As I am sure you are all aware by now (unless you have been living in a naive little cave for the past 10 years , for which this next statement might be quite shocking to you..) the state of the worlds sharks population is screwed! Greedy fishing nations are harvesting the oceans of its sharks, millions of fins at a time. Many of the worlds shark populations have seen huge declines (up to 99% in some species), which has been largely attributed to fishing activities. Although the scientific, public and political world are slowly coming to grips with the unhealthy state of the oceans, is it too late to “save the sharks”? A new review from Dalhousie University, Canada suggests not.
Years of over exploitation and very little protection has lead to huge declines in shark populations. The declines have often been attributed to anthropogenic operations such as overfishing, fisheries by-catch, pollution and habitat destruction. Sharks play a pivotal role within marine environments and are essential for the healthy function of ocean ecosystems. Despite this knowledge, tens of millions of sharks are still being killed every year; millions of year of evolution and dodging global mass extinctions only to end up with part of you body in a soup bowl.
Recently, however, the true value of live sharks within an ecosystem and tourism is slowly being realised. This is reflected in the slowly emerging conservation and management programs, although it is still unclear if any of this practices are actually working. Christine Ward-Paige (lead author) and others attempt to evaluate the success of some of these practices on the the recovery potential of elasmobranch (sharks, rays and chimeras) populations.
By compiling information from scientific literature from shark populations that have demonstrated an apparent increase in abundance, the authors highlight and discuss the success of current conservation tools (listed below).
Restricting fishing mortalities:
Practices such as seasonal closures of fishing zones, quotas and gear restrictions have been implemented within certain fisheries. Evidence suggests that the increases in scalloped hammerhead (Sphyrna lewini) and reef associated sharks within the Bahamas could largely be due to changes in fishing practices. Although these results look promising, the majority of fisheries are still to develop and adopt proper protection policies.
Shark Finning Prohibitions:
The contrasting price difference between shark meat and shark fin has lead to the development of finning practices. Sharks are often harvested solely for their fins, whilst the carcass is often discarded over the side in order to not fill up the boat with worthless meat. Shark finning prohibitions have existed for more that 30 years now and are increasing momentum as a conservation tool. With an increase in restrictions and trading policies there is a need for increased enforcement and fines in order to effectively reduce population mortality rates.
Bahamas, EEZ of Palau, Maldives, Honduras, RRA of Indonesia and Marshall Islands have all recently established shark sanctuaries. These shark safe havens can cover huge areas of ocean, but need to be properly managed and monitored. Although it is too soon to identify how successful these areas are at rebuilding shark populations, looking at other non shark specific MPA’s already indicates that even small areas can be hugely effective at increasing shark numbers. The protection of highly migratory shark species is difficult using this approach, but the protection of nursery and breeding grounds would be ideal.
Environmental factors such as water temperature and ocean circulations can influence the behaviour, distributions and prey availability of sharks. As nursery zones are often associated with coastal waters that just so happen to be very attractive to humans for building massive holiday resorts and obnoxious golf course, the destruction of these crucial habitats is not uncommon. Evidence suggests that habitat restoration can improve the feeding and growth for certain shark species, and for other species, restoration programs could have in fact stopped the extinction of such sharks.
Species Specific Conservation:
This can be adopted when certain species are at the highest risk of extinction. This is often hard to enforce, as the fishermen responsible for their demise often mis identify target species. So little is known about the life history, distribution, behaviour and population dynamics of target sharks, it is hard to design conservational plans that will work. How do you protect something that you don’t know where it spends its time feeding, breeding and migrating? Even if a species is “protected”, it does not stop the incidental mortalities linked with fishing by-catch or shark protection devices.
Call me an optimist, but in recent decades I strongly believe that the public perception of sharks has improved. Although shark week occurs annually on the discovery channel, I can still usually find a health dose of shark based programs over the internet and TV. Coupled with an increase public desire to see these animals in the wild, education shark dives can be a great incentive to protect local shark populations. If the global perception of shark based products, such as shark fin soup, can be altered, it would be invaluable to the future of shark populations.
It is demonstrated that even low exploitation rates (2-6% per year) is enough to prevent recovery or even reverse the positive increases in shark populations. Management measures that are currently being implemented are showing promising results in protecting shark populations, but they can all be negated if conservation schemes are not continued or effectively managed. Although it may still be too early to assess the full extent of how effective current measures are in protecting sharks, its beginning to look better for sharks. I’d strongly recommend viewing this paper. Really easy reading, filled with useful references and is a nice summary of the current state of shark conservation.
Source: Ward-Paige, C., Keith, D., Worm, B. & Lotze, H. (2012) Recovery potential and conservation options for elasmobranchs. Journal of Fish Biology. 80. 1844-1869