Was reading the south east queensland fishing monthly yesterday and there was a very interesting letter published about snapper stocks in south east queensland, was a real eye opener, i know myself that if you go back 3 years much of the posts in the estuary-bay section on this site were about snapper catches in the bay using soft plastics yet the last 12 months such posts are getting rare, for myself snapper catches in the bay fell into a hole in april 2007 and have never looked like coming back like they were, its a very interesting read, i might just buy it and type it out..anyone else see it?.
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LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERS LETTERSsnapper limit Slow Down
Dear Editor,
I was interested to read your take on the likelihood of decreased bag limits and such in South East Queensland and, in particular, for snapper (Qld Fishing Monthly Vol 22. No.2. Dec 2008 "From the Editors Desk"). My take is a little different to yours and I will attempt to clarify my main dissentions. My comments in the following relate only to snapper in SE Qld waters with probable implications for Northern NSW waters also:
• Long-term sustainability of a fish species
There are many thoughts on what proportion of the spawning stock need to survive to maintain long-term sustainable fish stocks (long-term = >100 years; for example: Leaving your children’s children some chance of catching a fish).
There are numerous estimates in Fisheries Research Journals that suggest that somewhere between 30-40% of the virgin biomass (untouched resource) spawning stock need to survive annually, except for extremely long lived species, in order to ensure long term sustainability. Some may argue that snapper in SE Qld are a different species\life history\habitat availability and so on and require a much lower percentage survival, but I suggest they would be on dangerous ground.
• Concept of virgin biomass
The concept of virgin biomass is admittedly a slippery concept, but in the case of snapper stocks in SE Qld, the earliest reports and stock estimates we can rely on are the published works of the likes of Wellsby who fished both inshore Moreton Bay and Offshore, at least between Caloundra and the Tweed, in the late 1800s and early 1900s.
But what can these reports tell us? That snapper were at least seemingly more common in those days than now? If so, then we need a way of testing these conclusions.
The only way to test the veracity of these claims is to duplicate the exact conditions of the ‘Wellsby’ reported catches of, for example, 500+ squire (1-6kg) around Flat Rock in an afternoons fishing.
In order to be scientifically controlled, one would also need to duplicate the gear of the day, the exact season, and even the weather, if possible. Duplicating such an experiment presents problems and relies critically on season, time of day, bait, tackle and weather.
It is my guess that if you took a team of anglers to those locations with no mod-cons (no GPS, sounder, radar, etc) in daylight hours to duplicate the feat, their catch rate would be zero snapper for the afternoon.
• What can this tell us?
Taking aside the anecdotal reports of Wellsby catching 500-800+ fish a day, let’s use a conservative estimate of catching 100 squire (1kg+) a day back in 1900. Using the amazing technology/gear we have today to catch a 100 squire at Flat Rock (ignoring bag limits and zoning) would be quite a feat. Therefore, using gear from the 1900s to catch today’s squire I would estimate a total catch rate of 10 fish per day. So, 100 Wellsby squire/10 modern squire = 10% of surviving virgin biomass.
In reality, the true figure is more likely to be less than 1% of virgin biomass. This conflicts dramatically with the 30-40% suggested by research.
• But that’s just Flat Rock, what about other areas?
The same scenario is played out up and down the SE Qld Coast. Produce any catch records for snapper from a fishing club dating back to the 1900s and attempt to reproduce those catch rates using the same gear\bait\season\time.
It is my guess that similar ratios of existing virgin biomass will be revealed. And I am fairly sure that that ratio will be less than 1% of virgin biomass.
• Why is this massive decline not been noticed\recorded by anglers?
There are many studies that have examined just that question. The answer lies in the generational acceptance of what we are born into, as being the ‘baseline’ for our mental measurements of how things are changing. So each generation only gauges against what they grew up with.
Every generation has said the same damn thing, "Fishing has gone bad since I was little!" In fact, Wellsby mentions his father as saying something akin to "the fishing in the BrisbaneRiver is stuffed" in the late 1800’s compared to his childhood!
• What about those who say they catch more snapper in MoretonBay today than ever?
This is all about the ‘Effort Creep’ syndrome. As new technology is more available, the home ranges\feeding times\precise locations and such, allows more anglers to catch fish that would never have been subjected to fishing pressure.
I have a good mate who swears he catches more snapper now in MoretonBay than ever before and, from his catch rates, he infers that snapper stocks are in good health. He uses plastics in daytime. My answer to test his theory is to revert back to the standard rig of using bait in daylight hours and see what you catch. Plastics work really well but you are just rounding up the last few fish using technology. More ‘Effort Creep’. It’s rounding up the ‘last few spawners’.
There are many cases in the literature where commercial fish stocks have held up under increasing pressure. For example, for the Atlantic cod catch rates actually increased each year as the species approached crash point. The cod distribution had contracted to an ever-decreasing area due to ever-increasing levels of exploitation, plus more efficient technology to detect\catch them. Of course the stock collapsed years ago and hasn’t shown any real ability to recover. One might be wondering whether a similar contraction is\has occurred in snapper stocks in SE Qld.
• Other examples of Effort Creep
Advances in technology can lead to massive changes in the ability of fishers to find and catch species. For example, the introduction of GPS into the Northern Prawn Fishery has conservatively estimated to make the trawling fleet 11% more effective at finding and catching banana prawns in the Gulf of Carpentaria.
Generally, banana prawns congregate in similar offshore regions each year, due to the combined effects of the timing and levels of rainfall, along with other parameters. Swapping of GPS discs between Skippers of past historical locations where banana prawn schools were caught effectively brought the level of efficiency of the any newcomer Skipper up to just below that of the old timers, in only a year or two. That equals ‘Effort Creep’.
The exact same process has occurred with the introduction of GPS\sounders\speedboats and such in the SE Qld offshore snapper fishery. The introduction and swapping of GPS discs allowed the learner Skippers to quickly arrive at the most likely locations\timings where congregations of snapper occur.
• So what does it all mean?
I have been around for a while on this planet and I am absolutely certain that catch rates of snapper have massively declined from when I was a lad. Are the stocks in strife? It would take a real gambler to bet that snapper stocks in SE Qld are healthy.
If you disagree with existing research estimates of the proportion of spawners (long-term) required to ensure sustainability, and discounted that value to even 10%, I suspect you would struggle to prove the case "that the populations of snapper in SE Qld are not presently under major stress".
If you can’t, then the alternatives seem to be reductions in bag limits. – Don Heales
( just made the font bigger to make it easier to read. Lucky_Phill...Moderator)
Last edited by Lucky_Phill; 13-04-2009 at 08:35 AM.
I can catch hundreds of the 25 to 30 cm ones, always have.
Maybe a better question would be where do they all go when they grow up, assuming they do grow up of course and don't end up in some trawler net.
As far as not being able to catch as many on soft plastics, I blame all you catch and release people for that, a big snapper is not going to fall that one more than a couple of times.
Dr Julian Peperell did a study on the 'good old days' of fishing in the Sydney area going right back to the First Fleet which puts some perspective on this. Using contempory reports it would seem there was never a super abundance of fish and never enough caught to be worth preserving them even though they had the means to do so (they would be consumed around the time of capture). Sure there were some occassional big hauls taken (using seine nets) but there were long periods of relative scarcity of fish (particularly in winter).
The snapper article conclusion of around 1% of virgin spawning biomass seems rather far fetched, as does his methodology. They would be well and truely in a state of collapse at this level! He han't considered that fish also wise up to angling methods and so anglers catches aren't a very good guide to abundance.
What concerns me about this is that most of the information used is some for of indirect measurement and makes an overly simple conclusion.
We do not nad have never had the faintest idea where all the snapper are, we only know that certain numbers have been caught in certain places at certain times........this is like an uncompleted dot to dot puzzel with more than half the dots missing and we are being told that they have a clear picture.
What do we know about the accuracy of those old reports, how were those figures gathered and what was the agenda at the time.
There have also been massive natural and man made changes in 200 years that may influence everthing that is going on in the water.
Consider only the splitting of stradbroke, at one time in the not too distant past ther was no jumpinpin bar and stradbroke was one single island that alone would have had a profound influence on current and nutrient flows comming out of the bay.
Flat rock under those conditions may have been an entirely different place.
Yes indeed there seems to be a complete and utter disregard of the ability of fish to learn. There seems to be a view that fish are completly stupid. It does not require tooo many smarts to look at a bait and see a big pointy metal thing in it and leave it alone.
When you consider that a good size snapper may be 20 years old that gives it plenty of time to wise up to not getting hooked.
When common bream are smart enough to strip the bait off a hook and not get hooked, you have to think about what a "snapper" which is in fact bream but a longer lived and possibly smater fish is capable of.
I do not think anybody would argue that just about every single creature is probably at much lower popuations than before white settlement, but do we hear of trying to restore virgin boimas levels of kangaroos, or koalas.
Oh who is this guy that wrote the letter anyway.
cheers
Its the details, those little details, that make the difference.
Reminds me of my post I did a few years ago called " Do Fish Learn?"
I've said in another post B4 too, if you were living in a street where the neighbours bcome noisy, they placed a toxic waste dump right next door that smells like a sewer and you had to drive 100K to get to the nearest supermarket, would you hang around for very long??
And we deduced that any "Biomass" baseline figures that DPI throw up on bed sheets with data projectors at our last Rocky Reef Fish public meeting don't stack up, and methods for gathering their base line data leave a lot to be desired, which is why we might see the introduction of catch cards and other methods that will give us real data to work with. But it still boils down to the same thing I started with - the fish have to be in the neighborhood, and be willing to take a bait or lure in the 1st place.
Scalem
I just thought itwas an interesting letter, not saying its to be given 100% credabillity, im saying that for me and other fishos i know the snapper have crashed numbers wise in the bay compared to 2 years ago, others i know who venture out off the gold coast find it a waste of time snapper wise, has nobody else notice snapper postings from the bay are nothing on what they were in 2007?.
Again even if there is a reduction in snapper postings on this forum from the bay.....that is not a scientific measure of population......then even if there are less snapper in the bay........there is no onformation on where they have gone and why.
perhaps it is a seasonal variation due to the drought, or water temperature. Has there been a a variation in the east coast current.
Has sand dredging for the new airport had an effect" are the big threadfins, sharks or something else eating them?..... the truth is we just do not know and there has been no concerted effort to find out.
What is very likley on the gold coast... there are two probable causes.....
significantly lower minimum size in NSW waters and those waters extending well up adjacent to the QLD coast line.
and
Known siltation of the near reefs on the gold coast. ( which many people blame on the tweed bar sand bypass)
So these two probalble causes will not and can not be addressed by any measures that the QLD government can legeslate.
There seems to be quite a lot known about snapper in port philip bay and surrounds ( read snapper secrets for a start), they pretty well know where they come from and where they go and there seems to be extensive research.
Up here there seems to be very little published and most of that that is published is hokus pokus sourced from indirect and unconfirmed sources and produced without leaving the DPI air conditioning.
cheers
Its the details, those little details, that make the difference.
Have to agree with you oldboot.
I went to a couple of the meetings and the figures quoted are theorical gesstimates. The only way to get real data is to do real life research and sampling.
It appears that in Qld, DPI&F is reluctant to do any thing like that.
Re the snading up of the Gold Coast inshore reefs, this was mentioned at the meetings and the DPI&F people just gave you back blank looks of disbelief.
It stands to reason that if the environment snapper like isn't there, then why would they hang around.
When you look at snapper management in Port Phillip Bay as against what passes for snapper mangement in Qld the disparity is mind bogling.
Luc
How many TRAWLERS were around in the late 1800s, early 1900s?
How many were working the area in 40s,50s and 60s?
What was the commercial TAC then?
Read the signature.
Rod
My dictionary defines green as ‘unripe, immature, undeveloped'. Perfect description.
Most political parties are seen as interested in what the voters think, the Greens are seen as thinking the community should be interested in what they think.
[quote=oldboot;999549]Again even if there is a reduction in snapper postings on this forum from the bay.....that is not a scientific measure of population
A lot of people who catch snapper in the bay dont bother posting
I know I don't post my catch in the bay or offshore
I agree the posts on this site are not a measure of whats happening with snapper stocks
It will be interesting to see if the stocks increase with the lack of trawling in the southern bay
"light gear big fish big fun"
OK , Ive done a bit of looking about.
and I have re read the letter as posted a couple of times.
Don Heales works for the the CSIRO division of marine and aptmospheric research at cleveland.
He seems to have his name on papers goimg back decades mostly on prawns.
So he is a scientist.
Now what real disapoints me.
This bloke is quite likley a fish scientist with some considerable knoweledge on the subject.........the fact that he makes the choice to write a condecentive letter to a fishing magazine whithout identifying himself as what he is.
It would be far more constructive for him to have written detailing what he does know and what reasearch has and is being conducted.
In essence he is looking down his nose at us and calling us ignorant by the tone of this letter.
This concerns me above all.
Now back to the letter.
The phrase "numerous estimates in fishing journals" is used....yeh "estimates" they don't know, they just stuck their finger in the air.
He admits that the concept of virgin biomass is dodgy.
He first states that Wellsby is the earliest figures that we can rely upon... then refeers to them as anecdotal.....so are they reliable or are they anecdotal.
This is important because that is the source figures all those fancy graps that the DPI scientists projected the massive decline back to.
He keeps harping on about effort creep and the sooo much superiour fishing ability of modern snapper fisherman and insisting on daylight fishing.
I believe this view is extreem particularly among recretional fishermen ( many of whom may be able to afford all the toys but couldn't catch a cold)
He also fails to mention the fact that the early catches were pristeen fish that did not know what a bait or a hook was, there certainly were not highly educated catch and release fish (include undersize).
He also uses two largely irrelivent commercial fishing examples... "atlantic cod" was almost exclusively fished as a mostly unregulated, large scale highly intensive, multi country, take all, trawl fishery where whole schools were scooped up by massive nets which killed everything that they caught, with no limits for decades.
The prawn fishery again a highly intensiive trawl fishery of a rigidly habitual very low inteligence spicies.
So the lessons earned from these two example are only of limited relivence.
He speaks of the spawning rates and persentages and what is theorised as being viable.
We are told by the DPI that every legal fish is of a size that has be able to spawn at least twice... However the NSW size limit is considerably smaller than ours.
So what is the point of bumping up our size limit. and this was viewed are a reasonable view by the DPI people at the meetings.
Not mentioned in this letter but definitely an issue.
In the south snapper are consiered ( some would say known) to be a highly mobile spicies that travels ( migrates perhaps) large distances ( documented cases of tagged fish) on the east coast current and under its own steam.
Apart from the reductions of commercial effort and changes of method that are
proposed or current and our "marine park zones"
As many have said before we need good research and quialty information not a condecentive attitude.
cheers
Otherwise all we will be doing is leaving snapper in the sea for the NSW fishermen to catch in larger volumes.
Its the details, those little details, that make the difference.
I agree about Port Phillip Bay snapper. I used to fish for them 20 years ago, anywhere between Frankston, Corio Bay and the Heads. We could spend whole seasons without catching a decent fish. But since then, the authorities have stopped or contained the scallop fishing (or 'raping') of the seafloor, and the japanese squid boats that used to fish outside the RIP. I dont have any recent experience, but by all accounts the snapper fishery in PPB is certainly better now than it was (at least) 20 years ago.Originally Posted by Luc
I have been giving this issue some thought recently and now feel it is time to ask the questions.
I think the questions need to be answered before we continue to put in place, ad-hok responses.
I know that some of the below questions already have answers... !!!!
1. At what stage ( age ) does a Snapper actually spawn ?
2. How many times can a Snapper spawn at the first stage / season ?
3. How many times does a Snapper spawn within the QLD size limts ? ( 35cms )
4. How fast / slow do Snapper grow ?
5. What is the survival rate of wild Snapper fingerlings / fry ?
6. Does the habitat / environment or the spawning areas have an impact on the spawning masses ? ( that is, will Snapper not spawn due to unfavourable conditions ? )
7. Do Snapper spawn after " Catch and Release " efforts by recreational anglers ?
8. What is the maximum bio-mass that any one area can sustain ?
9. Are recreational anglers controlling the bio-mass with their captures or are we placing it in a decline ?
10. Is Bio-Mass the best method of calculating the sustainibility of a species under current conditions ?
11. Is the current Bio-Mass a result of recreational angling, commercial fishing or environmental issues ?... Further... does anyone really know what the current Bio-Mass is ?
12. IF, as known ( DPI&F data ) that Snapper numbers being caught are down by recreational anglers, but tonnage is up, does that mean Bio-Mass is an outdated methodology and size and bag limitations imposed on recreational anglers are working ?
In relation to the above question, latest data ( for want of a better word ) from DPI&F states that legal numbers of rec caught Snapper in the Qld fishery are down from previous years by as much as 100,000 fish, BUT, the tonnage is way up. IE:- rec anglers are catching less fish but bigger specimens. !! This IMO throws the Bio-Mass methodology into chaos. Bio-Mass is a method based on tonnage........ not numbers. Which leads into the next question..
13. Should the scientific community base their methods of research on " Fish Numbers " as opposed to Bio-Mass ?
Let me explain my take... it maybe clutching at straws, but.....
Area " A " is 1 sq kilometer and contains 100 Snapper......
Area " B " is 1 sq kilometer and contains 500 Snapper...
Area " C " is 1 sq kilometer and contains 10,000 Snapper....
Which area is " Sustainable " ?
Area " A " has 100 fish weighing in at 10kgs..... ( 1,000kgs ) these are large adult fish and it is known that they feed on smaller fish etc. fall within the rec fishing size limits . It is also known that fish do not spawn after a certain age.......
Bio_Mass of Area " A " is 1,000kgs today, but what about tomorrow, next week next year ? Mortality rates, fishing etc will take a toll.
Area " B " has 500 fish weighing in at 2kgs.... ( 1,000kgs ). These fish are still well within their breeding lifespans, fall within the size limits for rec fishing, do not eat the smaller fish the fish in Area " A " eat....
Bio-Mass of Area "B" is 1,000kgs, but numbers are much more than Area "A".
Area " C" has 10,000 fish weighing in at .100kgs ( 1,000kgs ), these are pre-spawning size, feed on other plant and animal life than the above 2 and depend on a healthy environment to reach their spwaing age. They live in a nursery habitat.
Bio-Mass of Area "C" is 1,000kgs and numbers are again well above Areas " A & C ".
The Bio-Mass of each area is 1,000kgs... but numbers are totally different. Many analogies can be drawn from this example.
What area would you want to fish in ? A, B or C ?
I do know that a Bio-Mass is a conclusion of a Total Fishery that is in this case, Snapper from Mackay to the Qld Border and out to an area ( that IMO falls short ) depth measured at ? meters. That depth escapes me at the moment, but rest assured, Snapper numbers past this depth are huge.
I am not a scientist, a mathemathician or crystal ball gazer, but I feel that the methods of collecting data, producing outcomes and implimenting legislation is far from accurate.
Further, I am totally convinced that unsavoury environmental impacts are the most harmfull of all impacts on the Queensland fishery.
I further believe that historical natural events have impacts as do outdated commercial activities.
Certainly, recreational activities in SEQ in particular, have increased and methods to locate fish have escalated, but that does not directly relate to more fish being caught and in fact with the implimentation of recreational size limits, bag limits, closed seasons and protection zones, numbers of Snapper are down and IMO have fallen to within an acceptable Bio-Mass... IMO, the DPI&F have just about got it right and now we need the EPA to get off their asses and do their job.
The other issues of State to State compatibility in regulations needs to be addressed imediately.
All IMO only.
Phill
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Last edited by Lucky_Phill; 13-04-2009 at 09:34 AM.
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Alleycat, I remember a time not long ago when ever a fisho posted his catch of snapper or anything else, the green element within his site was hot on the trail, to condemn his act and publicly question his intelligents for carry out his or her favorite pastime and providing food for the family at the same time. There was also a big push of catch and release only and that has it merits, but we are all not the same and people. The posting of alot of members have drop I believe was due to this factor. I know this from a few menbers who have openly admitted of stopping or reducing their catch post due to the "grilling" that accompanied catch post.
Humility is not a weather condition.
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