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17 Drift longlines rigged to catch large pelagic fish in the Pacific generally consists of a 20 - 69 mile central main line made of 700 lb. test monofilament line. Attached to this central line are thousands of branch lines, or gangions, with a large hook on one end and a clip on the other to attach it to the main line. An average set will place 1500 to 2000 hooks in the water at any one time. Atlantic longlines are shorter and average roughly 500 hooks with each set. The hooks are baited with squid, mackerel, or some other similar baitfish. In addition to the bait, chemical light sticks are often used to attract fish. The loss of light sticks is not uncommon and constitutes a source of marine pollution that poses a mortal threat to marine mammals, seabirds and turtles which ingest them. A vessel may use up to 5000 light sticks per trip. Periodically, floats, radar reflectors, and radio beacons are attached to the main line to allow it to sink to the proper depth and be tracked by the boat. Gear is typically set out and left to "soak" for 12 or so hours before being retrieved.

Drift Gillnets

Gillnets are among the most indiscriminate fishing gear in use. Gillnets are vertical walls of netting up to 2.5 kilometers in length, which are designed to entangle fish by their gills, and thereby prevent their escape. Gillnets can be anchored in a fixed location or left to float freely with currents, as is the case with drift gillnets. Gillnets targeting swordfish, sharks, and tuna are fished at or near the surface. U.S. drift gillnets for large pelagic fish average just over a mile in length and 60 to 120 feet deep. Gillnets entangle and kill anything larger than the net's mesh size. Most fish caught in gillnets suffocate while entangled marine mammals, seabirds, and turtles drown. In the Atlantic gillnet fishery, which targets tunas and swordfish, the indiscriminate nature of the gears causes it to catch numerous species, including: 4 species of skates and rays, 10 species of coastal sharks, 6 species of pelagic sharks, 12 species of tunas and billfishes, 19 other species of fish, 3 species of sea turtles, 8 species of seabirds, and 16 species of whales and dolphins.

This fishery has recently been temporarily closed because of its bycatch of endangered northern right whales.

In 1991, the United Nations banned the use of large scale high seas driftnets over 2.5 kilometers long. Prior to the UN driftnet ban, these nets were of enormous proportions reaching lengths of 40 to 60 km. Each day thousands of kilometers of drift nets are legally set in individual lengths under 2.5 km, which entangle and kill indiscriminately. Despite the UN ban on large scale drift nets, serious concerns exist regarding ongoing violations.

Mesh size determines the size of animal caught in the net and may range from 3.4 inches for squid to 22 inches for swordfish and shark. As with longlines, to increase their effectiveness when targeting swordfish, driftnets are often strung with a series of chemical light sticks. Radar reflecting buoys are attached to the net at regular intervals, to allow the fishing vessel to more easily locate the net.

In the North Pacific squid driftnet fishery over 100 species of animals including fish, sharks, seabirds, sea turtles, and marine mammals have been reported as bycatch, with most being discarded. The number of whales and dolphins that are killed as bycatch every year in the California swordfish drift gillnet fishery is about equal to the number of all whales and dolphins in public display facilities, such as zoos and aquariums, in the entire United States.

19 Gillnets are associated with other environmental problems as well, including a high dropout rate -- dead or dying fish loosely ensnared by the net which become dislodged, or "drop out" of the net, either before or during the retrieval process -- and "ghost-fishing." Ghostfishing occurs when gear is lost or discarded at sea and continues catching and killing animals.

Purse Seines

A purse seine is a large net used to encircle fish that can be drawn closed or "pursed" at the bottom while the top edge of the net floats on the surface. During purse seine operations fish are located by sonar, an on-board lookout, or spotter aircraft. The mother vessel dispatches a powerboat with one end of the net attached to it, which subsequently encircles the school of fish, preventing lateral escape. Once encircled, the bottom of the net is then pursed by hauling on a cable which runs through steel rings at the bottom of the net, thus preventing downward escape of the fish. The result is a large bowl shaped net from which escape is impossible. The wings, or ends of the net, are then pulled in, shrinking the net and concentrating the fish. The fish are then retrieved, typically by means of a suction pump or smaller net. Per unit of effort, purse seines are the most efficient fishing gear, capable of wiping out an entire school of fish (40-50 tons) in one set. With proper precautions and gear restrictions in place, purse seine fisheries for certain highly migratory species can be a clean selective fishery. If employed without the necessary caution, purse seines can devastate the marine environment, as evidenced by the Eastern Tropical Pacific tuna fishery:

The annual slaughter of hundreds of thousands of dolphins in the Eastern Tropical Pacific tuna purse seine fishery during the 1970s and early 1980s represents one of the most dramatic examples of bykill. The debate over reducing dolphin mortality in this tuna fishery became known as the "tuna-dolphin" debate. Subsequent changes in fishing techniques dramatically reduced the mortality of dolphins, but unintentionally caused the bycatch of sharks, juvenile billfish and tunas, sea turtles and other non-target species to climb exponentially. In 1993 and 1994, with dolphin bycatch mitigation techniques in place, the estimated bycatch for the Eastern Tropical Pacific purse seine tuna fishery was estimated at almost 6.6 million animals. The devastation of fish populations due to dolphin mortality mitigation efforts exemplifies the insidious nature of bycatch and the fact that bycatch is not limited to only glamorous species such as dolphins. As a result, in part, of the amount of bykill taken due to dolphin mitigation measures, new techniques have been developed to protect both dolphins and fish in this fishery.

Selected Fisheries For Giant Ocean Fish

Hawaiian Longline Fishery

There are currently 98 longline vessels regularly operating in and around Hawaii. The vessels engaged in this fishery range from 43 foot wooden boats up to 165 foot modern steel ships capable of fishing for periods of 2-3 months. The primary targets in the Hawaiian longline fleet are swordfish and sashimi grade yellowfin and bigeye tunas, all of which are high value products. There is a considerable bycatch in this fishery, typically consisting of six species of sharks (blue, mako, thresher, brown, Galapagos, and tiger), mahimahi (dolphin fish), wahoo, barracuda, moonfish, pomfrets, oilfish, two species of albatross (laysan and blackfooted), dolphins, and 5 species of turtles. Occasionally, whales, additional species of sharks, turtles, and two seal species, including the endangered Hawaiian monk seal, are also taken as bycatch.

All species of sharks taken in this fishery are taken as bycatch. The volume is horrifying. From 1991 through the second quarter of 1997 694,653 sharks were unintentionally caught in the Hawaiian longline fishery.

20 The number of sharks caught in this fishery peaked in 1993 at 154,608.

21 Since that time the number has declined to about 101,000, and there are indications (declines in catch per unit effort) that the populations may be declining.

Increasing demand in Asia for shark products has resulted in a dramatic increase in retention of sharks caught as bycatch. The percentage of sharks kept in part or whole has risen to 53.4%, from 3.2% in 1991, a 17 fold increase over a six year period.

22 Approximately one percent of sharks retained in the Hawaiian longline fishery are landed whole, the remaining 99% of those retained are finned.

23 Finning is illegal in the U.S. Atlantic shark fishery, but despite mounting opposition, is still allowed in the Pacific for fishermen from the U.S. and other countries. The amount of waste produced by this practice is phenomenal. In 1995, of the 3.5 million pounds of sharks landed in Hawaii, only 48,900 pounds, less than 1.4% of the total landed weight, were utilized, yielding a total value of $830,000.

24 The damage done to regional shark stocks by the unintentional annual removal of more than 100,000 of these apex predators is unknown. What is known is that regional shark populations around the world have universally collapsed when subjected to sustained fishing pressure, regardless of whether the pressure was a result of a directed fishery or of bycatch. Many overfished shark stocks have never recovered, and recovery can take decades. Without implementing measures to reduce the number of sharks caught incidentally in the Hawaiian longline fishery, it will undoubtedly collapse as well.

The number of sea birds and turtles caught as bycatch in this fishery is climbing at an alarming rate. In 1996 an estimated 625 laysan albatross and 1189 black-footed albatross were caught as bycatch in this fishery.

25 The number of laysan albatross hooked in just the first quarter of 1997 was 1.5 times greater than the bycatch for all of 1996, while the bycatch of black-footed were at roughly the same level for the same period last year. Additionally, the number of albatrosses and turtles being hooked is rising faster than the increase in the number of hooks being set. Through the first quarter of 1997, the rate at which loggerhead sea turtles in the Hawaiian longline fishery were being hooked was higher than at anytime in the past three years.

26 U.S. Atlantic Drift Longline Fishery
The U.S. Atlantic longline fleet consists of approximately 300 active vessels which primarily target swordfish, yellowfin tuna, and to a lesser extent, bigeye tuna. Fishing effort in terms of numbers of hooks fished has increased 70% over the last decade. In 1993, according to vessel logbooks, over 360,000 fish, representing nearly 70 species, were captured on longline hooks. Of this total, about half were thrown back into the sea, and more than half of these were reported dead when returned to the water. An unknown number of those discarded alive died of trauma or predation afterward.

Among the dead discards are tens of thousands of juvenile swordfish; thousands of marlin and sailfish; thousands upon thousands of sharks; and hundreds of rare giant bluefin tuna.

In 1996, an estimated 40,000 juvenile swordfish were discarded dead by U.S. Atlantic commercial fishermen;
83% of the female swordfish and 36% of male swordfish caught in 1995 by the U.S. Atlantic commercial fishing industry were sexually immature; caught before they were able to spawn even one time.

27 In 1993, longliners fishing for swordfish in the northwest Atlantic caught 50,000 blue sharks, twice their catch of swordfish. All were thrown overboard; nearly half were dead.
In 1995, 1,349 rare bluefin tuna were caught as bycatch and discarded dead.
Atlantic swordfish, blue and white marlin, bluefin tuna, and 21 species of sharks are designated overfished by the National Marine Fisheries Service (NMFS) and international fisheries authorities. Although regulations are in place to limit the landings of these species, they do not prevent these overfished species from being killed on non-selective longline hooks. As a result, fishing mortality remains substantially higher than recommended by scientists and impedes efforts to rebuild the overfished populations to optimum levels.

According to Ocean Roulette: Conserving Swordfish, Sharks, and other Threatened Pelagic Fish in Longline-Infested Waters, a new report by the National Coalition for Marine Conservation, the need to control the use of non-selective longlines and reduce the associated bykill have been recognized for over two decades, yet the problem has only worsened because there are fewer fish to catch, and the fisheries have changed. The longline fisheries have evolved into opportunistic, multi-target fisheries as many large pelagic fish populations in the Atlantic Ocean have declined due to overfishing -- most are now at historic lows and several are severely depleted. Fishery managers are rendered incapable of effectively controlling fishing mortality for any single species as fishermen take advantage of the non-selectivity of their gear to catch a wide range of marketable fish.

The report concludes that traditional management strategies that attempts to control fishery outputs, like what fish are legally landed and in what number, are not effective for the longline fisheries. The report states that management must regulate inputs; the gear itself and where, when, and how it is used.