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Industrial Longline Fishing: A War on Fish
by Todd Steiner
Among the greatest of the threats to our future is the decline of our planet’s greatest resource, the oceans. The United Nations Food and Agriculture Organization reports that 70% of marine fish species are on the brink of collapse due to overfishing. Meanwhile, globally, 44 billion pounds of fish are discarded every year—25% of the entire world catch.
A primary threat to those ocean resources comes from industrial longline fishing, an industry that sets over 5 million baited hooks every day (almost 2–10 billion annually), creating a curtain of death. These lines catch anything that bites or is unfortunate enough to get hooked while swimming in their path.
In addition to the impact this fishing technology has on target fish species, the collateral damage is enormous and includes sea turtles, seabirds, dolphins, whales, sea lions, marlins, and sharks. These marine species, critical to ecosystem dynamics, are viewed as expendable by an industry that seeks to maximize profits without taking into account the tremendous environmental costs of its practices.
The collateral damage does not end here. Humans are victims, too, and include the coastal communities in the developing world whose fishers are finding their local fishing grounds devoid of fish, and, surprisingly, US consumers who are being offered a regular year-round supply of mercury-poisoned fish.
Industrial longlining technology
Technological advances have given humans the ability to harvest fish beyond the capacity of species to sustain themselves, and longlining can be considered a poster child of high tech advances.
Longlining fishing gear consists of a 60-mile main line attached to 2,000 branch lines, each up to 1,200 feet long and which have deadly hooks baited with squid or fish. Utilizing giant winches, these vessels can haul in the more than 500 miles of line deployed each set, laden with hundreds of fish and other marine species.
…longlining is often a marginal commercial enterprise at best.
With a small crew of three to four people, these powerful vessels can remain at sea for months, freezing their massive catches. These vessels have a vast range, and use high tech sonar and communication tools to locate and chase fish around the globe.
High seas (pelagic) longlining primarily targets swordfish and tuna. Recent economic studies show that longlining is often a marginal commercial enterprise at best. On average, Atlantic longliners lose $7,000 a year after all costs are added up, including depreciation on the vessel. Because longline fishers must pay off huge mortgages on their vessels, they continue to fish, hoping for a big catch. The net losses are on average; some efficiently operating longliners do make handsome profits. Fishing subsidies, such as low or no interest loans to purchase vessels and subsidized fuel costs, keep many of these vessel owners afloat.
A study by professor Peter Tyedmers of Canada’s Dalhousie University compares the material and petroleum energy required to power a wide variety of industrial fishing vessels with the energy contained in the harvested edible fish protein.
“…it is now common for direct fossil fuel energy inputs alone to exceed nutritional energy embodied in the catch…”
Tyedmers concludes, “it is now common for direct fossil fuel energy inputs alone to exceed nutritional energy embodied in the catch by at least an order of magnitude.” Shrimp, tuna and swordfish are at the top of the list for the most inefficient “edible protein return on investment.” Specifically, Tyedmers lists longlining as least efficient technology.
Targets: Swordfish and tuna threatened
The target species of longlining are primarily top-of-the-food-web predatory fish, such as swordfish and tuna. These are the really big fish, many of which live for decades and play keystone roles in ocean ecosystem dynamics. Just as the destruction of wolves in North America caused deer populations to explode, followed by overgrazing and then the crashing of the deer populations themselves, the destruction of populations of top predatory fish have similar repercussions in ocean food webs.
For example, the swordfish is a magnificent species that can grow to 15 feet in length, weigh up to 1,200 pounds and live longer than 25 years. Prior to modern longlining, swordfish were commercially harvested individually with harpoons.
In the Atlantic, at the turn of the last century, the average swordfish landed weighed 300 to 400 pounds. By 1963, the average fish landed weighed 266 pounds, and in 1996, the average fish weighed only 90 pounds. The facts that the size of fish being harvested continues to shrink, and that almost all individuals are juveniles, are classic symptoms of overfishing.
Several species of tuna sharing similar life history traits are showing similar declines. The largest tuna, bluefin, has been fished to near extinction. Recent scientific studies suggest that top predatory fish populations have decreased by 90% in the past 50 years, and longlining has been identified as the primary cause.
Collateral damage: Many marine species face extinction from longlining
Off-target Fish Species. Dozens of species of top predator fish including many shark species and swordfish-like marlin species are also facing crashing populations due to longlining. Like the target species themselves, these species’ populations have also dropped by 90% or more.
Leatherback Turtle. Leatherbacks, the largest living reptile on Earth, growing to a length of nine feet and weighing up to 2,000 lbs., are also victims of longlines.
As longlining has increased, the number of Pacific leatherback females that have safely returned from the oceans to their nesting sites has dropped dramatically.
At Mexiquillo, historically Mexico’s most important nesting beach, an average of only four females returned to nest in recent years, down from almost 5,000 in the 1980s.
Unfortunately, the situation is the same throughout the Pacific. Industrial fishing techniques are driving the Pacific leatherback sea turtle to extinction.
Leatherback and loggerhead turtles, already listed under national and international law as endangered, have become the focal point of legal actions against the longline industry in the United States.
Flying Victims. Seabirds, especially albatross, are killed by the hundreds of thousands each year by longlining. These birds dive at the baited hooks as they are first deployed, and once they become hooked they are pulled to a watery grave hundreds of feet below the surface. One species in particular, the black-footed albatross, has recently joined the list of species that may become extinct in the near future because so many are being killed by longliners. Environmentalists have recently petitioned to have this species added to the US Endangered Species list.
Consumers poisoned by mercury-tainted fish
Top predator fish, especially swordfish, sharks and tuna, that eat lots of smaller fish, bio-accumulate poisonous mercury that is harmful to human consumers.
Mercury contamination of seafood is a persistent public health threat. Mercury accumulates in the human liver, kidney, brain and blood. Even at low levels, it can harm a child’s developing nervous system, leading to loss of motor skills, mental retardation and other birth defects.
One in 10 women enters pregnancy with high methylmercury levels. Recent studies show that mercury contamination can cause infertility, kidney failure, cardiovascular collapse and genetic damage in adults.
Though some amount of mercury is naturally found in the environment, according to the Environmental Protection Agency an additional 48 tons of mercury were released in 1999 alone from utilities burning coal and other fossil fuels, the primary source of mercury in the environment. Mercury is also released through mining operations, hazardous-waste incineration, oil refining and medical waste.
Today, the Federal Food and Drug Administration and the Environmental Protection Agency recommend that women of childbearing age and children not eat swordfish or shark and severely restrict their intake of tuna and other fish species.
Local communities under siege
Probably one of the least documented assaults by the industrial longline fishery is its impact on local communities that rely on low-tech fishing technology. What is clear is that industrial longline fishing is stripping the oceans not to feed the human population that is in need of higher amounts of protein; the target fish are high-cost consumer products that end up on dinner plates in the US, Japan and Europe.
By 1963, the average fish landed weighed 266 pounds, and in 1996, the average fish weighed only 90 pounds.
Better information is needed on the impacts of this fishery on small-scale fishing communities to strengthen the movement for creating sustainable oceans that support human needs and marine biodiversity.
Environmentalists fight for reform
Environmentalists have mounted an aggressive campaign to reduce the impacts of longlining on marine species and ocean ecosystems, especially on US - flagged vessels.
Lawsuits using the Endangered Species Act, Marine Mammal Protection Act, Migratory Bird Treaty Act and Magnussen Fisheries Act over the killing and injuring of leatherback and loggerhead turtles, false killer whales, black-footed albatross and marlin have had some success, with the permanent closing of the California longline fishery, a four-year closure of the Hawaiian swordfish longline fishery, and time area closures for the Hawaiian tuna longline fishery and the Atlantic longline fishery.
Environmentalists are also petitioning to have additional species listed under national and international endangered species lists including bluefin tuna, great white sharks, albatross and other species. Time and time again, with each of these species, longlining is implicated as playing a major role in the species’ demise.
Additionally, environmentalists have pushed for better consumer labeling of the hazards of eating mercury-tainted seafood to protect the health of women and children, and to encourage sustainable seafood consumption, which for the developed world means consuming less seafood and eating lower on the ocean food chain.
Furthermore, more than 600 of the world’s leading scientists and over 100 non-governmental organizations have published an open letter to the United Nations, calling for a ban on pelagic longline fishing in the Pacific.
There is a precedent for such action. In 1993, the UN banned drift-net fishing on the high seas. The nets had caused a similar crisis, drowning hundreds of thousands of dolphins and other marine species. Unfortunately, after the UN ban many of these vessels replaced their drift nets with longlines.
Environmentalists are also working on strategies to use trade sanctions to rein in longline fisheries.
Cross-over: Building solidarity in the movement for a sustainable future
The cross-over issues of marine species protection, human public health, air pollution from burning fossil fuels, and solidarity with fishing communities in the developing world is helping to build multi-issue coalitions necessary to create a sustainable world for current and future generations.
Todd Steiner is a biologist and director of Turtle Island Restoration Network. For more information, visit http://www.seaturtles.org/ and http://www.GotMercury.org/
[27 dec 04]