The summer flounder, or "fluke", a flatfish noted for its fighting ability and flavor, is found in coastal waters from the southern Gulf of Maine to Florida. Important recreational and commercial fisheries for this species occur from Cape Cod to Cape Hatteras, North Carolina.
Like other species of flatfish, the fluke has both eyes on one side of its head and rests on the ocean floor on its side. The fluke is called a left-handed flatfish because its eyes are on the upper surface of the head when the fish is facing left. The species has a very large mouth that extends below and beyond it eyes.
Summer flounder are called the chameleons of the sea because of their ability to change color to match the bottom on which they are found. Generally they are white below and darker above, but they can turn various shades of gray, blue, green-orange, and almost black. The upper part of the fluke's body is marked with scattered spots that are darker than the general body color.
The angling record for summer flounder in Massachusetts is 21 pounds 8 ounces. Although the largest fluke may weigh up to 26 pounds, the average adult weighs 2 to 5 pounds and measures 17 to 25 inches long. A 15 to 16-inch fish, which is only 2 to 3 years old, weighs about 1 to 1 1/4 pounds. A 20-inch fish is about 3 to 3 ½ pounds, a 30-inch fish would be 10 pounds, and a 37-inch fish would be approximately 20 pounds. Females may live up to 20 years and weigh more than 20 pounds, while males rarely exceed 7 years of age and 3 to 5 pounds in weight.
Both males and females become sexually mature at the age of 3. The fecundity (number of eggs produced in a single spawning season) of females increases with size and weight. A 14-inch female produces about 460,000 and a 27-inch female about 4,200,000, eggs in a season.
Summer flounder inhabit inshore areas of Massachusetts during the warmer periods of the year. Fluke prefer eelgrass beds and wharf pilings because of the protection they offer. When threatened, they quickly bury all but their beady eyes in the sand or escape at surprisingly high speeds. In the summer, small and medium-sized adults are found on the sandy and muddy bottoms of bays, harbors, and along the open coastline. Most of the larger fish tend to stay in somewhat deeper water (50 to 60 feet). With the approach of fall, summer flounder migrate to more offshore waters in depths from 150 to more than 500 feet.
Reproduction takes place in the fall, as soon as the fish begin to migrate to wintering grounds, Peak spawning activity occurs from early September through early November in water temperatures of 53 to 66 degrees F and at depths of 60 to 160 feet. The center of spawning activity occurs off the coasts of New York and New Jersey, with less concentrated activity occurring in southern New England waters.
The eggs float in the water column, hatching 72 to 75 hours after being laid. After hatching, the larvae are carried into bays and estuaries where they will spend the early portion of their lives. Autumn water-circulation patterns in southern New England tend to distribute surviving larval fish southward along the coast, resulting in the virtual absence of young summer flounder in Massachusetts waters.
The summer flounder, which depends upon sight to capture its food, feeds most actively during daylight hours. Juveniles feed upon small shrimp and other crustaceans, while adults eat a variety of fish, including small winter flounder, menhaden, sand lance, red hake, silversides, bluefish, weakfish, and mummichogs, as well as invertebrates such as blue crabs, squid, sand shrimp, opossum shrimp, and mollusks. Adult are very active predators, often chasing schools of small fish to the surface and leaping out of the water in pursuit of them. This behavior clearly distinguishes the summer flounder from the other more sluggish species of inshore flatfish
Historically, the summer flounder has been among the most important commercial and recreational flatfishes on the East Coast. The commercial catch in Massachusetts has been modest compared to catches along the mid-Atlantic states, but the population summering in Massachusetts coastal waters faces an intensive offshore otter trawl fishery in the winter and spring. Commercial catches in the southern part of the fluke's range were stable from the 1950s to the early 1970s, while those in the northern portion of its range persistently declined over the same time period. In 1974 it was estimated that total commercial and recreational harvests exceeded a level that should be sustained for any extended period of time. Despite this caution, total harvest has exceeded the 1974 level in the 1980s.
Recreational fishing has always been a major component of the total fluke harvest, often exceeding commercial catches in the Mid-Atlantic States. The recreational catch ranged from 26 to 60% of the total harvest from 1979 to 1984 on a coast-wide basis. Certain regions have historically supported tremendous recreational fishing. One such region, the Great South Bay of Long Island, reported as many as 2,000,000 fluke landed yearly during the late 1950s and early 1960s. The total coastal recreational catch from 1979 to 1984 ranged from 5,000,000,000 to 18,900,000,000 fish.
Although populations' levels in the 1980s have been somewhat higher than they were in the 1960s and 1970s, persistently high harvest levels may once more reduce this species' abundance. The Atlantic States Marine Fisheries Commission developed a Summer Flounder Management Plan that was adopted by coastal states from Massachusetts to North Carolina in 1982. This plan established a minimum legal size limit of 14 inches to protect this important coastal fishery resource.
Fluke are well known for the aggressive way they grab bait and battle when hooked. They offer a particular challenge to the angler bold enough to use light tackle. Average-sized fluke, sometime called "Flatties," weigh about 2 to 4 pounds, while the aptly named "doormats" (so-called due to their similarity in size to a welcome mat) weigh 8 or more pounds and provide memorable battles for the angler lucky enough to hook them.
Summer flounder start to move inshore in July and provide action until the water begins cooling near the end of September. They can be found on sandy or muddy bottoms in many inshore habitats and are particularly abundant in fast-moving rips that gather debris and bait fish.
Anglers troll, chum, still-fish, and cast for fluke, but the most popular method is drifting the bait along the bottom. When drifting, the bail of the reel should be open and the line held by a finger. Once the line stops drifting and is tugged, it should run free for a moment to let the fish get the bait in it mouth before the hook is set. Casting a baited red and white bucktail rig from boat of shore can also be a rewarding approach. The jig should be retrieved with a slow, pumping action. When a fluke grabs that rig, the rod tip should be lowered to slacken the line; when the line tightens again, the hook can be set.
Shoreline anglers' use a medium-weight spinning gear spooled with 12-pound test line, while boat anglers fishing deeper water with strong currents need 15 to 20-pound test line on light to medium conventional gear to match the larger fish found there. Many anglers use commercial rigs with spinners. One favorite is a 3/8 to 1 ½ ounce weighted bucktail that can be baited with trips of fresh or frozen squid or baitfish, such as sand lance. If these baits aren't available, 4 to 5-inch strips of meat from the tails of fish such as sea robins can be used. Some anglers prefer strips of meat from the belly area of a fluke or bluefish, or half of a snapper bluefish.
A few anglers prefer homemade rigs made by tying a 1 to 2-ounce sinker to the end of a line and a "dropper loop" or three-way swivel 4 inches about the sinker. A 3-foot leader with a 1/0 to 3/0 hook is attached to the loop or swivel. A 4 to 5-inch strip of squid split along half its length is attached to the hook along with a baitfish hooked through the lips. This rig is bounced along the bottom as the angler drifts or casts.
The white, flaky meat of the summer flounder is highly rated due to its delicate flavor and texture. This versatile fish provides delightful dining when steamed, poached, baked, broiled, sautéed, fried, or microwaved. Large "door mats" can be quarter-filleted for most recipes or cut into steaks and grilled over charcoal or gas.
Commercial fishermen are required to submit a transaction report detailing their transactions with authorized dealers . If the fisherman is a federal permit holder and reported the transactions with dealers through the federal VTR program, then transactions do not need to be reported to the Division of Marine Fisheries, only a signed report indicating so. If the fisherman is not a federal permit holder, each transaction must be listed including the transaction date, the dealer the fish was sold to (including dealer name and permit number) and the pounds per transaction. Note that fishermen may only sell fluke to dealers authorized by the Division of Marine Fisheries to buy directly from fishermen. Fluke sold to un-authorized dealers is strictly prohibited. Furthermore, unreported transactions may be grounds for loss of the fluke endorsement on your license.
The fluke catch report is sent out with the renewal license application at the end of the year and is due as a requirement to renew the license for the next year. Even if you do not wish to renew your fluke endorsement, you must submit the report to renew the license. Furthermore, if you do not intend on renewing your license, the Division would appreciate it if you submit the report anyway.
Seafood dealers who wish to purchase fluke directly from fishermen must hold a valid Massachusetts seafood dealer permit as well as submit a primary buyer and quota managed species application to the Division of Marine Fisheries. Buying fluke directly from fishermen without prior authorization is strictly prohibited. Once a dealer becomes a primary buyer, there are reporting requirements that must be met.