• ‚Äč
    • Share to Facebook
    • Twitter
    • Email
    • Print

September 25, 2009

Fisheries Factsheet

Overexploitation of world's oceans and welfare of non-target marine creatures among concerns

The Humane Society of the United States

The United Nations' Food and Agriculture Organization (FAO) has estimated that 950 million people worldwide rely on fish and shellfish for more than one-third of their animal protein. Over 200 million people depend upon fish as a main source of income, particularly subsistence fishers in developing countries. The Humane Society of the United States recognizes the significant international dependence on fishing as an industry. Our primary concerns are the gross over-exploitation of fish populations, the impact of commercial fishing activities on other, non-target marine creatures, and the growing tendency of governments and industry to blame marine mammal predation for fish stock depletion.

Fisheries over-exploitation
Since the 1970s, fisheries have skyrocketed to unprecedented levels of production. The FAO estimates that 70% of the world's fish species are either fully exploited or depleted. The worldwide fleet of commercial fishing vessels has doubled since 1970 and operates at a loss of 54 billion taxpayer dollars every year. The annual global catch peaked in 1989 at 89 million tons and has currently stabilized at about 85 million tons. This abuse has raised great concern within all areas of the fishing community.

In the past, the world's oceans represented an international common ground and were essentially unregulated. The urgency of over-exploitation problems, however, has escalated localized disputes into international conflicts. Exclusive Economic Zones have been established along coastal borders to restrict foreign fishing, extending up to 200 nautical miles from a nation's shores, and are often forcefully defended.

Additional depletion factors
There are other factors contributing to the decline of the global fish population. As much as one-fourth of the annual catch is lost to spoilage or discarded as bycatch (fish that are under-sized or species of little or no commercial value to a particular fishery, although fish discarded as bycatch in one fishery may be the target species for another). Nets lost at sea continue to catch and kill fish and other marine life. Some fishers use potentially dangerous methods such as dynamite or cyanide to bring fish to the surface, which can heavily damage or destroy ecosystems such as coral reefs.

About 80% of marine pollution is land based. Coastal development has caused environmental degradation of marine ecosystems, including fragile coastal nursery areas used by open-ocean species, with increased erosion, sewage, toxic chemicals, and industrial pollution in rivers. Activities including dredging, oil drilling (and spills), pipe laying, and waste dumping all endanger fish habitats. It is predicted that global warming will slowly raise ocean temperatures. Increased ultraviolet radiation from ozone depletion threatens many species. Nuclear pollution in parts of the world also harms marine life. In addition, human introduction of exotic species threatens native populations.

Risk to non-target species (bycatch)
As a conservative estimate, more than 30 million tons of marine mammals, sea turtles, seabirds, sharks, and other unwanted fish are thrown back into the oceans, dead or dying, annually. The actual number is almost certainly far higher. Methods used by large-scale fisheries often prove deadly to the many other marine creatures who share their home with commercially targeted fish species. Some fisheries use large nets with small mesh, trapping or fatally wounding many non-target species. Other gear with high bycatch rates include "longlines" and "bottom trawls." One of the worst fishing methods is drift-netting; a drift-net may be miles long, with an all-but-invisible plastic mesh that ensnares everything in its path. The United States now requires other nations to restrict drift-net fishing if they wish to export fish or fish products (such as coral) to the United States.

Significant negative interactions occur between fisheries and marine mammals such as porpoises, dolphins, whales, sea lions, seals, manatees, and dugongs. A particularly bad example of this occurs in the eastern tropical Pacific Ocean, where dolphins are deliberately chased and encircled by huge nets used to catch the tuna swimming below them. Millions of dolphins experience harassment, trauma, and injury each year and thousands die as a result of the use of this fishing method. Another critical interaction involves the highly endangered northern right whale and New England fisheries. Only about 300 of these great whales remain; every one entangled in a fishing net or struck by a vessel is a disastrous loss to the population.

The vaquita, a highly endangered harbor porpoise, is killed in gillnets in the Gulf of California. If this source of mortality is not reduced or eliminated, the vaquita could become extinct in the near future. The critically endangered Chinese river dolphin, or baiji, is also threatened with imminent extinction from entanglement in fishing gear, as well as from habitat degradation and loss.

At least 40,000 sea turtles are killed annually in shrimp trawls. Sea turtles are susceptible to high egg and early-life mortality and rely heavily on adult survival. In 1991, the U.S. Fish and Wildlife Service and the National Marine Fisheries Service estimated that there were fewer than 1,000 nesting females of the highly endangered Kemp's Ridley turtle. All five sea turtle species found in U.S. waters are threatened or endangered. In 1989, regulations were established requiring all boats in the Gulf of Mexico to use Turtle Excluder Devices (TEDs) to reduce sea turtle mortality in shrimp trawls. Other nations must also use TEDs if they wish to export their shrimp to the U.S.

Another problem associated with bycatch is the water surface discard of unwanted fish, which attracts seabirds and other scavengers. Bait and catch in nets and on lines may also prove to be a fatal attraction to seabirds, including albatrosses and murrelets. Birds and other animals become more vulnerable to entanglement in the fishing gear that provides these meals; the crew aboard the vessels may also shoot at them to protect catch. Scavenging animals may also abandon their natural foraging behavior. Some become chronic beggars and their health may suffer as a result.

Marine mammal predation
Additional problems arise because many fishers feel their dwindling fish stocks are threatened by marine mammal predation, although declines are most often caused by human over-fishing. Examples: Government officials and commercial and sport fishers blame California sea lions for the critical decline of steelhead trout at Washington State's Ballard Locks, which is more accurately attributed to a complex series of factors having little to do with sea lion predation. The Canadian government, virtually without basis, charges that harp seals are preventing the recovery of severely over-fished north Atlantic cod stocks. In Japan, dolphins are killed to eliminate perceived competition for various fish stocks and their meat is often sold as a substitute for whale meat. Norway claims that minke whales compete with commercial fisheries for small, schooling fish, using this as an additional excuse to justify its shameful commercial whaling.

What you can do
You can help The HSUS reduce fisheries over-exploitation, non-target bycatch, and harmful interactions with marine mammals. Contact your Senators and Representative and ask them to support legislation that protects fish and other marine wildlife through provisions that prevent over-fishing, limit allowable bycatch, reduce and eliminate the use of destructive fishing gear and practices, and protect habitat. Urge them to maintain a strong Marine Mammal Protection Act (MMPA) and Magnuson Fishery Conservation and Management Act. Ask them to repeal the MMPA's 1994 amendment permitting lethal removal of seals and sea lions perceived to conflict with fisheries, as it is counter to the protective spirit of the MMPA. Ask them to support strong international enforcement of laws prohibiting the use of over-sized drift-nets, the strip-miners of the oceans. Ask them to support a law that defines "dolphin-safe" tuna as tuna caught without traumatically encircling dolphins with mile-long nets.

Educate yourself on which fish stocks and species are over-exploited and depleted. Write letters to fish companies urging them to adopt practices that help protect these species.

  • Sign Up
  • Log in using one of your preferred sites
    Login Failure
  • Take Action