Longline Fishing

 

Iced yellowfin tuna from a longliner in Barnegat Light, NJ (N.Stolpe photo)

  

This article is part of the NFI Information Series published by the National Fisheries Institute and Blue Water Fishermen's Association1525 Wilson Blvd, Suite 500, Arlington, VA 22209.  Blue Water Fishing    For centuries philosophers and naturalists have speculated on the mysteries of tuna, while poets sang its praises as a food. Aristotle recorded the age and growth patterns of tuna in his treatise History on Animals and Pliny the Elder prescribed various parts of the tuna as cures for human ailments. Even the tail, the only part of the fish not consumed by the ancients, was valued -- nailed over doorways toward off evil spirits.  Despite tuna's long-standing popularity in Japan and throughout the Mediterranean region, not until the 1970s did fresh tuna become a desirable food item and significant fishery in the United States. Although widely accepted in canned form for decades, only in recent years have fresh or frozen tuna steaks caught on for their taste and nutritive benefits.  Of course, the big tunas (bluefin, yellowfin, bigeye and albacore) are not the only fish to have experienced an upsurge in popularity due primarily to growing accep-tance of grilling as a preferred cooking technique. Other "big fish" like swordfish, shark and mahi-mahi are increasingly in demand for the same reasons.  These species are firm of flesh, easy to grill and prepare, and appealing to consumers used to a steady diet of land-based proteins like beef. With the growth in consumer demand came the growth of the U.S. pelagic offshore longline fishery and some new attitudes toward commercial fishing in America. Pelagic fish are the free-swimming, open ocean species that grow to hundreds of pounds and live many years. These fish are known for their fighting strength and are prized by both commercial and sportfishermen for their size and their terrific taste. Additionally, because Japanese consumers are willing to pay top dollar for quality fish for sashimi and sushi, some of these spe-cies, especially the tunas, are also prized for their monetary value. A single, large high-quality fish can be worth thousands of dollars on the Japanese market.  The U.S. Longline Fishery  Imagine baiting hundreds of hooks, each set far apart from the next, and feeding out miles of monofilament line in the hopes of catching two, ten, twenty or as many as 60 fish a day. That is what "longline" fisher-men in the Atlantic and Gulf of Mexico must do in their quest to land swordfish, tuna, mahi-mahi and shark as these fish migrate, each year, along the East  Coast of North America.  Environmentally Friendly Gear  Longlining is one of the most conservative methods of harvesting fish. Prior to its development, pelagic fish were caught by handline, rod and reel, and harpoon. Longlining combines the quality afforded by "one-at-a-time-handling" fishing methods with the conservation and efficiency of the "hook-and-line" longlining method.  Longline gear consists of a continuous mainline supported by float lines, with regularly spaced leaders that end with baited hooks. The original "Yankee" gear consisted of a heavy nylon mainline with 1,200 to 3,000 hooks spaced at shallow depths along 15 to 40 miles. Fishing effort was focused across large geo-graphic areas where swordfish aggregate – between currents along frontal zones.  Newer "Southern" gear consists of monofilament mainline and was developed to reduce drag and visibility. Lengths of float lines and leaders were increased to maximize fishing depths, and the number of hooks were reduced to prevent tangles. These modifications decrease by-catch.  Today's longline gear has many conservation benefits. What astonishes many is the spacing between each longline hook -- slightly less than the length of a football field. This reduced number of hooks minimizes the capture rates of non-target species. Smaller hooks and monofilament leaders have allowed sharks to bite off the line, and some large spawning stock species, such as bluefin and swordfish to break off. Additionally, the lighter, longer monofilament gear allows greater movement of captured fish and higher survival rates. Many fish are landed live so the marketable species can be processed quickly to provide a high-quality food product, while nonmarketable species are released alive.  The field of commercial fishing gear technology faces new challenges. Catching the most fish in the least amount of time was the goal of the past. Today, however, conservation and management issues are changing the industry's focus. Meeting conservation goals and adopting sustainable harvesting practices now take precedence over increasing harvest. According to a University of Rhode Island gear specialist, "technology is already too efficient at harvest-ing." Today's gear must reduce the incidental capture of nonmarketable species. Innovative longliners are meeting this goal by modifying vessels, fishing methods, and gear to concentrate on target species and eliminate bycatch.  At Sea  Depending on the size and type of fishing vessel, longliners normally load supplies and provisions for trips lasting anywhere from 10 to 30 days. Fishermen travel as far as 1,500 miles from shore seeking areas where the greatest numbers of targeted fish concentrate. Longline fishermen work a harvest area extending from the north coast of South America, through the Caribbean and Gulf of Mexico, through the Azores and up through the central north Atlantic Ocean.  The East Coast of the United States has three distinct water masses which dictate the distribution of pelagic fish. Nearest the shore is the "shelf"zone -- the water that follows along the coast out to the Continental shelf. Beyond the shelf, is the "slope" zone which moves over a sort underwater plateau. Finally, the third zone is the Gulf Stream itself, a warm water current which flows up the Coast passing along the edge of the continental shelf by Georges Bank.  Along the edge where these water masses converge they form eddies and temperature vortices which contain some of the most fertile food supplies for the pelagic fish and their food species. A knowledgeable longliner will track these "frontal" areas on his vessel by using fax weather reports and satellite photographs detailing the movement of these streams of water. The longliner then "sets" his lines along the areas where the streams are in flux, looking in particular for the areas where the waters are eddying toward the shore, because the temperatures are likely to remain warm longer, and thus a more reliable food source for these fish.  Satellite photographs of longliners working the Atlantic coast show the gradual migration north from January through September every year. After September, ocean storms are more frequent, so fishing effort tends to diminish somewhat. After December the peak season for harvest will have passed and with it the higher fat content that makes these species so desirable.  The U.S. Longliners -- A Special Breed  Longliners are independent individuals who, if willing to work hard, can succeed and survive in today's industry. Each day longliners are consumed with the job of setting the gear, and then hours later, hauling the catch. Live, nonmarketable species are tagged and released. Marketable species are immediately processed on board -- bled, gutted, dressed, and packed in ice. The longliners "one-at-a-time" method of catching and handling fish maintains the high-quality products demanded here and abroad.  The days at sea are exhausting, but satisfying for the men and women of this industry. However, not every trip is a success. The cost of operating a fishing boat has skyrocketed ($12,000 for a small boat to as much as $35,000 for a large vessel per trip). Depending on the size and type of fishing vessel, longliners normally load supplies and provisions for trips lasting anywhere from 10-30 days. Fishermen travel as far as 1,500 miles from shore seeking productive frontal zones in the central North Atlantic where their target species concentrate.  U.S. fishermen seasonally harvest areas from the south coast of South America to the Azores. But, like most commercial fishermen, longliners are survivors, willing to work brutal hours under grueling conditions and even risk their lives to maintain their independence. Interestingly, few longliners started out as such. Many were once charter boat or pleasure boat captains who realized that they could indeed make a living, with a lot of additional work, at doing what they enjoyed most. Other longliners are fishermen displaced from inshore fisheries, like clamming or striped bass, who heeded the call of the high seas.  Environmental Concerns  The incidental catch (bycatch) of certain protected species, including marine mammals, has become a controversial issue with environmentalists and politicians. Fortunately, interaction between longline gear and marine mammals or sea turtles is extremely rare. Longliners rely on their captain’s experience and knowledge of the harvesting method being used, gear modification, and the particulars of time, area and location to meet selectivity goals. Although longline gear can extend to 40 miles, only 500 to 700 hooks are set along that distance providing an average total daily catch (including fish that will be released) of only 40 to 60 fish. According to observer data, most nonmarketable fish are released alive.  The Current State of Stocks  International management of the highly migratory pelagic species is essential because their populations generally migrate through international waters and are subject to fishery pressure from many nations’ fleets. The U.S. tuna and swordfish fisheries share these resources with many nations, including Spain, Japan, Mexico, Canada and a host of others. Imposing catch restrictions on one country alone while other nations fish the same waters undermines a fair conservation program. The United States along with 20 other nations formed the International Commission for the Conservation of Atlantic Tunas (ICCAT). This organization collects data, conducts scientific assessments and determines conservation programs for the migratory species under its jurisdiction.  Fisheries associations, such as the Blue Water Fishermen’s Association, are now involved in both research and policy discussions. Fishermen are spending more time in Washing-ton to strengthen support for equitable, international management to sustain long-term harvests. Nelson Beideman of the Blue Water Fishermen’s Association believes that "responsible fishermen realize the impor-tance of maintaining natural food resources at optimum levels for maximum sustainable yields — as much for our own benefit as fishermen, as for our children and succeeding generations."  Beideman’s association represents the majority of the longline fishermen in the Atlantic and Gulf of Mexico fisheries. His comments reflect a long-standing belief of the commercial fisherman — that he (or she) is an integral part of the marine ecosystem, and that abuse of that role can cause irreparable damage to the future of the fishery and of the marine environment.