Jradedmondo said...

14m would buy a ****load of whatever they wanna do with it, i'm a lifesaver so i see a few sharks everynow and then, in my honest opinion the media overplays the whole shark thing, shark nets dont really do anything like someone said most sharks are caught on the inside, i haven't seen a shark caught on the outside, shark nets are around 100-150m long and have about 5m of net that sits a couple of metres off of the bottom, if a beach is 2-3km long not much of it is covered by net, most of the "general public" are unaware of this, anyway the mostly are not there for about a 1/4 or more of the year and normally get rotated between beaches, if i dived in SA or WA i would buy a shark shield as most of the sharks or on the larger side there and i have seen that they actually do work, honestly if any of this scared me i wouldn't do anything in the ocean


Jarryd

subasurf said...

White sharks are not known to be territorial in the sense that you're referring to.
It's more of them staying in an area for specific reasons (breeding, feeding) more so than setting up a territory. It's a part of being a migratory fish.

Nets are just a terrible approach to keeping swimmers safe. They don't offer much protection and they cause plenty of damage. A better alternative to creating a barrier is to us a solid mesh net around large areas of beach. You get proper protection, animals don't get caught in it, it provides structure for other marine creatures to live on....only problem is it is ugly and expensive and is sure to have other issues which I do not know about.

subasurf said...

I'm sure the deter them on a certain level, but doubtful the do on a level that actually increase swimmer safety.

I think that the fact that the majority of the sharks are entangled on the swimmer side of the nets supports the theory.

FormulaNova said...



Nah, I would hazard a guess that the reason sharks don't get caught on the outside of the nets, is that they are trying to get back to safety, i.e. into the ocean. When they are already on that side, they aren't going to get caught.

You suggest that it is doubtful that nets deter sharks, but use the suggestion that they are found on the swimmer side to support that. They are not the same thing. Finding sharks in nets does not support either that they deter or that they encourage sharks. You have no data to support this at all, and I would argue that logic suggests that getting caught does deter them.

If they are caught on the swimmer side, you would argue that they are indeed deterred, as they are by definition trapped. That would deter most animals.

Not being a shark, I am making the assumption that running into a net in the water, that is almost invisible to me, would deter me from hanging around there, but I could be wrong.

(No, I am not trying to call you out, I am just trying to discuss this, and hopefully learn something along the way.)

Earlier that morning, a fisherman spotted two killer whales-rarities around the Farallones-feeding on a sea lion. Several hours later, Pyle heard from the captain of a tourist vessel: "Get out here fast. A killer whale's got a shark!"

Pyle sped out in his research boat and found the two killer whales, which appeared to be a mother and calf. "The calf was dragging the shark through the water," Pyle recalls. After five minutes, a chunk of liver popped out of the 10-foot great white shark. As the calf ate the liver, Pyle filmed the sinking carcass with an underwater video camera.

The incident was beyond odd. No one-anywhere-had ever recorded seeing a killer whale attack a great white. And then something even stranger happened: The sharks of the Farallones vanished.

"On the hour of the attack, Tipfin abruptly dropped to 500 meters and headed west," says Pyle. "He swam all the way to Hawaii."

seafever17 said...



I have worked at sea for twenty years and a good amount of that was cray fishing along the W.A coast.

Everyday, yes, everyday the boats i worked on were followed by sharks. Mostly whalers and occassional tigers. Never seen a white. I asked the skipper who was 60 years old and had been fishing since he was a boy about the sharks and he said they never used to follow the boats but over the years had come to associate the sound of the motors with a free feed. We used herring, cowhide,Kangaroo cubes, tuna heads as bait and each day we pulled the puts we would change it.

The following sharks consumed everything.

We often fished south of Geraldton at Flatrocks and would be 2 or 300 meters away from the surf break and could see guys riding waves. Looking down over the handrail we could easily see a dozen sharks. Probably 40 /50 boats working out of Geraldton and More out Dongara,Freshwater,Horrocks and a heap of other ports along the W.A coast all the way around to the bight. Each with their own pack of sharks. Thats a lot of sharks.
Has a shark been near you in the water. Undoubtedly so. Did you know it? Very unlikely. Sharks can learn behavior as evidenced by the cow hide and following boats for food. Are they in the process of learning to associate us with food? No. There has been very few attacks compared to the millions upon millions of individual pieces of bait it took to "teach" them to associate boat engines with food.
However random stuff can happen in strange patterns. No attacks for X amount of time and then 3 amount in a short period. Strange yes. Evidence of a sudden change in shark behavior? No.
I think everyone agrees that sharks are the ultimate hunter.They would not still be here if they were not. They use the environment they reside in and its variances to improve their success.Previously learned behavior such as the following will never be "unlearned"

Attack at speed from depth
Use the turbid water at river out flows as concealment.
Use of low light for concealment
Hunt where the food is such as seal rookeries,
Follow migrations of large biomass such as whales.

Do all you can to minimise your exposure to the above and your odds of being on the wrong side of the ultimate survivor get very small indeed.

If all else fails and you are getting chewed by Mr. G. White just remember that their is no malice involved.Not like some thug kicking your door in to beat you up for your wallet.

He just needs you to get by for a bit.

those sharks are scavenging.
you probably never saw whites because they aren't scavengers. they are hunters. they prey on animals as big or bigger than humans and they hunt them.
I reckon it's all about the fight in the dog....

South africa get a lot of whites in close. Spearfisherman will regulary dive with and in amongst all other sharks (continue spearing), but when a white comes along they get out of the water

subasurf said...

Nets not only dont work (most sharks caught in nets are caught on the swimmer side) but they also cause havoc to the local marine life. Everyone knows this, yet some people, for some reason, still think it's a viable option.

As for the shark shield, it is pretty much proven technology. Several scientific papers have been released by elasmobranch biologists to support the evidence and the anecdotal evidence is astounding. There are several electronic shark deterrents on the market and the Aussie made 'Shark Shield' is by far the most effective and reliable. Problem with sharkshields is that tend to zap you from time to time but, if you're a regular diver, it may be worth the investment. Having said that, I would never go diving with/near someone that had one. The zap hurts. You can also get them for surfboards but they're 5hit.

At the end of the day, the only way for people to be 100% safe from sharks is to stay on land. Otherwise, sack up and get wet. I'm stoked about the intended funds for further shark research from a researcher's point of view more so than for swimmer's safety. The more we know about white sharks (at the moment we know almost nothing) the more we can do to protect them (still very much endangered) and even possibly unlock the 'secret' as to why they seams to be hanging around coastal waters when their usual prefered habitat is off the continental shelf.

myusernam said...
\
Spearos report that they actually bring in more sharks to see what is there, but then once they come in too close it shoes them away

FormulaNova said...



Is that the guy that was taken while wearing one, but it wasn't turned on, or it wasn't used correctly?

If it is, they had a coroner's inquiry where they found that it wasn't used correctly. They had only turned it on when they were going up or down, whereas they were meant to leave it on all the time to deter the shark from coming in.

myusernam said...



so am i and the buzz is around forums and among club divers is that they suspect it actually
brings them in for a look. have you not heard that? I dont care either way as I think they are a piece of shxt.