Bleeding the Oceans Dry - WildAid

P r e s s u r e s o n s h a r k sCommercial fishing gearNet illustrations Courtesy of FAO/ Fisheries and Aquaculture DepartmentLong linesLonglines are often used bytuna, swordfish, mahi mahi andbillfish fisheries. Thousands ofbaited hooks may be set off amain line that can be kilometreslong. As many as 10-20 millionblue sharks are caught asbycatch by longlining effortseach year 16 .EntanglingnetsDriftnets are vertical, weightednets which float in the currentand left to drift for hoursor even days. Despite a UNmoratorium on their use, as wellas numerous national bans, thismethod is still used by manycountries. It is particularlywasteful – with an estimated85% of catch thrown back intothe sea 17 .Purse seinenettingPurse seine fishing is primarilyused for catching schooling fishsuch as sardines. A purse seineis a large wall of netting thatencircles a school of fish.The bottom of the netting is thenpulled closed (like a drawstringpurse), trapping the fish. Sharkbycatch in purse seine fisheriestargeting tuna totalled up to1,500 tons in 2004 18 .TrawlingTrawlers drag a cone-shapednet behind a boat. With variousmodifications this can be set toany height in the water column.This is considered the mostindiscriminate form of fishing,© Fiona Ayerst/ Marine PhotobankProtecting our beaches?Beach-nets are designed to trap and kill sharkspecies that are considered dangerous to beachusers. They have been criticised for giving theillusion of complete protection of bathers andsurfers by acting as a barrier to sharks, whenin fact 40% of sharks are caught on the beachside of the nets on their way back out to sea 19 .As with commercial fishing gear, the nets catchboth target species, such as great whites,bull and tiger sharks, and non-target species(harmless to humans) such as reef and nursesharks 20 . Along the coastline of KwaZulu-Natal,South Africa, anti-shark nets catch an average of628 sharks, 237 rays, 58 turtles and 53 dolphinsannually 21 .Ghost netsGillnets tend to be in fixedposition. Before their use wasbanned in the high sea, typicalbycatch rates for pelagic gillnetswere of about 30-40% of thetotal catch 6 .with bycatch rates ranging from60% of the target fish as in sometemperate groundfish fisheries, toover 10 times the amount of targetspecies in some tropical shrimpfisheries 6 . Bottom trawling alsodamages the ocean floor.Lost and discarded fishing gear makes up about10% of all marine litter 22 . The gear is designedto be extremely durable, and is often made ofsynthetic materials that do not biodegrade. Thismeans that lost and discarded fishing gear cancontinue to attract marine organisms, ensnaringthem and killing them, indefinitely. This isknown as ‘ghost-fishing’. One study based inthe Puget Sound, Washington, calculated that adiscarded net could potentially catch an averageof 92 invertebrates, 13 fish and seven seabirdseach month 23 .Right: An illegaltrawler fishingin Sierra Leonewaters.© Environmental Justice FoundationAbove: A bullshark is killed inan anti-shark netoff Durban1 0 b l e e d i n g t h e o c e a n s d r y