published on March 5, 2007
This is a guest article from scuba diver and shark enthusiast Patrick. He regularly blogs about shark and whale conservation as well as on other environmental topics @ the Shark Bait Blog.
The instantly recognisable theme tune of the movie 'Jaws', masks the fact that Sharks of all species have a great deal more to fear from Homo sapiens than the other way round. More people are killed by lightning strikes, falling coconuts and the domestic dog each year than are attacked (let alone killed) by sharks.
In contrast the gigantic number of sharks killed by the international shark fishing industry (much of it destined for the Shark Fin soup market) are so mind bogglingly vast that the figure is in danger of losing its impact through its sheer size. The IUCN's Species Survival Commission, Shark Specialist Group estimates that tens of millions of sharks die worldwide each year as a result of directly targeted fisheries or exploitation of by-catch, in particular the long lining Tuna fisheries.
Unlike some other commercially targeted fish species (although it is becoming ever more evident that the majority of fisheries in international waters are currently being unsustainably overexploited) the vast majority of Shark species simply do not reproduce anywhere near fast enough to sustain the level of exploitation of modern industrial commercial fisheries.
There are a number of recent historical examples of shark populations fished to commercial extinction and since many schooling shark species congregate in single sex groups the possibility of real extinction of localised shark populations is often the result.
Gavin Maxwell is famous for writing the book Ring of Bright Water about his pet otter, what is not so well known is that during the 1950s, Mr Maxwell owned a Basking shark fishing company on the island of Soay, off the coast of Scotland and in the space of a few years using relatively primitive harpoon equipment, decimated the local Basking shark population; ruining his business in the process.
The history of the international porbeagle shark fishery in the northwest Atlantic (NAFO subareas 3 - 6) repeats this pattern. in 1961 the fishery was started on a previously unexploited population of Porbeagle sharks, peaked in 1963 and had already crashed by 1965; the population has not significantly recovered. Campana et al. Population dynamics of the porbeagle in the Northwest Atlantic Ocean. North American Journal of Fisheries Management 22:106-121, (2002).
Bull sharks are renowned for their ability to tolerate fresh water (the Bull Shark has been recorded some 2,600 miles (4,200 kilometres) upriver from the mouth of the Amazon) and until recently Lake Nicaragua in South America actually had a resident population of breeding Bull sharks... however the Nicaraguan dictator Somoza permitted a shark-fin processing plant to be built on the shores of the San Juan River. So during the 1970s, thousands of sharks were caught and killed each year then processed through this Japanese plant, as a result the shark population collapsed; few if any sharks now remain. The last media reports of a sighting date back to the year 2000, there have been few recent scientific investigations and the shark population is considered to be virtually wiped out.
These are just three specific examples, far more worrying is the fact that now vast areas are being affected.
A report by Julia Baum and Ransom Myers published in Nature in 2004 found that the Oceanic White Tip, once one of the most common sharks in the world; according to their census in the Gulf of Mexico are now almost extinct there, over the past 50 years Oceanic Whitetip numbers in the Gulf have crashed by more than 99%. Baum, J. K. & Myers, R. Shifting baselines and the decline of pelagic sharks in the Gulf of Mexico. Ecology Letters, 7, 135 - 145, doi:10.1111/j.1461-0248.2003.00564 (2004). The crisis had not been noticed before simply because of a lack of data. Myers found a government survey of the number of whitetip sharks accidentally caught on tuna fishing lines in 1954 in the Gulf of Mexico. No further record was kept of the sharks' numbers until 1992, because the sharks weren't being 'intentionally' fished in the Gulf.
The study adds to a body of work that points to a massive decline in numbers of large predator species in the oceans. Baum and Myers previously found that silky sharks in the Gulf of Mexico have declined by around 90% since the 1950s. And hammerhead shark numbers in the Atlantic have plummeted by 89% in the past 15 years. Baum, J. K. et al. Collapse and conservation of shark populations in the Northwest Atlantic. Science, 299, 389 - 392, (2003). "Sharks are in a global extinction crisis," says Myers. "Wherever you look around the world the story is the same."
Myers has called for a worldwide ban on shark-finning. Canada, Australia and the United States have outlawed the practice, although enforcement has proved difficult and anti-finning laws in other countries have in many cases been based on the short term economic requirements of fishing industry interests rather than long term conservation. The World Conservation Union (IUCN) is spearheading a campaign for countries to recognize the damage caused by the trade in shark fins.
Despite an increasing level of publicity over the Shark finning Industry in the international media, more action is desperately needed in 2007.
Expert findings show even the fastest, widest ranging sharks are threatened by overfishing as more species added to IUCN Red List of Threatened Species: More oceanic or "pelagic" sharks are being added to the IUCN Red List of Threatened Species based on the findings of this week's international expert workshop, convened by the IUCN Species Survival Commission (SSC), that examined the conservation status of these highly migratory sharks against Red List criteria.
"The qualities of pelagic sharks - fast, powerful, wide ranging - too often lead to a misperception that they are resilient to fishing pressure", said Sarah Fowler, Co-Chair of the IUCN SSC Shark Specialist Group (SSG). "This week, leading shark scientists from around the world highlighted the vulnerability of these species to overfishing and concluded that several species are now threatened with extinction on a global scale." More oceanic sharks added to the IUCN Red List @ http://www.sharktrust.org/content.asp?did=26868
Many shark species are slow to mature and produce few offspring which means they are simply unable to support international fishing industry exploitation.
Whatever the claims of quacks and snake oil salesmen, shark products have NEVER been medically proven to prevent, let alone cure cancer. The Truth About The Shark Cartilage Scam @ http://www.nautilusproductions.com/sandtigersharks/scam.html
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