Why not take them off the endangered species list, allow then to be fished?

Thanks for the links 69er, it's sobering to see what little information we know about white sharks.

Some interesting points I pulled out I thought I may share (cut and pasted with some editing, hopefully without too much cherry picking):

There is currently no reliable estimate of the total size of the Australian white shark population and therefore no robust measure of population trends or status. This lack of information makes it difficult to assess the effectiveness of any actions undertaken to conserve the species. It's suggested that there's a population size of 1500 individuals for the Australian population, however this should be considered a minimum estimate. The lack of reliable population size estimates is due partly to the scarcity of white sharks and also to the difficulty in distinguishing population changes from the high rates of inter-annual variability in the numbers observed within any one site or region. Recent genetic evidence provides support for maternal structuring between the eastern and south-western coastal regions. So 69ers estimate of 750 white sharks on the west and south-west coasts is reasonable.

White sharks are generally highly mobile off the WA coast and undertake rapid long-distance movements, interspersed by periods of temporary residence. White sharks may be encountered off metropolitan Perth and the South-West coasts of WA at any time of the year. Tagged white sharks were most abundant in metropolitan waters between late winter and early summer and least abundant during late summer and autumn. Decreasing water temperatures generally increase the incidence of white shark attacks.

Despite these seasonal occurrence patterns, the direction and timing of individual white sharks’ movements are highly variable. The data does not support the theory that white sharks follow the humpback whale migration northwards along the WA coast during winter, though movements up the west coast will result in them encountering whales along much of their migration route. The data also does not support that sharks are attracted to the increasing number and densities of long-nosed fur seal colonies off the South and lower West coasts of the State. There was only limited evidence that white sharks regularly returned to the same locations in WA. Tagged white sharks were generally only detected in the metropolitan region for few days at a time.

It is suggested that white sharks prefer deeper offshore shelf waters, at least while travelling. There was a high abundance of tagged-sharks detected by Cockburn Sound/Garden Island receivers in Spring, coinciding with the seasonal formation of spawning aggregations of snapper in the Sound. Spawning aggregations of demersal scalefish might therefore also attract sharks to other locations along the WA coastline. White sharks may also opportunistically take advantage of less predictable prey sources and may occur in relatively high numbers at different locations and times of year.

Despite significant advances in the knowledge base concerning the white shark in Australian waters over the past decade, continuation of research into their ecology and biology, as well into causes of anthropogenic mortality, will assist in developing programs to aid the long-term management of white sharks.

Dunno, if any of this helps, there still seems to be plenty of questions that are unanswered.

Refs:

McAuleya, R.,Bruceb, B., Keaya,I., Mountforda, S. & Pinnella, T. 2016. Evaluation of passive acoustic telemetry approaches for monitoring and mitigating shark hazards off the coast of Western Australia. Fisheries Research Report No. 273, Department of Fisheries, Western Australia. 84pp.

Environment Australia. 2013. Issues Paper for the White Shark (Carcharodon carcharias).2013.

Select to expand quote

jayet said..
Thanks for the links 69er, it's sobering to see what little information we know about white sharks.

Some interesting points I pulled out I thought I may share (cut and pasted with some editing, hopefully without too much cherry picking):

There is currently no reliable estimate of the total size of the Australian white shark population and therefore no robust measure of population trends or status. This lack of information makes it difficult to assess the effectiveness of any actions undertaken to conserve the species. It's suggested that there's a population size of 1500 individuals for the Australian population, however this should be considered a minimum estimate. The lack of reliable population size estimates is due partly to the scarcity of white sharks and also to the difficulty in distinguishing population changes from the high rates of inter-annual variability in the numbers observed within any one site or region. Recent genetic evidence provides support for maternal structuring between the eastern and south-western coastal regions. So 69ers estimate of 750 white sharks on the west and south-west coasts is reasonable.

White sharks are generally highly mobile off the WA coast and undertake rapid long-distance movements, interspersed by periods of temporary residence. White sharks may be encountered off metropolitan Perth and the South-West coasts of WA at any time of the year. Tagged white sharks were most abundant in metropolitan waters between late winter and early summer and least abundant during late summer and autumn. Decreasing water temperatures generally increase the incidence of white shark attacks.

Despite these seasonal occurrence patterns, the direction and timing of individual white sharks’ movements are highly variable. The data does not support the theory that white sharks follow the humpback whale migration northwards along the WA coast during winter, though movements up the west coast will result in them encountering whales along much of their migration route. The data also does not support that sharks are attracted to the increasing number and densities of long-nosed fur seal colonies off the South and lower West coasts of the State. There was only limited evidence that white sharks regularly returned to the same locations in WA. Tagged white sharks were generally only detected in the metropolitan region for few days at a time.

It is suggested that white sharks prefer deeper offshore shelf waters, at least while travelling. There was a high abundance of tagged-sharks detected by Cockburn Sound/Garden Island receivers in Spring, coinciding with the seasonal formation of spawning aggregations of snapper in the Sound. Spawning aggregations of demersal scalefish might therefore also attract sharks to other locations along the WA coastline. White sharks may also opportunistically take advantage of less predictable prey sources and may occur in relatively high numbers at different locations and times of year.

Despite significant advances in the knowledge base concerning the white shark in Australian waters over the past decade, continuation of research into their ecology and biology, as well into causes of anthropogenic mortality, will assist in developing programs to aid the long-term management of white sharks.

Dunno, if any of this helps, there still seems to be plenty of questions that are unanswered.

Refs:

McAuleya, R.,Bruceb, B., Keaya,I., Mountforda, S. & Pinnella, T. 2016. Evaluation of passive acoustic telemetry approaches for monitoring and mitigating shark hazards off the coast of Western Australia. Fisheries Research Report No. 273, Department of Fisheries, Western Australia. 84pp.

Environment Australia. 2013. Issues Paper for the White Shark (Carcharodon carcharias).2013.

I think you'll find the 750 figure relates to adult/breading age great white sharks. So around 3.2 to 3.5 m depending on sex.

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Zed said..
Why not take them off the endangered species list, allow then to be fished?

Think about the question The same answer that put them on the list, is a good place to start.

Thanks JB,

Yes the info on population sizes relate to the effective, or breeding, population.

For white sharks males mature at 3.6–3.8 m (7–9 years) and females at 4.5–5.0 m (12–17 years).

This is the worst and most done to death debate topic ever where everyone becomes a shark expert . Kind of gives me the sharts

I think its important to note that although the "Cull" did not remove any GWS. There was a sudden stop in people being attacked.

If you look at irrefutable facts, not just data generated by a few sharks people have managed to pop a tag into that are supposed to be some indication of the movements of non pack animals...ie the GWS population off the WA coast, measured by a few locations.

There was an incline in frequency of GWS attacks up until 2014. Then "The Cull" which was unfortunately carried out at the wrong time to actually cull any GWS may have done more than it has been credited for.

Its been said that a chemical is released when sharks are killed which scares away other sharks. It may well be that the "Cull" was more effective than people first thought & more research is required. Even JB doesn't mind culling bull sharks, so maybe we should kill a few bull sharks along the coast at regular intervals & see how that goes. I'm more serious than people may think & its better than nothing.

At the end of the day I still believe we do not need to fully protect GWS anymore & I'm all for removing sharks deemed to be "threatening".

I would also like to see a quicker response to threatening sharks in not only systems to relay info to people in the water immediately. An App is not appropriate, people need signage, PA systems & more importantly people with guns to shoot the bastards rather than responding 12 to 24 hours later with a few baited lines.

Select to expand quote

MickPC said..
I think its important to note that although the "Cull" did not remove any GWS. There was a sudden stop in people being attacked.

If you look at irrefutable facts, not just data generated by a few sharks people have managed to pop a tag into that are supposed to be some indication of the movements of non pack animals...ie the GWS population off the WA coast, measured by a few locations.

There was an incline in frequency of GWS attacks up until 2014. Then "The Cull" which was unfortunately carried out at the wrong time to actually cull any GWS may have done more than it has been credited for.

Its been said that a chemical is released when sharks are killed which scares away other sharks. It may well be that the "Cull" was more effective than people first thought & more research is required. Even JB doesn't mind culling bull sharks, so maybe we should kill a few bull sharks along the coast at regular intervals & see how that goes. I'm more serious than people may think & its better than nothing.

At the end of the day I still believe we do not need to fully protect GWS anymore & I'm all for removing sharks deemed to be "threatening".

I would also like to see a quicker response to threatening sharks in not only systems to relay info to people in the water immediately. An App is not appropriate, people need signage, PA systems & more importantly people with guns to shoot the bastards rather than responding 12 to 24 hours later with a few baited lines.

Mick the current run of Salmon and the gutting, heading of fish on the beach right next to your favorite break has more to do with the attack on Ben than any thing else I have seen for years.

Select to expand quote

IFocus said..

MickPC said..
I think its important to note that although the "Cull" did not remove any GWS. There was a sudden stop in people being attacked.

If you look at irrefutable facts, not just data generated by a few sharks people have managed to pop a tag into that are supposed to be some indication of the movements of non pack animals...ie the GWS population off the WA coast, measured by a few locations.

There was an incline in frequency of GWS attacks up until 2014. Then "The Cull" which was unfortunately carried out at the wrong time to actually cull any GWS may have done more than it has been credited for.

Its been said that a chemical is released when sharks are killed which scares away other sharks. It may well be that the "Cull" was more effective than people first thought & more research is required. Even JB doesn't mind culling bull sharks, so maybe we should kill a few bull sharks along the coast at regular intervals & see how that goes. I'm more serious than people may think & its better than nothing.

At the end of the day I still believe we do not need to fully protect GWS anymore & I'm all for removing sharks deemed to be "threatening".

I would also like to see a quicker response to threatening sharks in not only systems to relay info to people in the water immediately. An App is not appropriate, people need signage, PA systems & more importantly people with guns to shoot the bastards rather than responding 12 to 24 hours later with a few baited lines.

Mick the current run of Salmon and the gutting, heading of fish on the beach right next to your favorite break has more to do with the attack on Ben than any thing else I have seen for years.

More than likely, great thought there.

Select to expand quote

IFocus said..

MickPC said..
I think its important to note that although the "Cull" did not remove any GWS. There was a sudden stop in people being attacked.

If you look at irrefutable facts, not just data generated by a few sharks people have managed to pop a tag into that are supposed to be some indication of the movements of non pack animals...ie the GWS population off the WA coast, measured by a few locations.

There was an incline in frequency of GWS attacks up until 2014. Then "The Cull" which was unfortunately carried out at the wrong time to actually cull any GWS may have done more than it has been credited for.

Its been said that a chemical is released when sharks are killed which scares away other sharks. It may well be that the "Cull" was more effective than people first thought & more research is required. Even JB doesn't mind culling bull sharks, so maybe we should kill a few bull sharks along the coast at regular intervals & see how that goes. I'm more serious than people may think & its better than nothing.

At the end of the day I still believe we do not need to fully protect GWS anymore & I'm all for removing sharks deemed to be "threatening".

I would also like to see a quicker response to threatening sharks in not only systems to relay info to people in the water immediately. An App is not appropriate, people need signage, PA systems & more importantly people with guns to shoot the bastards rather than responding 12 to 24 hours later with a few baited lines.

Mick the current run of Salmon and the gutting, heading of fish on the beach right next to your favorite break has more to do with the attack on Ben than any thing else I have seen for years.

Good chance mate, I've only lived here 7 years but I've never seen it like this before. Has been like a week or two, maybe 3 in the past. But its what coming up to 7 or 8 weeks now. I'm not sure, definately seeing way more fisherman & a lot of people have complained about it. You bring up another important point. We also get a line of baited cray pots out the back between my home break & where one of the recent tragedies took place. I've wondered if that attracts sharks. Gotta say, there seems to be a bit of a contradiction with some people saying sharks are coming in closer coz they don't have enough to eat. But their stocks of seals, whales & salmon seem too be much higher than the last few decades. Just so many variables, I honestly don't think anyone has a clear idea of what is going on...but I do agree with you that such practices do not help surfer safety.

Mick,

This was my first year cray fishing and yeah it was crazy how many sharks were out there.

There were over a hundred pots along 3 mile reef, all with rotten fish heads. The sharks follow the boats 'cause they know they can get a free feed from when you swap the bait out.

We were surfing little island a bit up till then but stopped during cray season!

I'm sure there's plenty of crew that can tell better stories about this than me.

Yep think its pretty much unacceptable to fillet and dump fish carcasses up north for obvious reasons. Why does everyone chum the beaches here?

Select to expand quote

jayet said..
Thanks for the links 69er, it's sobering to see what little information we know about white sharks.

Some interesting points I pulled out I thought I may share (cut and pasted with some editing, hopefully without too much cherry picking):

There is currently no reliable estimate of the total size of the Australian white shark population and therefore no robust measure of population trends or status. This lack of information makes it difficult to assess the effectiveness of any actions undertaken to conserve the species. It's suggested that there's a population size of 1500 individuals for the Australian population, however this should be considered a minimum estimate. The lack of reliable population size estimates is due partly to the scarcity of white sharks and also to the difficulty in distinguishing population changes from the high rates of inter-annual variability in the numbers observed within any one site or region. Recent genetic evidence provides support for maternal structuring between the eastern and south-western coastal regions. So 69ers estimate of 750 white sharks on the west and south-west coasts is reasonable.

White sharks are generally highly mobile off the WA coast and undertake rapid long-distance movements, interspersed by periods of temporary residence. White sharks may be encountered off metropolitan Perth and the South-West coasts of WA at any time of the year. Tagged white sharks were most abundant in metropolitan waters between late winter and early summer and least abundant during late summer and autumn. Decreasing water temperatures generally increase the incidence of white shark attacks.

Despite these seasonal occurrence patterns, the direction and timing of individual white sharks’ movements are highly variable. The data does not support the theory that white sharks follow the humpback whale migration northwards along the WA coast during winter, though movements up the west coast will result in them encountering whales along much of their migration route. The data also does not support that sharks are attracted to the increasing number and densities of long-nosed fur seal colonies off the South and lower West coasts of the State. There was only limited evidence that white sharks regularly returned to the same locations in WA. Tagged white sharks were generally only detected in the metropolitan region for few days at a time.

It is suggested that white sharks prefer deeper offshore shelf waters, at least while travelling. There was a high abundance of tagged-sharks detected by Cockburn Sound/Garden Island receivers in Spring, coinciding with the seasonal formation of spawning aggregations of snapper in the Sound. Spawning aggregations of demersal scalefish might therefore also attract sharks to other locations along the WA coastline. White sharks may also opportunistically take advantage of less predictable prey sources and may occur in relatively high numbers at different locations and times of year.

Despite significant advances in the knowledge base concerning the white shark in Australian waters over the past decade, continuation of research into their ecology and biology, as well into causes of anthropogenic mortality, will assist in developing programs to aid the long-term management of white sharks.

Dunno, if any of this helps, there still seems to be plenty of questions that are unanswered.

Refs:

McAuleya, R.,Bruceb, B., Keaya,I., Mountforda, S. & Pinnella, T. 2016. Evaluation of passive acoustic telemetry approaches for monitoring and mitigating shark hazards off the coast of Western Australia. Fisheries Research Report No. 273, Department of Fisheries, Western Australia. 84pp.

Environment Australia. 2013. Issues Paper for the White Shark (Carcharodon carcharias).2013.

This report is outdated, the current estimate of WAs population of White Sharks is somewhere between 3500 to just over 5000. This comes directly from Professor Peter Harrison who was instrumental in having the species listed as vulnerable in the first place. That's not to say that they should be taken off the list, just putting the correct information on the table. There was a very interesting interview with him on 720 yesterday, still available on their website if you go to the mornings section you can play it back.




Play on.....

Cheers Smicko,

Interesting interview, as I understand it Fisheries WA are yet to release the data supporting the estimated higher numbers of white sharks?

Doesn't change much, more research is still needed to support any change in their conservation status.

Link can be found here if others are interested:

radio.abc.net.au/programitem/pexQX9MWXL?play=true

Starts at about 3:20.

Oh so now estimates by Professor Peter Harrison who was instrumental in having the species listed as vulnerable in the first place are not as important. It needs support from fisheries.

I have been highly skeptical of statements made by marine biologists for a long time now, they've lost my trust. Unfortunately the way things are with trying to attract government funding to continue research & for some people to continue being employed. There is no alternative other than to say more research is required in the face of any other option.

Cheers my ipad is being a dick and wouldn't let me post the link. And yeah, no way are they coming off the vulnerable list anytime soon.
I'm buggered if I know what the solution is but I'm not up for open slather drum lines, collateral damage is too high. I have no problem with the shark in Falcon being necked last week, none at all but not keen on drumlines out all the time.

As to why we find ourselves in the situation we're in I reckon it's a combination of factors;
1. There's more around than there was 20 years ago.
2. La Niña. We're just coming into the strongest La Niña pattern ever forecast. The second strongest we have ever experienced was from 2011-2013, right when the $hit hit the fan last time.
3. Year round cray season, we never seemed to have anywhere near the numbers of Whites close inshore when the pots were out of the water from June to November. They were a relatively common sight out around the whales at that time of year but seemed to stay there. Now we have a big **** off berley trail leading inshore right through White season.
4. ****ing cage diving.

Select to expand quote

MickPC said..
Oh so now estimates by Professor Peter Harrison who was instrumental in having the species listed as vulnerable in the first place are not as important. It needs support from fisheries.

I have been highly skeptical of statements made by marine biologists for a long time now, they've lost my trust. Unfortunately the way things are with trying to attract government funding to continue research & for some people to continue being employed. There is no alternative other than to say more research is required in the face of any other option.

Yeah you're right Mick, they're always gonna push for more research.

I just don't think an extended cull is a viable option. Take out problem animals by all means, just like last week. But having baits permanently in the water during the migration will bring them in close just like the pots do.

I really think the solution is to retrain them to avoid humans and stop berleying our inshore coastline during their migration. Ban cage diving, spend five years with the current cage boat operators being gov funded to berley the bastards up then hit em with a taser so they learn to bolt when they hear boats and smell berley. The amount of times I've seen a big Noah show up within minutes of the anchor chain running out is nuts. And secondly reintroduce the closed season on the crays or at least make it a minimum of 10ks offshore, from June to December.

Select to expand quote

smicko said..

MickPC said..
Oh so now estimates by Professor Peter Harrison who was instrumental in having the species listed as vulnerable in the first place are not as important. It needs support from fisheries.

I have been highly skeptical of statements made by marine biologists for a long time now, they've lost my trust. Unfortunately the way things are with trying to attract government funding to continue research & for some people to continue being employed. There is no alternative other than to say more research is required in the face of any other option.

Yeah you're right Mick, they're always gonna push for more research.

I just don't think an extended cull is a viable option. Take out problem animals by all means, just like last week. But having baits permanently in the water during the migration will bring them in close just like the pots do.

I really think the solution is to retrain them to avoid humans and stop berleying our inshore coastline during their migration. Ban cage diving, spend five years with the current cage boat operators being gov funded to berley the bastards up then hit em with a taser so they learn to bolt when they hear boats and smell berley. The amount of times I've seen a big Noah show up within minutes of the anchor chain running out is nuts. And secondly reintroduce the closed season on the crays or at least make it a minimum of 10ks offshore.

Sounds good to me mate...I agree with all the above plus making it simpler to remove threatening sharks without all the bureaucratic BS. As in simpler to remove sharks in a timely manner without time costly restrictions.

Thanks for the link Jayet!

even at 3500 that's obviously a lot more than I was aware , haven't seen this fisheries data that they're referring to ....But if it's up to the 5000 + mark then I would expect they would come off their current level,of protection if that's substantiated enough by the people like Proffesor Harrison.

GW fishing to quota could be on again in the not too distant.

Select to expand quote

smicko said...
Cheers my ipad is being a dick and wouldn't let me post the link. And yeah, no way are they coming off the vulnerable list anytime soon.
I'm buggered if I know what the solution is but I'm not up for open slather drum lines, collateral damage is too high. I have no problem with the shark in Falcon being necked last week, none at all but not keen on drumlines out all the time.

As to why we find ourselves in the situation we're in I reckon it's a combination of factors;
1. There's more around than there was 20 years ago.
2. La Niña. We're just coming into the strongest La Niña pattern ever forecast. The second strongest we have ever experienced was from 2011-2013, right when the $hit hit the fan last time.
3. Year round cray season, we never seemed to have anywhere near the numbers of Whites close inshore when the pots were out of the water from June to November. They were a relatively common sight out around the whales at that time of year but seemed to stay there. Now we have a big **** off berley trail leading inshore right through White season.
4. ****ing cage diving.

I reckon you are onto something in regards La Niña Mick. Also seems to coincide with best surf conditions which is a double whammy - seem to remember swells in 2011 to 2013 were much better and consistent then 2014 to 2015. This could be seen in that there was so much sand build up last year - not enough consistent swell to wash it away.

Don't get me started on El Niño though.

What I'm seeing now is a whole lot of information that's being shared, reviewed and disseminated , damn that's good, regardless of where people's opinions end up their view points are based on an active effort to seek and understand a variety of issues that may or may or may not contribute to a problem. bloody awesome gentlemen.

its problem solving, we do it every day in different ways when it impacts directly on ourselves and we have control over the effort that leads to the outcome, but we generally fail to do it on the big ticket items that others control and make decisions on for us.

i just wish the rest of the poultice could put the same level of thought into the policies that are developed on our behalf, without our control as opposed to being spoon fed bull #*%t and mis-information by the commercial and social media on all issues.

Ive got so more research to do and looking forward to the justifications and assumptions used for the numbers that Fisheris are projecting and more so the response from Proffesor Harrison once he's seen them, to me it's definately game changing .

Nice find smicko but the Professor is quoting the WA Department of Fisheries estimated numbers of between 3500 and 5400 in the SW of WA and not his own numbers. These numbers are a credible estimate based on their research but the research is ongoing which means the White Sharks protection will not be removed any time soon.

These numbers certainly sound a lot more realistic than 749!

Select to expand quote

Zuke said..
Nice find smicko but the Professor is quoting the WA Department of Fisheries estimated numbers of between 3500 and 5400 in the SW of WA and not his own numbers. These numbers are a credible estimate based on their research but the research is ongoing which means the White Sharks protection will not be removed any time soon.

These numbers certainly sound a lot more realistic than 749!

I remember this paper, it was what they based their estimates were the tried to work out possible numbers using breading cycles to estimate the number of sharks. From memory they estimated from the highest possible denominator and then doubled that also. It was released right as the drum lines started to roll out.

An estimate of around 10000 sounds familiar, but it was laughed down even by most fisheries officers.

Either way, whilst we all talk about killing sharks, nothing changes. We need real answers to beach safety today.

No one has even answer me how after killing 100, 200, 5000 great white sharks, will i be protected when a large shark swims up to me in the water

Select to expand quote

Zuke said..
Nice find smicko but the Professor is quoting the WA Department of Fisheries estimated numbers of between 3500 and 5400 in the SW of WA and not his own numbers. These numbers are a credible estimate based on their research but the research is ongoing which means the White Sharks protection will not be removed any time soon.

These numbers certainly sound a lot more realistic than 749!

That number has always been mature/breading sharks. Ive never peddled that of a total population. But it does get mis quoted a lot.

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Surf69 said..
It’s considered that there is a population of GW’s that are transient along the WA coast of about 750 +/-. Sounds like a lot but it’s not and certainly isn’t sustainable.

I wasn't quoting you jb and I don't know where Surf69 got it from.

Hey Zuke...sounds more realistic based on .....?

Numbers are going to varied based on quite significant variations in Target Data in the case we are looking at fish with the potential to pose an immediate threat i would have thought?

I highly respect Professor Harrisons approach and he's a damn fine gentleman, he's always been very careful about what he says and only commits to what can be clearly demonstrated. He wont give an opportunity for the media to "Grab" and misrepresent any comments that he puts out there ( Unlike our former PM Mr Abbot) HE is also quite blunt about what is required and what isn't with regards to the impact on a range of issues, he's not the type to say save everything and leave it all alone, because he's a nature lover, hippie or what ever, he'll be very realistic about the "Practical Reality" of symbiotic relationships between people and nature.

He made comment on a fisheries projection associated with GW populations and what that range was, but he also stated that he hadn't seen the report, me either. Did he mention it was to be released soon? I cant remember and that's why i ask'.... but if that's the fact and and those numbers have been put out there before the release of the report and he wasn't one of the first to "Peer" review the data, im still at this stage a touch skeptical.

Anyway i respect that the WA govt rely on the Dept of Fisheries SME's for a lot of the info and i know how hard it is to get data out there - particularly given " The Terms of Reference" that may or may not have been quite specific.

I will say that if the population of GW's that could pose a threat to humans along the WA coastline exceeds the 4000 range and that can be fairly well accepted by the EPA etc, they are likely to come off protection, it wont happen over night, but will happen IMO.

Select to expand quote

Zuke said..

Surf69 said..
It’s considered that there is a population of GW’s that are transient along the WA coast of about 750 +/-. Sounds like a lot but it’s not and certainly isn’t sustainable.

I wasn't quoting you jb and I don't know where Surf69 got it from.

Link supplied earlier, within that site there are other links also should move you around to give you the picture. Fisheries also field the same data and references based on GW's transient into shared habitats. (i.e.- close to coastal populations of people) The imminent threat. Have't seen this other Data,Nor has the Mr's or Harrison as mentioned so, the Ball game as mentioned may well have changed ?

Either way, i bet you know a hell of a lot more about it now than you did a week ago?

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Surf69 said..
Hey Zuke...sounds more realistic based on .....?

Based on all the anecdotal evidence over the past 5 to 10 years. The attacks, personal encounters, feedback from other water users such as surfers, divers and professional fisherman. I know this is not scientific evidence and is not used by scientists hence the term anecdotal evidence but this does not make it wrong either.

I'm not having a go at you Surf69 but you quoted the 750 figure, "It’s considered that there is a population of GW’s that are transient along the WA coast of about 750 +/-." and that sounded unrealistically low to me personally based on my experience and the above mentioned anecdotal evidence.

As with smicko, I don't want to see drum lines up and down the coast just off our beaches but I didn't shed a tear when the one off Mandurah was caught either.

Select to expand quote

jbshack said..

Zuke said..
Nice find smicko but the Professor is quoting the WA Department of Fisheries estimated numbers of between 3500 and 5400 in the SW of WA and not his own numbers. These numbers are a credible estimate based on their research but the research is ongoing which means the White Sharks protection will not be removed any time soon.

These numbers certainly sound a lot more realistic than 749!

I remember this paper, it was what they based their estimates were the tried to work out possible numbers using breading cycles to estimate the number of sharks. From memory they estimated from the highest possible denominator and then doubled that also. It was released right as the drum lines started to roll out.

An estimate of around 10000 sounds familiar, but it was laughed down even by most fisheries officers.

Either way, whilst we all talk about killing sharks, nothing changes. We need real answers to beach safety today.

No one has even answer me how after killing 100, 200, 5000 great white sharks, will i be protected when a large shark swims up to me in the water

Because if there are 10,000 GWS, and 5000 are killed, there will be a 50% less chance of one swimming up to you in the first place.