subasurf said...

They are born at around 1.5m in size so they start off somewhat sizable but grow very slowly, which is the biggest concern we have.

There is so many different theories regarding age and growth rates of Whites around the net it's not funny. And realistically that's exactly what most of it is, pure theorising. It's about as useful as wetting your finger and sticking it out the car window to see if it's offshore on the way to the beach. Here's a selection of links in reference to Whites biology;
www.floridamuseum.ufl.edu/discover-fish/species-profiles/carcharodon-carcharias/
www.shark.ch/Database/Search/species.html?sh_id=1017
www.tigerhomes.org/animal/great-white-shark-taxonomy.cfm
underwater.com.au/article/id/7395-great-white-sharks-the-truth/
www.ccsa.asn.au/index.php?option=com_content&task=view&id=404&Itemid=594

Now THIS is the interesting one, of ALL the pfaff I've read on the net about Whites this is about the only real study with actual science and research published with it and the results were mind blowing for me. I had always swallowed the line about these things living forever and growing at a snails pace, well check this out.....www.publish.csiro.au/?act=view_file&file_id=MF10130.pdf Take note that this article is in reference to the Japanese population of Whites which is believed to be separate from our own.

This is a quote from the article referencing age of specimens examined;
Fig. 1. X-radiographs of (a) a whole centrum and (b-e) half of a corpus calcareum in the white
shark. (a, b) Male of 442.0 cm TL with 12 bands. (c) Female of 383.2 cm TL with 5 bands. (d) Male of
310.9 cm TL with 4 bands. (e) Male of 231.4 cm TL with 2 bands. Scale bars?10 mm.

So that's a male of 4.42m @12yrs, a female of 3.83m @ 5yrs, a male of 3.1m @4yrs and wait for it a male of 2.3m @ 2yrs. Now their growth rates may slow down once they hit 4m or so but until that get that big they are one hell of a fast growing apex predator. Also downright lethal from about 3m and really there's not much swimming around out there that's gonna phuck with even an 8ft White, so they're pretty much the local bully by the end of their second year of life.

Now by no means am I proposing or endorsing a general cull but I really do think we need some more concrete evidence of the biology of the species and that should entail taking a cross section of the local population and studying them.
A 5m, 4m, 3m, 2m of both male and female specimens and check 'em out, it's only eight sharks out of the population but it would give us a real idea of growth rates etc.

As to the recent spate of attacks here I think it's an anomaly. I think the death at Bonies was our statistical norm for the year and more fit the pattern that we traditionally see of bloody big Whites (5m+) making a meal of someone.

The others were more unusal, all were witnessed, other than Bryn Martin at Cott and all were estimated to be a 10-12ft shark. Even the shark suspected of taking Martin was estimated at 10-12ft judging by what was left of his bathers.
Twelve days later Wainwright was taken at Rotto by a 12ish ft White, then Peter Kurmann six months later down Bunno way on the 31st March, 12ft again.
Next was the surf skier off Mullas, 20th June reported as 3-4m, now he didn't get eaten but you're probably starting to see a pattern here. Seventeen days later Poddy and his mate get hassled diving just off Drummonds and get it all on GoPro. A couple of days after that there is fisherman hassled by a 3-4m White at Leeman and then on the 14th, Ben at Wedge, once again 3-4m.

All of these deaths were the result of a 10-12ft White in sustained and determined attacks, he was there for a meal, not to browse the menu and THAT is unusual. I reckon the only thing that saved Poddy or his mate is that they kept their cool and didn't freak out.

So yeah I think we have a "problem" shark that has figured out that humans are a very easy feed, even if we are a tad on the bony side. Hopefully if I'm right on this theory it has got bored and pissed off to South Africa or some such locale never to return, if not I reckon you can count on further carnage once the local waters cool to more suitable levels for a return visit.

Personally I think this fish was spawned in the waters surrounding the Neptune Islands and has been raised on a steady diet of tuna whilst swimming around funny looking seals in cages. It's only 4-8 yrs old and there's lots to eat in it's migratory path from South Oz to the Mid West as it follows the changing water temps throughout the year, plenty of Snapper, Sambos, Groper and Dhuies as it ventures West. Until it gets to that stretch from about Bunbury up to two Rocks where the inshore takings are a little slimmer and it has to make do with those damn bony seals. Here's hoping it doesn't develop a preference for them.

Both my kids are mad on surfing. They received new boards from santa this year but as of today they haven't been used. Work as well as the beach being closed three times over the last week have hampered their oppertunities. We left the beach just prior to the shark attack on the dolphin at mattams. When I spoke to the kids about it they were very concerned for the poor dolphins as they put it. Today is over cast and still and although they are only ten they recognise the conditions to be sharky. It hasn't dampered their enthusiasm for surfing but the current situation with the beaches closing and constant shark sitting worries me.

Bakesy i believe you are right surfing does help to make us better people and the joy of watching kids surf is fantastic and I prefer to surf with the kids as these days I seem to get more out of it. I just hope the experts can work out a solution to the problem. In the mean time I ballance keeping the kids safe and allowing them to surf.

rbl said...

The most annoying thing though is the greensters that talk about saving the white but go spearfishing themselves.

This, much like all the content of your posts, doesn't make the slightest bit of sense.

Care to elaborate; but in English this time?

sporto said...
Commercial fishing is destroying the natural balance in the ocean. You wonder why the apex predators are coming closer to shore? Bad times.....

Did you know that one of the current proposals to help with our shark problem. One that i have heard justified by a RECFISH west board member is to let commercial fishing back in to our metro waters[}:)] The commercial fishermen are saying that the sharks are only in close due to the high number of feed available. (IE fish stocks). SO therefor if the government was to agree to a re introduction to commercial fishing in our metro waters, less fish in total so therefor less sharks

To be 100% transparent on MY OPINION of this. I think its one of the most stupid arguemnets i have ever heard or argued, but that seems to be what we are dealing with

That's not surprising from RECFISH.
Some of the 5hit we have to listen to from them is not only mind boggling, but also quite scary.

jbshack said...

doggie said...

jbshack said...

sporto said...
Commercial fishing is destroying the natural balance in the ocean. You wonder why the apex predators are coming closer to shore? Bad times.....

Did you know that one of the current proposals to help with our shark problem. One that i have heard justified by a RECFISH west board member is to let commercial fishing back in to our metro waters[}:)] The commercial fishermen are saying that the sharks are only in close due to the high number of feed available. (IE fish stocks). SO therefor if the government was to agree to a re introduction to commercial fishing in our metro waters, less fish in total so therefor less sharks

To be 100% transparent on MY OPINION of this. I think its one of the most stupid arguemnets i have ever heard or argued, but that seems to be what we are dealing with

Chumming should be banned within less than 6km of the shoreline as well imo.

Theres a yellow Chivers that fishes' often of Trigg (oops mentioned a secret spot) and i have on occasion noticed ive been sitting in his burley slick[}:)]

Some weekends there is heaps of boats and bloody slicks everywhere, no wonder the sharks come in for a look.

Geez, well done. You ALMOST constructed a coherent post.
All those special classes must be paying off. Maybe in a few years you might actually say something that makes sense. I'm not holding my breath, but it's good for courageous people like you to have a goal to work towards.

Here, this is for you. You've earned it.

No, really, I meant it. I'm proud that his spelling and syntax is improving. You can almost see what he's trying to say. It's important that we nurture his development.

I was at mettams today. Well, very close to mettams on my own at a dodgey rock that I always surf. The waves were small, maybe knee with odd waist. Between waves it was like a lake. I saw a big splash about 5 metres behind me and water moving, I paddled to the shore real quick. I got to the shore and an older lady and a young girl asked if I saw that shark out there. I said no but I saw a big splash and raced in. They said they definately saw a fin but if it was a dolphin they were waiting for it to resurface. It was scary. I was all by myself, mettams people maybe 100 metre away. Still not sure what it was, maybe a seal or dolphin. But I was scared and the two people who were watching at the look out verified that they saw something.

subasurf said...
No, really, I meant it. I'm proud that his spelling and syntax is improving. You can almost see what he's trying to say. It's important that we nurture his development.

You crack me up dude....
Like I said you can tell you are from Cott.
And by the way whats wrong with iced coffee...liquid gold that stuff.

Don't worry suba, Cotts ok. There's a good wave at tea rooms.

But interestingly, according to Suba, it is ok to kill (or seriously maim) the befarkers out of a land animal with a bow and arrow (which would be a very inhumane way to die, even for vermin):

http://www.hotbite.com.au/forum/showthread.php?7106-banning-bowhunting-in-WA&p=62686#post62686

Is it just me, or is this attidute a little inconsistent with the attitudes expressed by him on this forum?

This is a bit of a rumour I heard over a beer or two, maybe some of you in the know can confirm or tell me if its another urban metro shark myth...

About 5 years ago commercial fishing/longlining was banned in the metro area, most years the by catch on sharks (Great whites ?) was ~ 1000 all in the 1.5-2m range. If this was the case this would explain the increase in shark numbers seen if the GWS grows to 3m after 4-5years thats why there are more about if less are been taken out by longliners and more bait fish about in general.

I personnal think that there are heaps more water users in the water all the time, fly in fly out, RDO's increase in population and free time has all meant I see more people surfing, ski paddling, fishing than in years past. I know that a mid week lunch time surf 5 years ago would have been just a couple out now its always busy. Older surfers staying in the sport longer and plenty of 50 plus blokes swimimng and paddling the coast.

More people in the water and social media means more people know about the sharks, question is have they always been there in these numbers or increased, 5 years ago if I saw a shark I would tell my mates and thats about it, now it seems if I seen a shark its on SLSWA site or shark alarm or seabreeze within the day.

Hasnt stopped me getting in the water yet...

Are you serious, Trevor?

There's a bit of a difference between hunting overpopulated animals deemed a pest and killing animals deemed endangered...

regardless, that was years ago mate. People's attitudes can change, although I still have no issue with hunting.