavorful pellets? That's not my department. I'm just the chef. The blandness of the fish can actually work to the advantage of the adventurous cook.

Catfish and tilapia marketing campaigns might call the fish a blank canvas waiting for an artist's bold touch. Chefs might call them a problem that needs a creative hand to resolve. While neither has an assertive taste, catfish has the firmer texture and will hold up better to more rigorous handling like frying or stewing (within reason of course; it is, after all, still a tender fish). Even though catfish is a very versatile fish, recipes for it are often geared toward southern cuisine, either because of tradition (fried catfish and hushpuppies, anyone?) or because 95 percent of all the farmed catfish raised in the United States comes from four southern states: Alabama, Mississippi, Arkansas and Louisiana.

If catfish's appeal can be described as traditional and mainstream, tilapia fills the upscale contemporary niche. It is served in white tablecloth restaurants everywhere, including mine. The flaky but firm texture and ever so slightly sweet flesh make it a versatile fish for modern interpretations. For restaurants, it's a great choice because it cooks very quickly (making it easy to "pick up" in a hurry) and has the bonus of being downright inexpensive compared with crowd-pleasers like grouper, halibut or turbot (a fact that's bound to entice a chef to find a place for it on his menu). With a deft hand in the kitchen there's no need to sacrifice a clean plate for a clear conscience. You can find some concise information about fishing methods, and sustainability is available on the Seafood Watch pages of the Monterrey Bay Aquarium Web site, www.mbayaq.org/cr/seafoodwatch.asp.

Dan Butler's Pistachio-Crusted Tilapia With Pineapple/Curry Cream (Serves 4-6)

Main ingredients - 4-6 oz. farm-raised tilapia fillets - Salt and white pepper - 2 egg whites - 1/2 cup chopped pistachios - 2 tablespoons vegetable oil Season the tilapia with salt and pepper. Beat the egg whites for a few seconds with a fork until smooth. Pour into a shallow bowl or dinner plate. Dip one side of the fillets in the white and then pass them into the nuts. Press down to make sure that the nuts adhere well to the fish (the egg white is there for that reason).

With a medium heat setting, heat the oil in a skillet large enough to accommodate the fish. Place the fish in the skillet, nut side first. Flip after a minute or two, when the pistachios have lightly browned. Finish cooking for a couple more minutes (until the flesh flakes pure white) in a 350-degree-Fahrenheit oven. Pineapple/Curry Cream Ingredients - 2 tsp fresh grated ginger - 1 tsp minced fresh garlic - 2 tsp chopped shallots - 1 stalk lemongrass chopped - 1 tablespoon vegetable oil - 1 tsp red curry paste - 1 sprig basil - 2 sprig mint - 2 sprig cilantro - 10 oz. pineapple juice - 14 oz. coconut milk In a saucepot, heat the oil and add the ginger, garlic, shallots and lemongrass and let saut‚ for a few minutes without taking on color.

Add the curry paste and incorporate well. Then add the herbs and mash them well into the mixture. Add the pineapple juice and bring to a soft boil, and let the liquid reduce (evaporate) by about half its volume. Add the coconut milk and again, allow it to reduce by half. Strain through a fine sieve and adjust the seasoning. Ladle 4 ounces of the sauce into a shallow bowl and place the tilapia fillets on top. Serve with basmati rice for an aromatic Asian dish.

Michael Tsonton's Grilled U.S.-farmed Catfish With Summer Peach and Jalapeno Salsa (Serves 6-8)

Ingredients: - 12-16 dressed catfish fillets about 4 oz. each, kosher salt and fresh cracked black pepper, canola oil for brushing fish, and grill - 6 large ripe peaches cut in half and pits removed - 2 large jalapeno peppers cut in half - 1 sweet onion peeled and cut in half - 1 red bell pepper - 1 bunch fresh cilantro stemmed and rough-chopped - 1 bunch fresh flat leaf parsley stemmed and rough-chopped - 3 oz. extra virgin olive oil - 3 oz. sherry vinegar Prepare a very hot grill by brushing the grates well with a wire brush. Lay out the cut peaches, jalapenos, onions and the red pepper.

Brush the grill with some of the canola oil. Lay the peaches and the vegetables on the hot grill cut side down. Place the whole red pepper on the grill, also. Allow the peaches and the cut vegetables to become well-colored without turning. Turn the red pepper as each side becomes charred and black. Remove the peaches to a plate, season with kosher salt and some cracked black pepper, and allow them to cool. Remove the onions and peppers to a bowl, season with the salt and pepper and cover with plastic wrap. When the red pepper is charred all over, place it in a small bowl and cover with plastic.

After the red pepper has steamed and is cool, peel the skin from the pepper. Reserve all the juices from the resting peaches and vegetables. Cut the peaches into medium dice. Cut the onions and jalape?os into small dice. Remove the seeds and the ribs of the red pepper and cut into small dice. In a bowl large enough to hold the peaches and vegetables, mix together the reserve juices, and the sherry vinegar. Whisk the olive oil in the mixture. Fold the peaches and vegetables in the dressing and toss with the chopped cilantro and parsley. Adjust the seasoning.

Scrape the grill again with the wire brush. Season the catfish fillets with the salt and cracked black pepper. Lightly brush the fillets with the canola oil and grill the fish on each side for 2-3 minutes, depending on thickness. Serve the catfish on a bed of crisp romaine lettuce with a simple boiled potato dressed with olive oil and lemon juice and pass the salsa. This dish would go nicely with a Riesling from Washington state or crisp Chablis from France.

Dan Bulter's Pan-Roasted Catfish Fillets (Serves 4-6)

Ingredients: - 1/4 cup flour (all-purpose) - Pinch of chili powder - 4 farm-raised catfish fillets - Salt and pepper - 4 tablespoons vegetable oil - 2 teaspoons finely chopped garlic - 1/4 cup white wine - 1/4 cup clam juice - 1 chopped green bell pepper - 1 chopped red bell pepper - 1/2 cup cooked black beans - 1 chopped tomato - 1 tablespoon oil - 1 chopped scallion - 2 tablespoons sour cream Blend the chili powder and the flour together and place in a shallow vessel (like a plate).

Season the fillets with salt and pepper and dredge them in the seasoned flour. Heat the oil in a large saut‚ pan over medium heat. Place the fillets in the oil and pan fry until browned on one side (1-2 minutes). Flip the fillets and add garlic, then the peppers, and then the white wine and clam juice. Cover and continue cooking a few minutes until the fish is flaky white and breaks with a fork touch. Carefully extract the fish and place on a serving platter. In the pan add the tomato, the black beans and then the chopped scallion. Bring to a boil (or heat through) and pour over the catfish fillets. Finish with a dollop of sour cream. Serve with jasmine rice.