The state of Western Australia is using some of the same technology that shark researchers are using in Hawaii, except they’re going a step further to warn beachgoers of individual sharks in near-real time on Twitter.
Western Australia, which is reeling from six fatal shark attacks in two years, has tagged 340 sharks with acoustic transmitters that trigger the Twitter alerts whenever they get within a half-mile of popular beaches, most of them near the state’s largest city, Perth.
The new warning system costs $900,000 a year to maintain and employs receivers on buoys that send signals to a satellite before transmitting information about shark size, breed and location to a shore-based computer that immediately sends out the tweets.
Chris Peck, operations manager of Surf Life Saving Western Australia, said the warning system does a far better job of alerting the public than traditional warnings.
"Now it’s instant information," he told Sky News, "and really people don’t have an excuse to say, ‘We’re not getting the information.’"
In Hawaii, University of Hawaii researchers are attaching both acoustic and satellite transmitters to tiger sharks in an effort to track movements as part of an ongoing study to learn about behavior. The state last year gave $186,000 to the project following a rash of shark attacks off Maui.
Although the satellite tracking data is being posted on the Pacific Islands Ocean Observing System Hawaii Tiger Shark Tracking website at pacioos.org/ projects/sharks, the site cautions that it does not provide real-time monitoring and is not intended as a warning system. In fact, it says, there could be more than a mile in error associated with the tracking.
Bob Endreson, a retired commercial fisherman and founder of the Hawaii Fishing Foundation, said the state simply isn’t doing enough to warn residents and tourists about the potential danger of sharks, especially considering the two fatalities last year and 24 shark attacks over two years.
"The state does not think out of the box," Endreson said. "With all the negative publicity the attacks generate, why wouldn’t the state do everything it possibly can if the technology is proven to work?"
Endreson, who helped write the state’s legislation banning shark finning, said that while it’s important to know what’s going on with the species over time, the safety of our beaches is paramount. "Don’t tell me where they’ve been, thank you very much," he said. "Tell me where they are right now."
But Kim Holland, one of the UH researchers contracted by the state, said a warning system like Western Australia’s would not be particularly useful in Hawaii. He said it’s impossible to tag every shark in the ocean and that any warning system would end up conveying a false sense of security to beachgoers.
"We know tiger sharks are in our waters 365 days of the year and there are lots of them but only a few attacks a year," Holland said.
What’s more, tigers aren’t as dangerous as great white sharks, he said. Great whites are rare in Hawaii but common in Australia.
"Whites make a living attacking large warmblooded mammals, and tiger sharks feed on fish, invertebrates, octopuses and more."
The warning system, he said, is likely quite expensive.
"It’s a complicated situation," Holland said. "There’s always some pressure on the government to do something, but it’s not always feasible. Sometimes you just have to say, ‘Sorry, we can’t do that.’ We can do a better job scientifically by learning about what’s happening over the long range."
Western Australia’s shark monitoring system includes 24 satellite-linked receivers, plus nearly 300 other acoustic receivers on the ocean floor. Researchers have so far tagged 141 white sharks, 23 tiger sharks and 176 large whaler sharks.
It’s part of a $20.5 million effort that includes money through 2015 for research, monitoring, operational activities, aerial surveillance, beach enclosures and public education, said Ashley Malone, spokeswoman for Western Australia’s Department of Fisheries.
Research projects currently being funded include studies to independently test and improve existing shark deterrent devices; to develop and test novel deterrents such as bubble curtains, underwater sounds and strobe lights; to research sonar imaging and detection of sharks; and to develop computer algorithms for real-time, automatic shark detection.
Funding has also been made available to develop a surfboard skeg with an in-built electronic shark deterrent; to develop systems that mask noises of beachgoers (including swimmers and surfers) that attract sharks; to develop an acoustic system to detect sharks as they approach beaches; and to define the visual, electrical and vibrational (sensory) cues that trigger shark attacks to help in developing shark deterrents based on knowledge of what causes shark attacks.
However, for all of this potentially meaningful research, it has being overshadowed by another part of the initiative: a shark-culling program employing drum lines in the ocean off popular beaches. Sixty-six sharks have been caught in the baited aquatic traps since the program was launched last month, 17 of which were killed and nine others found dead in the traps, Malone said.
While government officials have described the program as successful so far, thousands of Australians have joined protests, calling it inhumane, and international experts have condemned it as futile.
Hawaii officials have declined to hunt sharks following attacks, saying shark incidents do not decrease in the wake of a hunt, since the late 1950s. In addition, research has shown that the tiger shark is not territorial, but roams far and wide. So, the culprit is unlikely to camp out, stalking the coast where an attack occurred.
