Elasmobranch Conservation

Humans are victims of their own efficiency, able to deplete vast ecosystems in their search for the almighty dollar. It was impossible to wipe out the Buffalo of the Great Plains without anyone noticing, however a similar depletion happens every day with the oceans fisheries and no one on land seems to blink an eye.

Anon.

Finning
History of Shark Fisheries
ByCatch
Shark Fishing for Sport

Sharks are of vital ecological importance in our oceans that fulfill the role apex predators in the food chain helping the ecosystem by removing  weak and unhealthy animals. Like most apex predators if there were too many of them then every other fish in the sea would be eaten. To counter this, nature has made sure that there aren’t too many sharks in the world by making them long lived, slow growing and late to reproduce. This ensures their numbers never grow too fast and allows them to fulfill their ecological niche in the environment superbly.

However, it is these life traits that make elasmobranchs  incredibly poor at withstanding sustained fishing pressure. This pressure that has been building over the previous decades has come about as a result of high demand for sharks fins, liver and their cartilage. Many sharks are also oceanic in nature wandering across vast tracts of ocean, across national boundaries. This means that they are subject to much un-regulated fishing pressure of many nations.

As a result  sharks alone are being decimated at around 270,000 sharks a day. Their numbers have declined dramatically to less than 30% of their numbers just 2 decades ago. Their decline in numbers and their life history i.e. slow reproductivity has prompted great concern. The International Union for the Conservation of Nature (IUCN) have created a Shark Specialist Group in the wake of several species being listed on their Red List. This is the world's most comprehensive inventory of the global conservation status of plant and animal species. The IUCN Red List is set upon precise criteria to evaluate the extinction risk of thousands of species and subspecies.
Sharks and Rays  extreme susceptibility to overexploitation mean that  if you reduce sharks numbers, for instance through overfishing, it will take a significant amount of time to replenish their stocks.  In comparison to teleost (bony fish) fisheries for species that have high fecundity and a relatively quick life history, the shark and ray fisheries are far less stable because the teleosts are able to replenish their numbers at a far higher rate although they are by no means safe from exploitation. In addition, as with many species, the larger species of shark and ray are more fecund than their younger sexually mature males, able to produce significantly more offspring than younger adults. Targeted shark fisheries however remove the larger sharks first before the smaller adults, removing with them the most effective way to  replenish a depleted population.

In addition there is an enormous problem with bycatch, this term refers to the countless other wasted species that are caught in addition to the targeted species. On the high seas (an area beyond an individual countries control) fishermen use ruthlessly efficient techniques to capture fish. One of these techniques known as long line fishing allows miles and miles of monofilament line suspended by floats  with baited hooks underneath. They are left to drift in the ocean, catching turtles and sharks amongst other organisms. The sharks are a common form of bycatch although when they are captured they are rarely identified to species level and this means that accurate population statistics from fisheries data are difficult to come by. This compounds the problem of assessing the health of a shark stock, as you don’t know how much there is to begin with. In addition there are virtually no regulations over the amount of sharks taken during fishing trips.
 

Finning

Shark finning is one of the most barbaric fishing practices that occurs in the industry today, sharks are caught predominantly on fishing ‘long lines’ that dangle many thousands of hooks over a huge area and catch a wide variety of marine creatures such as turtles, billfish and sharks. Once caught, the shark has its fins cut off and the less valuable carcass disposed of, the shark’s finless body, known as ‘logs’, are thrown overboard and the often still-living shark slowly suffocates. Sharks fins are used almost exclusively in the creation of an Asian delicacy known as sharks fin soup, a soup in which the fin adds no particular flavour and serves more as a thickening agent to add consistency.

When offered, the soup is seen as a symbol of prestige particularly in Asia, corporations for example will actively provide the soup during business events so as not to seem disrespectful to potential clients. The soup gained this ‘prestigious’ status during the Ming Dynasty and was originally served as part of the formal banquets that were hosted by the emperor. This delicacy is a dish that has been singled out for the affluent and commands a price of 100 USD. Originally purely by expense it was out of reach for the masses, however with an increasingly affluent emerging middle class of China, the economic drive and incentive to provide fins for sharks fin soup are expanding.

This demand has enabled fishers to expressly kill sharks that they may have otherwise released; commercial fishing vessels will target tuna or similar value fish, but dramatically increase their revenue by harvesting sharks fins. Sharks fins take up much less space than then the tuna flesh and are dried and stored typically on deck so the more valuable tuna can be preserved in the hold. This method of fishing is economically appealing to the fishermen who are able to double their revenue for a fishing trip, and has the added effect of a dramatic increase in fishing effort as the tuna fleets are already so well developed. A further problem is that once the fins are removed and dried (a process that occurs at sea) they become extremely hard to identify to species level. This means that endangered species of sharks may be caught, finned and then relabelled as another species for import purposes. Many endangered sharks such as the Great White Shark are still caught and finned without fear of penalty.

The cumulative effect of this action is that global populations of sharks are being increasingly heavily fished. Sharks have an extremely low reproductive rate that makes them more vulnerable to exploitation pressure than most fish. Although population numbers for sharks are uncertain at best with many of the IUCN Red List species (the world's most comprehensive inventory of the global conservation status of plant and animal species) listed as ‘data deficient’. Trends in global shark populations illustrate a precipitous decline in populations over the last 20 years driven largely due to finning.

According to the IUCN Shark Specialist Group, the easiest way to prevent finning is to implement a ban to require that shark carcasses be landed with fins attached. The possession of fins alone on vessels would thus be illegal and reduce specific finning. However the need for cultural education, especially in geographies where sharks fin soup is so popular is dire. Public attempts to counter this cultural stigma have been made, for example when NBA star Yao Ming announced publicly that he would stop eating sharks fin soup under any circumstances. The expected media frenzy was snubbed in China with Ming receiving a reproach from seafood industry associations for making rash remarks that affected the livelihood of the global fishery, seafood and catering industries.

The basic truth is that sharks are being seriously overexploited worldwide, and the predominant economic driving force for this overexploitation is for their fins. Sharks with such a low reproductive rate are unable to replenish populations with so many sharks killed daily. It is vital, fisheries managers meet to introduce quotas and reductions in catches for the targeted species, as well as introducing legislation to reduce specific finning. Although it is difficult to get international agreement or legislation on the management of these animals, due to their oceanic nature, if the process is delayed too long then sharks maybe fished into a state where there are literally two few of them to be able to effectively reproduce and they will slip towards extinction without any help from humans. The only answer may be similar moratorium to that which was placed on the great whales is brought about or the sharks will become one of the first great global ocean fisheries to become extinct.

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History of Shark Fisheries.

Shark products have been used throughout history with every part of their anatomy being used for some purpose (Walker, 1998). The regular occurrence of Spiny Dogfish (Squalus acanthias) spines within Native American sites in British Columbia dates back 5000 years (Walker 1998)

The first targeted fishery for sharks that was undertaken on a commercial scale occurred during the 2nd World War. Fishing for Cod Liver oil, a substance rich in vitamin ‘A’ collapsed when it became too dangerous to fish in European waters and the North Atlantic. As a result fisheries in California blossomed fishing principally Soupfin shark that supplied much of this demand from their livers. This fishery collapsed however in the 1950’s when synthetic alternatives were found.

In the early 1980’s exploitation increased again for sharks. The Chinese market downgraded sharks fin as a luxury commodity and this with a reduction on the tariffs of imported fins saw the domestic consumption skyrocket. In other areas declining fisheries of more traditional catches led to shark meat being seen as a cheap source of protein. By the mid 1990’s the price for dry shark fins had reached US $60 per kilogram (Castro et al, 1999). This led to the economic incentive to harvest sharks purely for their fins and the true explosion of the finning culture.

Currently shark fisheries occur the world over and catch most large species of coastal and oceanic sharks. The fin trade has made itself known right down to rural artisanal fisheries who are well aware that to catch a shark means a valuable prize. According to a recent paper in the journal October 2006 edition of Ecology Letters, the world fin trade may be responsible for 73 million sharks, a figure 3 times higher than reported by the United Nations.

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The Great By catch Swindle

The dolphin safe label originated in the late 1980’s when tuna-canning firms boycotted tuna harvested on dolphin sets. Reacting to high dolphin mortality rates and public outcry, Congress formalized the consumer label for “dolphin safe” tuna in 1990, a measure that was initially enforceable through trade mechanisms.

The definition of “dolphin safe” has changed significantly since then. Today, under the Dolphin Protection Consumer Information Act, dolphin safe tuna allows dolphins to be encircled and accepts a certain number of dolphin mortalities per vessel set. Once a vessel’s dolphin mortality quota is reached, vessels are no longer allowed to set purse seines over dolphins.

As a result of the dolphin safe label, the tuna fishing industry has modified production methods to meet consumer demands. Increasingly more fishing effort and sets are geared towards floating devices, or log sets, instead of dolphin sets.

It is now estimated that no more than 2500 dolphins are killed each year in purse seine sets on tuna. Dolphin populations appear to be recovering at a rate of about 2% per year. But there has been a trade off; focusing more effort on log sets has increased the by catch rates of other species such as Mahi Mahi, sharks, and Wahoo.

Although log sets reduce dolphin by catch, the discard rates of tunas caught in log sets that were too small or too damaged to sell are about 15 times higher than those from dolphin sets. Furthermore, the total biomass and diversity of by catch increases dramatically.  Examples of by catch include Mahi Mahi and Wahoo. Of particular concern are sharks, rays, and endangered sea turtles, because like dolphins, their population growth rates are low.  This type of by catch has the potential to severely reduce biodiversity levels.

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Shark Fishing for Sport.

Shark fishing contests seriously took off around 30 years ago; they are a contest born of fear and morbid fascination for a creature that is supposed to be deadly to all humans. It is no surprise that the release of ‘Jaws’ a film about a killer shark swept the box office. It created a culture of fear so intense that scuba diving with sharks was seen as an extreme sport due to the ‘shark menace’ that existed towards anyone daring to put a foot in the water.

Sharks became popular for their heads, and prized as trophies, their jaws and teeth can still be found in the markets the world over today as curios.

In addition shark-fishing tournaments such as the Oak Bluffs Monster Shark Tournament, based in Martha’s Vineyard (incidentally where jaws was first filmed) have developed into annual events. These shark killing melee has an enormous first prize of $130,000 for the largest shark caught creating incentives for the mass culling of sharks from around these waters.

Some of the species that contestants enter into the competition are listed by the IUCN Red List such as the Porbeagle Shark (Lamna nasus) a species listed as endangered by Canada after declining populations for the past 50 years. The sharks range includes bothe Martha’s Vineyard and the Canadian waters meaning that the contestants are almost certainly fishing for an endangered population of shark.

In addition the tournament organisers often try to dress up the killing via scientific research saying that examinations of the caught sharks help to advance the understanding of the species. However while there is scientific merit in examining dead specimens its hard to justify the mass killing. Especially when only the larger more fecund species are targeted providing questionable information that won’t be considered as standard when described for the species.

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