How do they find the shark responsible for an attack?

[seekinglondonlife]

Just read the sad story about the British man killed in a shark attack in Australia.
According to the BBC News, lifeguards have been jetskiing and aircraft travelling 25 km to find the shark, which will then be culled. How on earth do they find the responsible one? According to the site, they usually do within a few days. And why do they kill it? Would it be more likely to kill again?

@TankFlyBoss

I think it's because it now has a taste for human blood

It’s a shark, not a vampire.

@BananaSpanner
That was a really enjoyable and informative post. Thanks.

I didn’t realise it had been so long since last fatal attack in Sydney

@Fireblanket no they won't, what a ridiculous thing to say. It's 6am here and the beach is busy and full of swimmers.

I haven't taken anything you've said as argumentative, it's all good. I like a respectful debate. And I find this all truly fascinating.

So yes you're right, taste and sight both play a role. Shark looks for rough shape of seal based on it's experiences so far, usually starts by taking an exploratory bite as this doesn't expend massive amounts of energy. If it tastes like meat and blood, all good, goes into full attack mode and adds that modified image to the database if it's not quite the thing it was expecting, shark now has a wider repertoire of things to hunt and is at an evolutionary advantage. If it turns out to taste like surfboard or plastic or something, again it's got useful data for it's database that that particular shaped object, despite faintly resembling a seal, in fact isn't edible. So their search images get more accurate over time as they discount things that look similar but have slightly different distinguishing characteristics.

In terms of how that relates to my original point about it not being about developing a taste for blood, I guess what I'm trying to say is it's not about the shark actively seeking out more humans because it's favouring the taste of them, and more that it simply expands its repertoire of known edible objects to include human shaped objects which therefore increases the risk to anything else in the ocean that resembles a human shape. But I didn't articulate that particularly well, so yes, it is partly about taste.

@Thatsplentyjack

Poor guy. What an awful way to die, and the poor guy that witnessed it! There's just no way I would get in the water in Australia. I live in Scotland and wouldn't go in the water here. I remember going to Spain when I was 15 and being absolutely terrified in the water. I spent the whole time looking down to see underneath me. It's not like it's a complete shock that there are sharks I the water in Australia.

Shark attacks are pretty rare here in Australia. The last deadly attack in Sydney was in 1963 and besides if you were swimming in the ocean you'd be given warning to get out long long before the shark reaches the shore as the shark alarm will go off giving everyone plenty of time to get out. When attacks happen it's usually at a location where there are no shark nets, on un-patrolled beaches (like this situation) or in an area that's likely to attract them such as where rock fishermen are as the bait can attract them.

Shark culling isn't really a thing here unless the shark will be a further danger to humans but usually if they're caught they're tagged and then released in another area. Us Aussies know that when we're in the ocean we're guests in their home which is why from a young age we're taught about what to do just in case. Swim between the flags, if a beach isn't patrolled think twice about swimming there, don't swim after dusk, if the shark alarm goes off (doesn't happen often) get out of the water. When people call for culling it's usually an emotive response as those same people will be out there swimming on the next 40 degree day.

How would you relocate a shark of this size?

@seekinglondonlife

How would you relocate a shark of this size?

Not sure, smaller shark species would be easier as they can just stun them before putting them on the boat but a great white would be a lot more difficult so I would assume they would find it and then tag it. The CSIRO has some information on tagging.

www.csiro.au/en/research/animals/marine-life/Sharks/Tagging-white-sharks

@Ionlydomassiveones

“Being a pedant, we don't actually know he was eaten. He was certainly very bitten, but unless the shark is opened up, no one can tell if he was eaten. Parts of the body can be lost to sea or eaten by other ocean creatures.”

There were eye witness reports according to the paper.

There's a video if you really want to know. I haven't watched it, wouldn't want to. Someone videoed the whole attack and yes, multiple eye witnesses. Awful for everyone. But agree, shark shouldn't be killed.

@MichaelAndEagle DS is in Bondi and has seen the video. He said he won't send it to anyone else - absolutely horrific, and shocked everyone.