Shark attack data

 While I was bored a little while ago I put these graphs together.  They are based on recorded all recorded shark attacks in WA.  There are two graphs - one for all shark attacks, and one for fatal attacks.  Notes on reading the graphs:

1.  The green line is total population, read off the left side axis.

2.  The yellow bars are the number of attacks in each year, read against the right side axis.

3.  The blue line is the rate of attacks in that particular year, calculated as number of attacks per million population, read against the right side axis.  This is meant to normalise for population growth.

4.  The red line is the 10 year moving average of the blue line, read against the right side axis.

5.  This data does not have any species information.

6.  The fatal attacks are a subset of the total attacks i.e. the total attacks includes fatal attacks.

 

A couple of things that they point out to me:

- historically, the rate of total attacks is fairly consistent, although we appear to be in an upswing, but not significantly higher than past peaks.

- there has been a large increase in fatal attacks since the early nineties.

 

**UPDATE - added marker on graphs to show when GWS were protected in the late '90's.***

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so in a nut shell based on

Tue, 2018-04-17 13:22

so in a nut shell based on your graphs since the GWS was protected circa 1999/2000 the rate of attacks has been steadily increasing.

Daryn's picture

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 I am not sure the

Tue, 2018-04-17 13:54

 I am not sure the correlation between population and attacks should be considered in a linear fashion. If a hungry white comes along and there are 100 times more people, it can still only eat one of them. 

 

Yes, there may be people in the water in places they never were, but this explains a small increase, not the large one we see now.

 

 

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Possibly

Tue, 2018-04-17 14:45

I don't have any insight as to the reasons why the increase. 

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IncognitOh's picture

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But.......

Wed, 2018-05-02 19:50

 If there are also 100 times more sharks in that same water..........

Auslobster's picture

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Percentages....

Tue, 2018-04-17 18:41

 ...in 90 years, the WA population has increased 5X (500%). But what is the percentage increase of WATER USERS? I'm guessing, over that 90 year period, it's way more.

 

Surfing was invented in the early 1900s by the Hawaiians...and didn't become mainstream around the world (and WA) for many years. SCUBA diving wasn't invented until the 50s, and I doubt the average Joe Bloggs was doing that with any frequency until at least the 60s/70s. Probably safe to assume that snorkeling wasn't hugely popular until later in the century, too.

 

Point is, yes more people in WA, but of those people, an even higher number entering/using the ocean than even just 30/40 years ago.

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Good point

Tue, 2018-04-17 19:19

I’d also bet more people diving for crays and spear fishing.

 

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sea-kem's picture

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 I saw it through the early

Tue, 2018-04-17 19:32

 I saw it through the early 90's where SCUBA became more affordable for the average punter and dive shops were popping up everywhere. In my class where two Japs who couldn't even swim lol. 

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 It's a numbers game or so i

Wed, 2018-04-18 16:43

 It's a numbers game or so i thought until I read that acting fisheries head honcho mr cook say that drumlines were a indescriminate way of killing sharks to make the public think there are less sharks in the water. excuse me but i thought if you kill one shark then yes there is one less and the only way to reduce shark attacks is to reduce the number of sharks if there is a attack and more than one shark is take from the area i would call that a bonus 

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Whales and seal numbers

Wed, 2018-04-18 18:22

Add humpback whale and seal numbers to the graph and see what that brings.

 

As someone who has spent years at sea and one notices the huge increase of whale numbers heading up and down the coast since they stopped commercial whaling to what they are now plus the growth in seal numbers in the same period. One example is the colony on Cape Naturaliste, go back 15 years and there wasn't a colony there yet a mate told me not long back that he has seen up to 40-50 there on good days.

 

Allright a whale carcass washes up on a beach and the media say it attracts sharks to the area, well bugger me dead, how long has it been floating out there attracting them. The media are the main cause of all the histeria from these attacks. Go back to when Ken Cruse? got his leg bitten off at Cottesloe beach, we had Rory Mc Cauley from Fisheries shark research on board at sea out of Port Hedland and when we heard of the attack he was dreading coming in to phone range because of all the media attention that he was going to receive.

Auslobster's picture

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So basically...

Wed, 2018-04-18 20:49

 ...if there are more people in the water, and more prey (whales), and attacks increase, the solution is to kill more sharks?

gillyL's picture

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 Great whites dinning out on

Sat, 2018-04-21 10:12

 Great whites dinning out on dhu's and baldies hahaha. 

 Seriously though im just here for the peter mac tiger shark story

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lucky i love to fish because i cant catch any.

 

BM294

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 Just getting back to the

Sat, 2018-04-21 10:46

 Just getting back to the original post.

id be interested in the data from when the Shark fishery was stopped in metro waters. I was talking to old shark fisherman many years ago and he said although he didn't target them he would quite often get Great Whites in his net or if not stuck seen where they had ripped a hole in the net and possibly gone away and died due to the net.

 

I acknowledge that he also said that the majority of his income came from "Scale  fish" bi-catch

 

 

 

Gunner

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Whites....food

Sat, 2018-04-21 11:15

 I thought when they reach a certain size 

there main diet is mammals... seals and 

so on ...and they have there own built in 

gps return too certain areas over and over

each season.. hang just wrote a post 

without calling anyone a c@:t .. lol

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Modded

Sat, 2018-04-21 11:22

 No need for the troll

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Da pirate's picture

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Fair call ..

Sat, 2018-04-21 11:32

 fair call Adam.. apologies..

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Not you mate

Sat, 2018-04-21 11:34

 Not you mate, the other numbnuts that is now banned.

Cheers

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Sat, 2018-04-21 12:13

 

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 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.

 

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Good doogs

Sat, 2018-04-21 11:38

 

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all aggressive fish love bigjohnsjigs

Rob H's picture

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 Pretty sure he will read

Sat, 2018-04-21 14:31

 Pretty sure he will read this.

His loss if he realises what a great resource FW is, with longstanding members willing to help newcomers alike at the drop of a hat despite different views on subjects like this.

Hell only the other day when I enquired about some items on here I got 2 unsolicited messages from members saying theyre coming up my way and could bring them up if needed.

How good is that?

Everyone has a bad day now and then, but best avoid ya first posts on here if they coincide with a bad hair day.

Didnt Til drop off here a few years back over a similar subject?

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 Give a man a mask, and he'll show you his true face...

 

 

The older you get the more you realize that no one has a f++king clue what they're doing.

Everyone's just winging it.

 

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 Yep, he got fed up with the 

Sat, 2018-04-21 15:17

 Yep, he got fed up with the  trolling. A bloke with a wealth of knowledge, he even came over to my workshop to give me some pointers on my boat rebuild. 

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