First, shark bites are discrete, random events—but they look like intent-based incidents. Shark bites are random, independent events: the likelihood of a shark attack happening somewhere does not depend on where/when the last one occurred.
“[Shark bites] can seem to occur in clusters… but the likelihood of any one individual being attacked by a shark at a given time and place and the average interval between any two attacks remains constant,” late shark biologist Aiden Martin once wrote.
However, the odds of having a shark bite incident be followed by nothing for a long extended time are relatively equal as having a cluster occur. When a cluster does happen, one should look for new factors that may have popped up. Take the Florida 2001 shark bites. Why did no one check ocean currents and ocean temperature? What about food supply? Or water chemistry? Do these things not affect animals?
Third, we only count when human-shark interactions occur, not when they don’t. That is, to remember that there are thousands of times when humans and sharks share the same habitat and bites do not occur—including months when sharks migrate in their highest numbers along the coast.
Since 1580, there have been only 153 human fatalities attributed to all species of sharks combined worldwide, yet nobody ever puts that as a disclaimer while writing up a piece about these “man-hunting predators.” If shark encounters were portrayed with less dramatics and more science, these random events would not be so terrifying.
The Western Australia Cull
In WA, many are calling for the government to stop and pursue alternatives (i.e. EcoSharkBarrier), as there is no evidence that shark culls reduce the risk of attack. In fact, when the Hawaiin shark cull (1959 to 1976) killed over 4,500 sharks, yet there was no reported significant decrease in the number of shark bites recorded.
These valid scientific considerations are not being taken into account during the implementation of this cull. WA’s Environmental Protection Authority (EPA) previously ruled out assessing the trial of the shark cull, which began in January and is set to end the end of April 2014, claiming that it posed a negligible risk to shark species. EPA deemed the cull to be of “very limited duration… [and] will not have a significant impact on the environment.” However, the EPA is now reviewing the resuming of the cull on 15 November 2014 until the end of April 2017, where the program is put under review. The extended shark cull will see 72 more baited drumlines, set at approximately 1 km (0.62 miles) offshore of popular beaches and surfing spots within two Marine Monitored Areas (MMAs) – the Metropolitan MMA (Ocean Reef to Port Beach) and the South West MMA (Quindalup to Prevelly).
While this is the “only way” seen by the government to prevent shark attacks, a survey of 583 people visiting Sea Life Sydney Aquarium found that 77% of the respondents were "not at all frightened" or only "moderately frightened" by sharks. And 87% said the animals should not be killed. The survey, released by the Sea Life Conservation Fund, was answered by a wide range of ages: from age five to 75. It found 69% of in favor of public education as the best method in preventing attacks, and 18% said to leave the sharks alone.
There have been 892 shark attacks on people off Australia since records began in 1791, 217 of which were fatal. In 2013, two human deaths and 10 “attacks” were reported for Australia, according to the University of Florida's annual International Shark Attack File. Of the 583 surveyed, 4% supported shark hunts, and 9% advocated more shark nets (as a barrier or to catch sharks was not made clear).
Ordinarily, it would have been illegal to carry out such a cull, but in this case it was able to proceed as Federal Environment Minister Greg Hunt granted the WA Government an exemption from the Environmental Protection and Biodiversity Conservation Act, stating that the cull was for the nation’s interest.
However this exemption does not retract from the fact that great white sharks are protected under WA and Australian environmental laws, not to mention several international agreements including the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) and the Convention on the Conservation of Migratory Species of Wild Animals (CMS; also known as the Bonn Convention). The great white shark is currently considered as Vulnerable on the IUCN Red List of Threatened Species, listed on Appendix II of CITES, Annex I of UN Convention on the Law of the Sea (UNCLOS), and Appendix I and II of CMS.
While great white sharks are the main target of the policy, the shark’s peak season is June-August in WA, outside of the current (and proposed) operational drumline time. The proposed period is November to April (see page 13 of DoF report). The problem with drumlines are that they are indiscriminant and will catch/kill other species including, but not limited to dolphins, turtles and other non-shark species. Although the WA government guaranteed that hooks were designed for sharks 3 meters or bigger, 75% of the total catch during the first few weeks were undersized tiger sharks; all were released. Photos and video taken by activists show that many of the freed animals were still dying.
“As many as 70 percent of released undersized sharks sink to the bottom after they’re released,” says Riley Elliott, a PhD student at the University of Auckland in New Zealand who has been observing the cull.
This loss (post-release mortality) is common in catch-and-release fishing as well as commercial bycatch. “The physiological stress and injury from capture can be lethal, either outright or in the hours and days subsequent to the capture event,” says John Mandelman, director of research at the New England Aquarium. “Thus, even a fish discarded in seemingly good condition that swims away may still die once back in ocean.” In the case of the cull some of the post-release mortality stems from sharks being immobilized by the hook for long periods of time (sometimes overnight), being preyed upon by larger sharks or capture stress and mishandling from fishermen. Studies focusing on capture stress and post-release mortality have noted tiger shark fatalities being extremely low if the fish are handled properly. The sharks are left for long periods of time, exhausting themselves as they try to escape, and their body’s initial response raises acid levels in tissues and may disrupt biological processes in the shark.
Today, June 17th, 2014 the WA government has approved the controversial cull’s expansion of three years.
Why is this money not being spent on research or education? EDUCATION IS ESSENTIAL. Why is it being geared towards something that is not catching the ‘target species’?
Fisheries opposition, Dave Kelly agrees.
"Every (fatal) shark attack in WA in the last 10 years is believed to be ... from a great white shark. Even on that basic measure this policy has been a failure.You can't say you're responding to the spate of fatal shark attacks seen here in WA if you're not catching the shark everybody believes is responsible."
The Environmental Protection Authority is accepting public feedback until July 7. IT HAS NOT YET BEEN APPROVED 100%, BUT IT SEEMS LIKE THIS WILL GO THROUGH.