Sharks have been around for a very long time. They´ve been roaming our oceans for over 400 Million years – an incredible time span and way ahead the first appearance of dinosaurs 230 million years ago. Over time they have evolved to perfectly adapted predators in a very diverse group: the whale shark may reach up to 16m whereas the dwarflantern shark only reaches about 20cm. Some speciesmen like the basking shark and whale shark are huge, yet they feed on some of the tiniest organism in the ocean – plankton. Others roam the deep oceans in up to 3700m depth or have become specialists like the like the greenland shark, that even populates the arctic oceans.
Many of the more than 440 described shark species tend to live long and grow and reproduce slowly. Sharks belong to the so-called K-strategists (like we humans too), meaning they produce little offspring and live longer in comparison to r-strategists (producing large quantities of offspring and short life spans, e.g. mice). Additionall, most sharks take a long time to sexually mature (up to 20 years !) and may have very long gestation periods. The spiny dogfish, a small and widely distributed shark, even tops elephants (with app. 22 months) with an incredible 24 months gestation period. Sharks have adapted perfectly to their environment and evolved as a successful group of animals until humans populated planet earth and brought misbalance and disaster to many equilibria that existed for million of years.
Sharks have been caught and utilized for a very long time, but their meat was regarded as low value and the demand (and available fishing techniques) were too small to substantially impact the populations. The shark fishing industry underwent several booms in the early 20th century, for example in the 40s and 50s when the demand for shark liver oil exploded. The oil vontaining high amounts of vitamin A was (and is) used as a food supplement. Besides the liver oil, their cartilage is marketed as a health supplement and was long believed to help cure cancer. People thought and still think sharks cannot sicken on cancer, A myth which nowadays has been proven wrong with common sighting of sharks with tumors. Furthermore, shark skin can be used to produce leather and teeth as well as jaws have an ornamental value all around the world.
Nevertheless, that alone wouldn’t drive some species of this group towards distinction. It’s another product, that drives their sesytematic population decline: their FINS.
The demand for shark fins exhilarated in the early 1980 mainly driven by the chinese market. After the death of Mao Tse Tung, who discouraged the consumption of shark fin soup to keep it a luxury product only to be served china’s elite, this perception slowly changed. With many Asian economies booming during the 1980s and forming a new middle class, more people accquired enough wealth to be able to afford shark fin soup as a symbol of prestige and social status.
This increasing demand for fins throughout Asia has led to an enormous increase in shark fishing. Now sharks were worth a lot more money than before and were rather finned than released alive. Their meat is still of rather low value (with exceptions of high prized shakrs, like the Short fin mako) despite its consumption in virtually every country in the world. With many commercialy exploited food fish stocks decling and collapsing sharks are being reconsidered as potential moneymakers, offering protein and good sources of income. A study from Boris Worm and his colleagues in 2013 estimated that around 100 million sharks are being killed each year. This number by far exceeds the amount that shark populations are able to handle. They simply can’t produce enough offspring to equalize the take-out. The ruthless overexploitation in some parts of teh world due to non-existing shark fishing regulations have led to sharp declines in shark populations worldwide: numbers of Oceanic Whitetip Sharks and Silky Sharks in the Gulf of Mexico have dropped by 99% and 90%, respectively (Anon, 2007).
Since the most valuable parts of a shark are its fins, it’s common practice to slice them off and to dump the still living sharks back into the water (see video above). Without their fins they sink to the bottom and either bleed to death or suffocate due to the lack of movement. The bodies are being discarded to save space on board considering the fact that shark meat is simply not valuable enough to be kept and stored on the vessel. This way only 1-5% of the shark’s body weight is being used – an incredible brutal and wasteful practice at the same time. Almost the whole shark is simply discarded with all the valuable protein and a life is lost for a tasteless pair of fins to feed an acient tradition
Eventually the fins are dried and prepared to a soup that is served at important occasions like business banquets or weddings. It’s a sign of respect to the guests and displays the host’s wealth. Fins themselves are tasteless (!) and thus chicken or other broth is added to give the soup a taste. The huge demand of shark fins have made them one of the most valuable sea products worldwide with one bowl of soup selling for up to 100 Dollars! One kilo of dried shark fins can even sell for up to 1000 Dollars!
The question could arise, why sharks should be protected anyway? Well, there answer is actually quite simple. Sharks occupy many different trophic levels in the oceans, some being meso predators and others apex predators standing at the top of the food chain. If too many are removed, whole ecosystem can be altered and shifted. These so-called trophic cascades were studied by Myers and his colleagues in 2007, when they investigated the effect of a loss of apex predators at the East coast of the United States of America. The industrial fishery was responsible for a severe decline of bigger predators like bull sharks and tiger sharks, which in turn had fed on the cow nose rays in that area. The cow nose rays predated on scallops, which were also caught by local fisherman and represented a major source of income. As the sharks populations declined, the numbers of cownose rays exploded and reduced the scallops substantially. Eventually the scallop fishery collapsed in this area and many people lost their jobs. Everything is connected in the oceans and if we remove cornerstones like sharks it will have dramatic effects on many different levels.
Generally it can be said that sharks have a hard stand in the society. Since movies like “Jaws” the public perception of these magnificent animals is unfortunately a very bad one. A “Killer machine” how most people would probably agree, even though they´ve never seen them in the oceans. Due to their teeth and due to the fact that there have been fatal incidents with humans that entered their world people generally tend to dislike them or simply not care about them. If you compare them with dolphins, who always seem to smile – obviously most people associate a friendly animal which they´d like to protect. Many of us might have read the statistics comparing the shark caused death to the ones of falling coconuts, hippos and mosquitos. Sharks are only responsible for around ten deaths a year, an extremely low number if we take the millions of interactions into account all over the world. That’s the work conservation groups have to do and are doing: spread information, create a (bigger) lobby for sharks and increase public awareness for their protection.
There are almost no fishing bans on any shark species though things are moving. There are a couple of regulations that are supposed to help them recover. In the European Union sharks have to be landed whole making it a crime to land fins on their own. Though “special fishing permits” allow fins to be be cut off at sea and stored separately as long as the catch lies in the appropriate proportion. In the EU this fin-to-carcass ratio is set at 5%, meaning the fins can weigh up to five% of the sharks whole weight. The problem here is that this is impossible to measure on shore since the sharks are landed dressed, e.g. gutted and fins cut off. Even if it sounds good, the ratio needs to be adjusted. It is twice as high as as ratios used in other countries like Canada, where the dressed weight rather than the whole weight is used. This regulation therefore could lead to illegal finning by EU fisherman and still meeting the set ratio. In addition some sharks like the Blue shark have extremely large fins whereas others rather have small fins making the existing regulations extremely problematic. Instead of this 5% find-to-carcass ratio the EU should require all sharks to be landed whole.
In March 2013 conservation groups worldwide cheered when several species of sharks were listed on appendix II of CITES (International Trade in Endangered Species of Wild Fauna and Flora), a body that controls international trade of endangered and threatened species and this listing came into effect in Sep 2014. Until then only the White shark, Basking Shark and Whale shark were listed and finally five more were added. Appendix II strongly regulates the trade of products and member governments must prove its sustainability. A major step towards shark conservation.
Another organization aiming to protect sharks is The Convention for Migratory Species or CMS with 120 governments having signed the convention. Many sharks are highly migratory such as famous members like Whale shark, White shark, Hammerhead sharks or Silky sharks. In Nov 2014 the latter two as well as thresher sharks were listed on the CMS´ Appendix II which sends a strong signal that protection of these sharks is needed even though sustainable fishing is still allowed.
After several smaller Micronesian states have already declared their territorial waters as shark sanctuaries (Palau banned all forms of commercial fishing in its waters in 2009 and declared itself first shark sanctuary worldwide and the Republic of the Marshall Islands implemented a prohibition on the commercial fishing of sharks in 2011 in its water that cover almost 2 Million km2) the Federal States of Micronesia have just declared to create a nearly 3 Million km2 shark sanctuary in its Exclusive Economic Zone waters, that stretch out to 200nm from shore. Together with the protected waters of Palau, the Marshall Islands, Guam and Northern Marianas Island it forms the Micronesia regional Shark Sanctuary, a huge area covering an area lager than the European Union giving sharks a retreat area protected from (over-)fishing.
These nations have realized that a shark alive is worth way more money than a dead one and that not only their countries and the tourism strongly depend on the sharks living in the water but also the overall well being of the ocean. Many tourists including myself are willing to pay good money to see sharks during dive trips. Once they´re gone the tourism might drop too and with it a substantial amount of money that flows into the country. One alternative to shark fishing and finning might be sustainable shark tourism. In the Beqa Channel in Fiji a local dive operator has started to hand feed sharks several years ago. The number of attacks hasn’t increased like many people suspected at that time. The opposite is the case: local tribes grant their fishing ground to dive operators and earn money in exchange, letting the fish and shark populations thrive at the same time. Sustainable shark tourism will be playing a major role in the future.
The question remains if sharks could be harvested sustainably and whether this should be done. This is one of the questions that still needs to be addressed by many scientists all around the world. There are so many things about sharks that we don´t know yet – be it their behavior, their ecology, their mating grounds or reproduction cycle. It´s still a very long way to go but there are promising actions being taken by a great number of eager people around the world to improve the situation of sharks, understand them better and ultimately protect these delicate group to enable them to roam our oceans just like they´ve done the past 400 Million years.