In case you missed it. In a remarkable win for common sense, the proposed full implementation of the WA shark cull has been shelved by the EPA (Environmental Protection Authority). Their stance can be seen in the following statement by the regulators chairman Paul Vogel .
At this stage, the available information and evidence does not provide the EPA with a high level of confidence. In view of these uncertainties, the EPA has adopted a cautious approach by recommending against the proposal
So what could possibly make the EPA that uncomfortable to recommend against the WA government?
To understand, we need to look back at the trial cull.
In January the WA government controversially introduced a 13 week trial period where baited drum lines were set off Perth and South West beaches. This was in direct response to an increasing trend of shark attacks over the last five years culminating in the death of Chris Boyd off Gracetown. All of these attacks have been attributed to the Great White Shark.
For the trial, 72 baited drum lines were deployed in two zones, one off Perth and the other in the states south. Bull, tiger and great white shark species measuring over 3m would then be destroyed.
The logic being, less dangerous sharks in the water would equate to less attacks.
The cull by numbers
The WA government called this a successful trial and applied to extend the cull for a further 3 years. Was it really a success?
From a catch point of view, the effectiveness of the cull was 28% with a collateral damage of 10%. Meaning 1 in 3.5 animals caught and destroyed were meant to be, while 1 in 10 were not. Numbers also don’t take into account how many “released” animals actually survived the injuries sustained in the process.
A 2.7m Tiger Shark sinks to the bottom after being released "Alive". Photo A. Corbe
From the view of human lives saved, it was a raging success. In a Dilbert world pie chart, 100% humans saved, 0% not saved.
So 28% success rate in catching = 100% human lives saved. Looks very successful. Imagine if we could increase the catch effectiveness – we could save even more human lives!
But hang on, wasn’t it less dangerous sharks in the water would equate to less attacks? And wasn’t it the Great White responsible for the attacks?
Except none were caught..
So somehow 0% caught=100% saved but … doesn’t that mean not catching these sharks is as effective as catching them?
You can now understand how the EPA would be nervous endorsing this sort of reasoning.
It simply didn’t add up.
|Has spent over 30 years of his middle aged life trying to spend more time in the ocean. Likes to surf, bodysurf, free dive and pretend he enjoys chasing big waves.|