Snapper Stock Assessment-My thoughts

[Lovey80]

Ok ladies and gents I have taken a very short break from gobbing off about the Snapper issue to humor Andy and read the following link.

http://www.dpi.qld.gov.au/documents/Fisheries_SustainableFishing/StockAssessment-PinkSnapper-2006-Complete.pdf (http://www.dpi.qld.gov.au/documents/Fisheries_SustainableFishing/StockAssessment-PinkSnapper-2006-Complete.pdf)

After reading it, I am no more impressed than when I read the review and have no idea why anyone is holding any faith in it. So I will add my thoughts on it based around the Executive Summary and my own opinion of the model. Those 50 odd pages are a lot of my time I am never going to get back. The equations are a little complicated to understand but taken slowly, they are not the hieroglyphics they first appear.

Anyhow next post will be a long one so I'll finish this one by saying, I am not putting my own opinion out there to start an argument or to belittle anyone, they are my own thoughts so take them how you like. I will however give the little mission statement that the DPI-F has at the top of the Assessment. A mission that is exactly what they should be trying to do. You be the judge on the performance of either them or the gov't that funds them to attempt to achieve it.




The Department of Primary Industries and Fisheries (DPI&F) seeks to maximise the economic
potential of Queensland’s primary industries on a sustainable basis

[Lovey80]

Executive summary


Pink snapper (Pagrus auratus) support important recreational and commercial
fisheries in Queensland, particularly in the south-east region of the state. We compiled
historical landings data and biological parameter estimates and used an age structured
stock reduction analysis (SRA) model to assess the stock status.


Landings data indicated that recreational harvest exceeded commercial landings from
at least 1997 to 2002. Recreational landings from the RFISH estimates were around
500 t in 1997 and 1999 and declined to around 250 t in 2000 (national survey) and
2002 (RFISH estimate). Commercial landings from 1988 to 2004 ranged from about
70 t to 160 t. Maximum total landings from all sources increased from 200 t in 1946
to a peak of 678 t during 1997, then declined to about 400 t in 2004


We have already established that the methods used for data collection of the Recreational landings can amount to nothing more than a guess. The final statement would seem to show that the total landings for all sectors peaked in 1997 at 678t and then dramatically declined by over 40% to 400t in just 5 years. Anyone would think that we were in the middle of a North American style cod fishery collapse. But of course the vast majority of the "landings" were done by the Recreational Sector a figure that does not have any solid basis behind it. A few surveys? Please!


Of course we can't forget the December 2002 Size and Bag increase that would have a huge number of Squire being returned that previously would have been kept.


Catch per unit effort (CPUE) from the commercial fleet was relatively stable and
showed modest declines.


IMHO: CPUE from a sector that relies on fish landed is always going to give you a good gauge on where the fishery is at. At the end of the day no fish in the boat then they go broke.


Much stronger declines were evident in the Gold Coast
charter fleet.


I wonder why such a difference? One sector relies on results to put cash in their pocket (Commercial) and they seem to be able to do it fairly regularly. Stable CPUE and only modest declines? The other is a known group known to be lazy and do very little to put their customers on the fish, seeking to burn as little fuel as possible. I have heard this regularly on the street and just a flick through the reports on Ausfish tells a similar story. While this may be a generalisation and there may be a few that have been tarred unfairly with this brush but there is a very common trend. Add to this a known silting problem on some local reefs and you have a perfect reason to completely disregard the CPUE of Gold Coast Charter operators when attempting to do a SEQ wide Snapper Stock Assessment.


Age structure estimates from the commercial harvest in the mid-1990s
showed that most harvest occurred on fish aged 2–4, with few fish exceeding age 10
in the landings (snapper are known to reach at least 30 years of age on the east coast
of Australia and 60 years in New Zealand).


I know it's only early in the report but right there has me thinking an increase in the Minimum Legal Size (MLS) may have a role to play in increasing stocks. But we will leave it there for now.



The stochastic SRA model fit to the commercial CPUE data showed modest declines
in stock biomass, whereas the Gold Coast Charter CPUE and snapper age frequencies
indicated that the stock was heavily fished. There was substantial uncertainty in the
model parameter estimates fit to both CUE data sources, but the CPUE data provided
two alternate hypotheses of potential stock status (very low versus very highly fished).


Again, going back to a very important point, the SRA model based on Commercial CPUE shows modest declines in stock biomass. (Could the margin of error in the model in fact be large enough that on commercial data alone that there is in fact no decline in Biomass? Lets leave that one alone for now)?
Commercial are your litmus paper in any fishery, surely? They are as good as an expert at catching the target fish (if they don't they go broke) as you are going to get and they have significant investment in vessels that allow them to catch fish when mostly the other two sectors can't. Even on large charter boats if the winds are much over 15 and certainly over 20 knots the punters just don't show up.
And then we have our Gold Coast Charter operators and based on their CPUE we have a Stock that was heavily fished. Now, I am not sure about anyone else, but I surely didn't need some data collection and a fancy computer model to come up with an assumption that (on the Gold Coast areas that charter operators flog) Biomass is heavily fished? All you need to do is read the reports and ask a few of the unhappy punters that have been on GC Charters to find that out. The CPUE of the Commercial sector is your true Constant in all of this but alas there was "concerns" about hypersensitivity so?


We developed a Monte Carlo SRA model to fit the age structure data from the
commercial catch in the mid-1990s.


'Ok lads, our first attempt at using two of the same types of data from two different sectors gave us two completely different answers. They are too far apart to fit into our "model" Damn that comparing apples with apples stuff and try to figure out why there is such a difference. The GC Charter guys are telling us there is a real problem. So let's assume there is a problem and we will manipulate the Commercial Age Structure data (oranges) with a Monte Carlo Model until we can get a figure close to the GC Charter stuff. We'll just keep carving and painting until the orange looks like an Apple hey? How's that sound?' (for those that can't pick the sarcasm, tongue in cheek intended)


This model showed a picture similar to the Gold Coast charter CPUE of the stock status, predicting a 2004 population that was heavily fished and currently at 20–30% of the virgin condition with respect to total biomass.


'There we go lads we have done it, made the orange look like an apple to fit the modeland the suits that don't have a clue what we are talking about will eat it straight up. Don't worry about those Red Neck Recreational Anglers they'll bitch and whine and organise a 20 man protest that everyone will ignore and we'll paste this up as science.'


Get real! The only likely accurate part of this is that in fact the same 5-10-15 marks that are getting flogged on the Gold Coast are in all likelihood around the 20-30% of Virgin Biomass.


Due to concerns about hyperstability in the commercial CPUE data, we contend that
the SRA fit to the charter CPUE and age structure data was a more reliable indicator
of stock status than the SRA model fit to commercial CPUE data. However, the only
way to discriminate between these two stock status hypotheses would be to modify
the stock via anticipated higher future landings or a more restrictive minimum legal
size (MLS).


Due to concerns about the hyper-stability of Commercial CPUE data? Did I read that right? Why on this earth would there be a concern about hyper-stability of Commercial CPUE data? Is it because it told you something you didn't want to hear? Why not hyper-depletion of the GC Charter data? You know the guys that pushed this review in the first place? The guys that WANT restrictions on other sectors? You guys have got to be kidding me!


All of this on a stock figure of 2004, a year or so after a massive change in size and bag limits were implemented. The year after a size and bag increase would do what for your CPUE exactly?



We conducted future predictions of the stock status under the hypothesis that the stock
would require some management changes. Simulations suggested that the current
35cm MLS would maintain current low biomasses if landings did not exceed about
400t, but larger MLS regulations were necessary to initiate total biomass increases or
sustain higher landings. Both 45 cm and 50 cm MLSs caused increased stock biomass
in the future. A 40–60 cm slot limit showed modest increases in the population
trajectory and essentially acted as a 40 cm MLS because few fish were predicted to
survive past 60 cm. Yield per recruit modelling also indicated that the maximum yield
would occur at 45–50 cm MLS.


That whole paragraph sounds sensible, reasonable and achievable. It implies further management changes that affect the all three sectors in an equal way with regard to increasing the Biomass. It also achieves the DPI-F ultimate goal as underlined at the top "The Department of Primary Industries and Fisheries (DPI&F) seeks to maximise the economic potential of Queensland’s primary industries on a sustainable basis."


Maximum Economic Potential: That leaves a very broad spectrum to work within and although a fantastic broad statement of worth, it needs to be defined further.


If we agree that 400t is the aiming point for the whole fishery then I guess it is just a simple case of managing all three under that limit. That way we don't ruffle the feathers of the Commercial side because they MUST have their nice little 35cm Snapper for the market. I don't know about anyone else but the former DPI-F who are suppose manage the WHOLE fishery should be having a bigger vision than just 400t total landings. They really should be focusing on the "Maximizing Economic Potential" part of their job.


Lets get real here, I would be very surprised if the Commercial Charter industry started losing money if they were actually landing MORE tonnage of fish every year sustainably but yet the smallest one they weighed in was 40 or 45cm.


The paragraph also states that changes to MLS WILL "initiate total Biomass increases or sustain higher landings" so lets stop squashing this as a myth and lets argue to keep it on the table! A biomass increase and or higher landings is what we are ALL looking for here isn't it?


There is one point I would like to make about the paragraph though and the comments about the 40-60cm slot limit. While it may be possibly accurate (lets assume that to be true)that the minority of fish landed will be over 60cm and hence act as a 40cm MLS, there are some significant benefits to it. Even if it just allowed one fish over 60cm for the first 10 years and then 2 fish after that would provide huge benefits. Having more large thumping male and female fish in the breeding gene pool is essential to a continuing diversity of the breeding stock.


Don't ask me to quote the data because I can't, but I am aware that there is research that consistently taking fish over a certain size and leaving smaller and smaller breeding size fish in the gene pool has a genetic effect on the spawned population. In other words by a majority of fish being consistently spawned from less than 35cm fish we get a genetic make up that will see the eventual maximum size or growth rate of the population being reduced. That's second hand info from a friend that's in the game but it sonds plausible to me.


There is also a good read relating to WA Snapper that could also hold weight to this argument concerning the "Boom and Bust" years if it is a similar situation in QLD as I would expect and many will agree that rains and drought in QLD effect these boom and bust years.


http://www.fish.wa.gov.au/docs/pub/FactSheets/Fisheries%20Fact%20Sheet%205%20-%20Pink%20Snapper.pdf (http://www.fish.wa.gov.au/docs/pub/FactSheets/Fisheries%20Fact%20Sheet%205%20-%20Pink%20Snapper.pdf)


However, under the same scenario we found that the recruitment compensation
potential of the stock influenced the model predictions. If recruitment compensation is
high, the 35 cm MLS could sustain harvests of about 400 t. However, if the
recruitment compensation is low, a more restrictive regulation would be required to
sustain the fishery at current harvests (i.e. 45 cm MLS) or initiate biomass
improvements (50 cm MLS). Thus, results of this assessment suggest that a 45 cm
MLS would be a precautionary measure that would predict no further stock declines
under any scenario, and would result in modest stock increases if recruitment
compensation is high.


Again more evidence that MLS can be manipulate the stock levels. Being a slow growing fish maybe a jump to 45cm MLS over night would have a pretty big undesirable initial impact on all sectors. A good compromise would be initially a 40cm MLS with 1 fish over 60cm. That leaves potentially more big breeding fish in the pool and everyone doesn't take a massive hammering in the first 5 years for them to get to the 45cm MLS. If after 10 years the 45cm MLS is still deemed necessary then make it 45cm and 2 fish over 60cm. Judging by the sheer numbers of smaller Snapper about I highly doubt we have to worry about recruitment numbers now let alone giving them further time to breed AND in larger numbers and sizes.


Changing the MLS could increase loss of fish due to discard mortality. To address this
we developed a size and age structured model to evaluate the potential effects of this
mortality source. The model predicted that increases in MLS would increase stock
abundance unless discard mortality rates were very high (≥ 70%).


Would it be naive to suggest that making release weights mandatory in all boats that are targeting Snapper (and hence everyone just keeps one in the boat just incase they catch a Snapper so they don't get booked) would reduce the Discard Mortality rate to below the >70% figure? If there is education out there that the use of them is needed and people are forced to have them on board surely Recreational Anglers will use them. I know I certainly would and based on the attitude of the modern Recreational Angler, I think were a pretty responsible bunch over all that want to see the best for our resourse.


Future assessments for pink snapper would benefit from additional age structure data
for the recreational and commercial sectors. Monitoring how the age structure
changes in response to any changes in regulations will be important for future
assessments. The two CPUE sources indicated different stock trends and more
detailed spatial and effort data on the recreational and commercial snapper catch
would elucidate the potential for hyperstability. Such efforts would make the CPUE
data more valuable to future assessments.


Exactly what was the problem with the CPUE data supplied from the Commercial Sector?
"No catch statistics were collected between 1981 and 1987, but the Queensland Fisheries Management Authority introduced a compulsory commercial logbook system, CFISH, in 1988"



CPUE for Recreational Anglers is a total waste of time and money. The fact that the last sentence is in print is staggering. If you want total take, fine, that is an accurate figure that is theoretically obtainable with the right systems and structures (and money) But trying to use Recreational Effort as a guide to how many fish are left is like asking someone who never leaves their house how many cars they saw in a day from the front porch to decide how many new roads we need to build for all of SEQ. CPUE for Commercial is possibly valid. As stated earlier they have the means, expertise and experience to consistently put fish in the esky if they are there. Recreational Anglers are a totally different kettle of fish. The accurate CPUE for Recreational Anglers would make the fishery look like the demise of the North American Cod fishery times a million. Recreational Anglers want to catch Snapper sure. Some are pretty good at it too (90%/10% rule).
By all means record the Total Recreational Angler take, but don't bother trying to use it for CPUE and expect to get anything on the state of the fishery it's just a waste of time and money!


Now here is my Opinion about the model and I'll leave it at that. I don't intend to debate this point this is just my thoughts on it. Now I am no Scientist but I am far from a scholastic idiot.


The equations they have used are long, drawn out but seemingly extensive and thorough. Of course with anything of this nature there will have to be assumptions, there simply just isn't the available data to have every part of the equation correct 100%. So I'll have my say and let others believe what they like.


So the SRA is an age based model as stated at the top of page 10 under the Methods heading.


So the first Equation they state is (N) and that is trying to find the number of fish at each age. In that equation there is a little figure known as (Ut) which is the annual exploitation rate, taken from the landings each year (Ct). So later down they explain how they got to (Ct) the total landings. Underline and red is my added emphasis.


Total snapper landings (Ct) were estimated by using the combined catches from
several sources. For the period 1946–1982, we used data from the Queensland Fish
Board records. These records included commercial and recreational landings but were
not complete for either in any year. We used recreational charter boat catch records
from 1993 to 2002 (CFISH data, Queensland Department of Primary Industries),
estimates of total Queensland recreational landings (kg) from 1997, 1999 and 2002
(RFISH data, Queensland Department of Primary Industries) and a national survey in
2000 from which we obtained an estimate of recreational snapper landings for
Queensland. The RFISH and national surveys used an angler diary program and
random telephone survey to expand diary catches to the total number of anglers who
fished snapper in Queensland (RFISH 2001). Commercial landings were not collected
from 1982 to 1988 and were extrapolated using a linear model from time periods
before and after this period because we saw no reason for landings to have declined
during this period given trends in other aspects of the fishing industry. Recreational
landings from the RFISH surveys were extrapolated from existing estimates to 1946
by using the trend in the number of large vessel (> 6 m) registrations from 1986–2002
(obtained from Queensland Department of Transport), which averaged 4% per year
and was linear. Total annual landings were estimated by summing the measured and
extrapolated landings across the recreational, charter and commercial fisheries from
1946 to 2004. There is substantial uncertainty in the landings estimates and no way to
fully validate the assumptions made in our estimates. The SRA model was therefore
fitted to landings data that included the 95% confidence intervals around the RFISH
estimates and an additional +/- 50% of the total landings to assess how a large error in
the landings history would influence our results.


Now I am not sure about anyone else, but I am fairly sure that a large part of the "model" revolves around getting (Ct) right. If you are happy for them to use the parts underlined in Red to get their model right to tell us we are on the brink of collapse then that is up to you. If you want to give RFISH a 95% confidence then so be it. If you want to assume that the Recreational take has constantly gone up by 4% per year because the rego of > 6m vessels went up then so be it. Feel free to read down to page 21 and 22 where they try to justify comparing Oranges with Apples.


So for me regardless of what any reviewer says this model is rubbish! The data that went in is Rubbish so what can we expect to come out the other side???


Basically my thoughts on the matter haven't changed too much really:


If you want to implement a Mandatory Recreational Angler catch card and can find the cash to do it without stinging us more than you do already. Educate people on the reasons and how and crack on with it.
Put the 40cm MLS back on the table. Even a slot limit of 1 fish over 60 or 70cm if you want until the stocks are either "rebuilt" or the proper data collection shows you were wrong in the first place then 2 over 60 or 70cm.
Enforce release weights, any measure that can make an effect on the mortality of released fish has to be looked at.
Build those whining GC Charter operators some new artificial reefs to make up for the ones that silted up. More habitat = more fish.
Once your done building hundreds of meters of artificial reefs on the GC start on the rest of SEQ.

All in my humble opinion of course

[TheRealAndy]

Ok, so you dont beleive it. You have still missed much of it. PS, did you read the comments from the reviewer? Do some research on him and you will become more skeptical!!!

[thelump]

Well done on the effort you have put into that post Lovey80. Still not enough info to convince The Real Andy though:-? . I think you are on the money with your opinions and I am of the same ones. After all its there in black and white (and red and blue). How can we use information gathered way back when by the very few to determine the stocks of fish that are present at this moment?
Its rubbish and should be treated as such.
Cheers Jason

[Sevric]

I also add my congratulations for pulling it to pieces in layman's terms Loveday80 and placing it in an easier to understand format. Although my personal views differ in places, your over all presentation and dissection of the real problems are first class and worth the read.
I know some on this thread have put shit on some of my ideas but this is the sort of thing that need to be placed in front of all recreational anglers in Queensland and in fact all of Queensland. Your post here exposes the sly corruption and suspect science that fisheries are going to tar us all with. "It must be our fault; we are recreational anglers and have driven the Snapper population to near extinction for nothing other than our pleasure". The real facts need to be told to every one. It is not our fault although we can be part of a successful solution.
Your post has been appreciated.

[dayoo]

Good post Lovely80.

The original recommendations of the RRFF working group also included a requirement for release weights and a deflating needle with educational DVD on how to effectively use them.

Fisheries subsequently filed the recommendation in the too hard basket:-?

Offshore Artifical reefs for snapper was also discussed but dismissed as Fisheries seem to think that they would concentrate snapper and make them easier to catch thus putting more pressure on the biomass.

The other points you have raised I am in complete agreement with as they close to my option 5.

Cheers
Barry

[johnlikes2fish]

Have to say Lovey80 that your thoughts contain very little other than your uniformed opinions, which although interesting to read are based more on a vibe than any data/study. That is not a criticism its a fact.
I think we should pay for the right to fish and the money earnt should pay for research to ensure the fishery remains viable.
Accurate data is obviously extremely difficult to collect, so caution is always best in these situations, the key to regualtion is it should be flexible if through further study the fishery is found to be in better shape then limits etc should change.

[PinHead]

Have to say Lovey80 that your thoughts contain very little other than your uniformed opinions, which although interesting to read are based more on a vibe than any data/study. That is not a criticism its a fact.
I think we should pay for the right to fish and the money earnt should pay for research to ensure the fishery remains viable.
Accurate data is obviously extremely difficult to collect, so caution is always best in these situations, the key to regualtion is it should be flexible if through further study the fishery is found to be in better shape then limits etc should change.

I totally disagree with that statement in all forms.

based on that thinking how about we pay to use boats ramps..pay to park there..and the list goes on .

[johnlikes2fish]

We are all entitled to opinions Pinhead and my opinion is why should i pay for a boat ramp when I have no boat, why should my money that I pay to the council pay for your parking when you fish when that prime waterfront real estate could be adding to the public purse rather than being a cost to everyone.
If monies raised through fishing liicenses is used to secure fish stocks through study and whatever means are useful I see no problem with it.
If licensing fishing could provide 10 more fisheries inspectors and provide better understanding of fish stocks and habitats I am all for it.

[PinHead]

We are all entitled to opinions Pinhead and my opinion is why should i pay for a boat ramp when I have no boat, why should my money that I pay to the council pay for your parking when you fish when that prime waterfront real estate could be adding to the public purse rather than being a cost to everyone.
If monies raised through fishing liicenses is used to secure fish stocks through study and whatever means are useful I see no problem with it.
If licensing fishing could provide 10 more fisheries inspectors and provide better understanding of fish stocks and habitats I am all for it.

Perhaps you should be asking the Govt where our taxes and all their other income has been wasted long before you want to burden people with more taxes.
The idea of user pays is a total crock...the Govt has consolidated revenue to fund ALL issues necessary to operate the State.

[peterbo3]

We are all entitled to opinions Pinhead and my opinion is why should i pay for a boat ramp when I have no boat, why should my money that I pay to the council pay for your parking when you fish when that prime waterfront real estate could be adding to the public purse rather than being a cost to everyone.
If monies raised through fishing liicenses is used to secure fish stocks through study and whatever means are useful I see no problem with it.
If licensing fishing could provide 10 more fisheries inspectors and provide better understanding of fish stocks and habitats I am all for it.

John, those TEN extra inpectors are going to cost around $100K EACH per annum when wages, super, holiday pay,etc are taken into account. They always work in pairs so that is five new teams who will require new boats, trailers & tow vehicles. There is another $120K per team & the total is up to $1.6 million.
So to just break even @ $90 a licence, some 17700 boaties need to purchase that licence. Not going to be a significant amount left over for scientific research even if 35000 licences are sold. And I would doubt that 35000 people fish for snappa in the great southeast.
As you do not have a boat, you probably fish from the shore which, by your own definition, is primo waterfront land. Why not sell those beaches or foreshore land or jetties to boost the public purse.::)::)::)::)

Just sayin...............................

[johnlikes2fish]

50000 rec fishers at $20 each = 1 million dollars if they worked at 10 ramps waiting for people to return you wouldnt need a boat or even if they worked in pairs that is 5 ramps. And all I can say is i would be happy to pay $20 a year hell I would pay $50 to ensure that rules are followed and stocks arent over fished.
Pinhead as far as I am aware in NSW licensing fees are spent on fishing seems an easy way to go.
I wont enter into the debate about user pays as I am too busy paying for my drivers license, car rego, health insurance, water and rates..
I believe all people fishing should have a license not just boat owners.
Current NSW revenue is around $10,000,000 just enough left over for a little research if we can generate similar amounts and employ just 10 inspectors

[PinHead]

us trailer boat owners already pay via the PPV.
Here we go again about the NSW system..how many people are in NSW compared to Qld..how much coastline in NSW compared to QLd...that should answer your question immediately.

I am sure fisheries would not mind if you sent them a donation..personally I pay enough taxes thanks.

[Lovey80]

John, I did say that the post was just my opinion right? I didn't claim to be some sort of fisheries scientist did i?

For your own info I am on record as saying I would support a RFL. But no way in hell if it is anything like what NSW have. Mine and many others thoughts can be found here

http://www.ausfish.com.au/vforum/showthread.php?t=154653&highlight=fishing+licence

Cheers

Chris

[johnlikes2fish]

I have to be honest dont know how many rec fishos in NSW and my geography is shaky too so cant comment on coastline length or if fishermen utilise every inch of coastline or if they tend to congregate in certain areas around major population centres or if fisheries should concentrate their efforts in those areas or in spots where nobody goes or on state by state participation rates in fishing or boat ownership for that matter, but I am sure we get plenty tourists that bring a rod and they should also pay which would give a fairly good amout of revenue on top of what is collected from locals. The details of it could be discussed forever but my overall view is I dont think of it as a tax or a donation more like an investment and i would invest $20-50 a year to stop people excedding their limit and to provide more quality information on our fisheries to ensure they are sustainable.
Lovey like you I support the introduction of a RFL what model is used is moot at this point I used the NSW model to show the volume of revenue generated nothing more.

[TheRealAndy]

Gawd, you guys frustrate me!! FFS, look at that scientist who came up with walter stochastic sra model, Dr Carl Walters and also reviews the paper..

Look him up on wikipedia or something. Then look up the organisation he is involved with, the 'Sea Around Us' Project.... Something stinks... PEW...

I am stunned no one has picked up on this yet and used it to discredit the original paper.... BTW, even though PEW is in there, I still support the modelling used in the snapper assessment....(*puts on flame retardent suit).

[Big Deez]

Hi Chris
This is a quote from Walters in his "re-assessment" of the snapper fishery:


Moving to much larger size limits, e.g. 40 or even 50 cm minimum size, would be one way to maintain the current input control management approach without having to face the difficult decision analysis trade-off problem (between TAC and risk of collapse) discussed in the previous section. This is in fact the approach now being taken with groupers and snappers in Florida, and for some species (e.g. gag grouper, red snapper, red grouper, red drum) does appear to be resulting in stock rebuilding as predicted by Allen et al. However, a fairly serious negative side effect is appearing in those cases, namely increasing apparent recruitment rates leading to fishers being required to discard very high proportions (up to 90% or even 95%) of their total catches. Knowing that some substantial proportion of these discards will die, fishers are complaining ever more loudly about waste of fish, and are beginning to demand consideration of alternatives such as effort limits for recreational as well as commercial fishing.



Wouldn't this be a big problem for snapper if MLS was increased, especially in Moreton Bay? Also can you give us your version of what is meant by hyperstability?


Thanks

[honda900]

Gawd, you guys frustrate me!! FFS, look at that scientist who came up with walter stochastic sra model, Dr Carl Walters and also reviews the paper..

Look him up on wikipedia or something. Then look up the organisation he is involved with, the 'Sea Around Us' Project.... Something stinks... PEW...

I am stunned no one has picked up on this yet and used it to discredit the original paper.... BTW, even though PEW is in there, I still support the modelling used in the snapper assessment....(*puts on flame retardent suit).

Andy,

you just dont get it.. you can have the best, most complex mathmatical algorithim to work out any problem... however you put BS phone poll rubbish into the formula and what is the result.. GARBAGE..

As for the virgion BS biomass that has been calculated from 1945, these XXXXXXX can't figure a way to properly calculate the current stock levels and restort to using phone polls.... What makes you think that there was any science applied to the 1945 stuff, ie.. BigDEEZ and his mates with snorkals and a scoreboard..

Regards
HOnda.

[Big Deez]

Andy,

you just dont get it.. you can have the best, most complex mathmatical algorithim to work out any problem... however you put BS phone poll rubbish into the formula and what is the result.. GARBAGE..

As for the virgion BS biomass that has been calculated from 1945, these XXXXXXX can't figure a way to properly calculate the current stock levels and restort to using phone polls.... What makes you think that there was any science applied to the 1945 stuff, ie.. BigDEEZ and his mates with snorkals and a scoreboard..

Regards
HOnda.

Nah mate nothing to do with me - I wish I were smart enough, but no, nowhere near it. What port meeting will you be at Honda?

[PinHead]

Gawd, you guys frustrate me!! FFS, look at that scientist who came up with walter stochastic sra model, Dr Carl Walters and also reviews the paper..

Look him up on wikipedia or something. Then look up the organisation he is involved with, the 'Sea Around Us' Project.... Something stinks... PEW...

I am stunned no one has picked up on this yet and used it to discredit the original paper.... BTW, even though PEW is in there, I still support the modelling used in the snapper assessment....(*puts on flame retardent suit).

that was obvious Andy..but why bother raising it..I did a search on all of them as i did with the panel for the Green Zones and some of those on the green Zone panel are/were members of AMCS..so it is irrelevant..the Govt does not care.

[honda900]

Redlands..

As I was last time..

what meeting will you be at..

Regards
hOndda.

[TheRealAndy]

Andy,

you just dont get it.. you can have the best, most complex mathmatical algorithim to work out any problem... however you put BS phone poll rubbish into the formula and what is the result.. GARBAGE..

As for the virgion BS biomass that has been calculated from 1945, these XXXXXXX can't figure a way to properly calculate the current stock levels and restort to using phone polls.... What makes you think that there was any science applied to the 1945 stuff, ie.. BigDEEZ and his mates with snorkals and a scoreboard..

Regards
HOnda.

Actually, I do get it. And you have clearly not read/understood the assessment.

[TheRealAndy]

that was obvious Andy..but why bother raising it..I did a search on all of them as i did with the panel for the Green Zones and some of those on the green Zone panel are/were members of AMCS..so it is irrelevant..the Govt does not care.


There is a difference with this bloke though, and a lot of his work flies in the face of what our moronic australian PEW idiot stands for, and no doubt what PEW stands for in general. He aint interested in the green aspect, he is interested in viable fisheries management.

[Lovey80]

I guess though Andy when you play with the devil your going to have your reputation consistantly questioned for ever. Ie Using PEW cash for your projects.

As you say Walters is involved with The Sea Around Us Project started by a bloke called Daniel Pauly, Pauly is a member of the Board of Oceana, Oceana was set up by Pew. Walters and Pauly seem to be pretty close but who knows???

Hard to say who is who anymore. I bet large portions of world renowned marine biologists are only a few degrees of separation (if any) away from PEW charitable trust money.

Big Deez, it would NOT be a big problem if MLS change was introduced in Moreton bay. The bay is shallow water and there is no reason to suggest that large portions of returned fish will die if handled correctly in shallow water. If you actually fished MB you would know that those figures you quoted from the states are probably related as I think about 90-95% of Recreational caught Snapper are returned because they are undersize in the bay but I highly doubt a large portion are killed in the process. = MOOT Argument.

For deep water, release weights can also curb that returned fish mortality rate. I dare say that as long as the the stock was "rebuilding" the little emotional side effect of a few snapper off shore dieing would be of little concern. If Rec Anglers were that concerned about it on an emotional basis then they them selves have the option of changing to larger hook sizes to limit the catch of smaller fish that may be returned. Most Anglers will leave a location that has large numbers of banded undersize fish anyway because it is a waste of time and bait.

I can't believe that you would rubbish an option that is effectively rebuilding stock levels on an emotional basis. Feel free to stop resisting yourself from calling them Pink Sea Kittens.

NEXT!

Cheers

Chris

[Big Deez]

I guess though Andy when you play with the devil your going to have your reputation consistantly questioned for ever. Ie Using PEW cash for your projects.

As you say Walters is involved with The Sea Around Us Project started by a bloke called Daniel Pauly, Pauly is a member of the Board of Oceana, Oceana was set up by Pew. Walters and Pauly seem to be pretty close but who knows???

Hard to say who is who anymore. I bet large portions of world renowned marine biologists are only a few degrees of separation (if any) away from PEW charitable trust money.

Big Deez, it would NOT be a big problem if MLS change was introduced in Moreton bay. The bay is shallow water and there is no reason to suggest that large portions of returned fish will die if handled correctly in shallow water. If you actually fished MB you would know that those figures you quoted from the states are probably related as I think about 90-95% of Recreational caught Snapper are returned because they are undersize in the bay but I highly doubt a large portion are killed in the process. = MOOT Argument.

For deep water, release weights can also curb that returned fish mortality rate. I dare say that as long as the the stock was "rebuilding" the little emotional side effect of a few snapper off shore dieing would be of little concern. If Rec Anglers were that concerned about it on an emotional basis then they them selves have the option of changing to larger hook sizes to limit the catch of smaller fish that may be returned. Most Anglers will leave a location that has large numbers of banded undersize fish anyway because it is a waste of time and bait.

I can't believe that you would rubbish an option that is effectively rebuilding stock levels on an emotional basis. Feel free to stop resisting yourself from calling them Pink Sea Kittens.

NEXT!

Cheers

Chris

I don't think I rubbished anything especially on an emotional level. I just highlighted a section of Carl Waters' review. I'm not sure what I have ever said that makes you think i would think of snapper as pink sea kittens? Perhaps you have me confused with someone else?

This may be of some interest for you - post release survival of snapper in Port Phillip Bay. http://onlinelibrary.wiley.com/doi/10.1111/j.1365-2400.2009.00704.x/pdf

[johnlikes2fish]

A nice example or definitionof hyperstability
http://books.google.com.au/books?id=WnNVQKNwRsQC&pg=PA155&lpg=PA155&dq=hyperstability+example&source=bl&ots=wtFKmUF-BY&sig=8Zxpb6lF90Q9MX9jlmsHKa68R5w&hl=en&ei=ntouTcilD4OOuQPoutCqCQ&sa=X&oi=book_result&ct=result&resnum=3&ved=0CCMQ6AEwAg#v=onepage&q=hyperstability%20example&f=false
A scientist who writes a paper is fair game to all who read it so even if the scientist has associations with interest groups the methods and conclusions have to stand up.
A marine biologist who has associations with organisations that seek to ensure sustainability of marine systems, what next?

[Lovey80]

Oh I forgot to answer Big Deez question on what I though Hyperstability was.

Again I'll reiterate that I am not a scientist and If I have got this wrong then please let me know I have made the wrong assumptions. lol that may change my whole opinion of the assessment (but not the model).

Hyperstability with respect to this situation with Fisheries Snapper data is where the CPUE of the Commercial Snapper catch in this instance, showed relatively little effect on the biomass and very little drop in CPUE over the years.

The fear of the Scientists is that the data is HYPERSTABLE, meaning, that the data is showing little reduction but in fact there is sigificant reduction occuring. That being a situation completely opposite to Hyperdepletion where the CPUE is showing that fish are declining rapidly but the actual fact is not the case.

For example if only one type of lure was used to catch Barra in the stocked impoundments over years and years, the CPUE would show that the stocks were declining heavily and on the point of extinction. But we know that recruitment is stable or increasing all the time (because we are physically stocking them) and we know from these gun Barra dam anglers that catch methods become stale and need to be re-tuned all the time. So in this example there would be fantastic grounds to assume that any CPUE data collected over the last 10 years would be hyper depleted.

I tried to make my point known to this in giving my thoughts on what I would have been thinking at the time when the two different CPUE data models showed vastly different outcomes.

Imho.....There is very very good grounds for having concerns about the Gold Coast Charter data showing Hyperdepletion and NOT the Commercial Sector showing Hyperstability. I think I gave some fair reasons to assume this also, would you not agree?

Of course there is always a tendancy especially in this "Preserve" mindset era to assume that the data telling the worst scenario is closer to the mark and "remodel" other data to fit.

The truth is probably somewhere in the middle of the two but who knows?? Assumptions were made by fisheries but not detailed as to why. Thats why I was asking in the original post: Why was there concerns of Hyperstability with the Commercial catch? What led them to believe this? Am I right in assuming what I did?

Big Deez, how did I go?

A question of you though. What are your thoughts to my opinon that using Recreational CPUE is a complete waste of time and CPUE of Commerical is a far better litmus paper to guage a stocks status?

cheers

chris

[TheRealAndy]

Oh I forgot to answer Big Deez question on what I though Hyperstability was.

Again I'll reiterate that I am not a scientist and If I have got this wrong then please let me know I have made the wrong assumptions. lol that may change my whole opinion of the assessment (but not the model).

Hyperstability with respect to this situation with Fisheries Snapper data is where the CPUE of the Commercial Snapper catch in this instance, showed relatively little effect on the biomass and very little drop in CPUE over the years.

The fear of the Scientists is that the data is HYPERSTABLE, meaning, that the data is showing little reduction but in fact there is sigificant reduction occuring. That being a situation completely opposite to Hyperdepletion where the CPUE is showing that fish are declining rapidly but the actual fact is not the case.

For example if only one type of lure was used to catch Barra in the stocked impoundments over years and years, the CPUE would show that the stocks were declining heavily and on the point of extinction. But we know that recruitment is stable or increasing all the time (because we are physically stocking them) and we know from these gun Barra dam anglers that catch methods become stale and need to be re-tuned all the time. So in this example there would be fantastic grounds to assume that any CPUE data collected over the last 10 years would be hyper depleted.

I tried to make my point known to this in giving my thoughts on what I would have been thinking at the time when the two different CPUE data models showed vastly different outcomes.

Imho.....There is very very good grounds for having concerns about the Gold Coast Charter data showing Hyperdepletion and NOT the Commercial Sector showing Hyperstability. I think I gave some fair reasons to assume this also, would you not agree?

Of course there is always a tendancy especially in this "Preserve" mindset era to assume that the data telling the worst scenario is closer to the mark and "remodel" other data to fit.

The truth is probably somewhere in the middle of the two but who knows?? Assumptions were made by fisheries but not detailed as to why. Thats why I was asking in the original post: Why was there concerns of Hyperstability with the Commercial catch? What led them to believe this? Am I right in assuming what I did?

Big Deez, how did I go?

A question of you though. What are your thoughts to my opinon that using Recreational CPUE is a complete waste of time and CPUE of Commerical is a far better litmus paper to guage a stocks status?

cheers

chris

I would have to go read the paper again, but I though they provided refrences to this. When you read an academic paper, you need to also look at the references, because often critical explanations are overlooked under the assumption that the reader is, or can be made aware of the technical/academic detail.

I often get very annoyed with the crap that sunfish publishes, because they always come up with wierd stats and figures, but yet they never make reference to where they are getting this info. A paper is worthless unless you quote your sources of information.

[Lovey80]

Agreed Andy and in this day in age where papers get read mostly electronically it is easy just to wack in links to the references as they appear. That way if your not fluent in what they are banging on about you can simply click on the link read the reference and come back to it.

John,

A marine biologist who has associations with organisations that seek to ensure sustainability of marine systems, what next?

When you talk about the PEW environmental trust and similar organisations, your not talking about simply groups that "seek sustainability" These organisations are of the extreme fundamentalism that "seek" to make all harvesting of animals a thing of the past. Were not talking about sustainability issues with them (although they use that as their initial platform) were talking about them using huge amounts of money to influence political decisions that will eventually see us going down the road of complete vegetarianism and living like we were hundreds of years ago.

Good to know who is trying to do the best thing by you hey.

[Sullivan]

I'll never have a lot to say, but just got a couple of things.Up untill 25years ago anyone could take their fish to the co-op and sell,so should'nt that show as a decline in what went through the fishboard?.If ya put up a simple yes or no POLL on here (Do you think snapper stocks are in decline)would that be accurate info?Why do they need such a long closure?They tell us up here that the whole GBR only needs 2 or three 9 day closures.400t or 400.000 kilos,even if they were all 1kg fish(400.000 fish) a fish hatchery could produce that many fingerlings ten times over(japan breeds them ok).Not having to grow out the fish would mean it could be done in a average size industrial shed for less than they spent on survey paper,right on on the water no transport and rec anglers could pull up in their boat right at the front door with breeders,there is only ever going to be more people fishing as the popultion grows.Cheers Sully

[honda900]

Given your answer Andy,

I will assume you know where this came from.. just a differing view on the data provided.

· This stock assessment used a series of statistical analyses (generalised linear modelling, SALSA and SSRA population Models) to investigate to what extent, if any, the stock is overfished.
· Catch rates from the commercial sector were stable over time, appearing to indicate a low impact of fishing.
· Howerver, there are concerns that the commercial data were hyperstable (catch rates can remain stable while abundance is declining), and this concern is supported by charter data and two recreational data sources, which all showed consistent significant declines.
· Model uncertainties
· Although the best available data were used to determine the status of the stock, there was an inherent level of uncertainty associated with the data and model assumptions. Major levels of uncertainty exist in the key biological parameters of natural mortality and stock–recruitment, as well as in the fisheries data of the historical and recreational catches;
This one is brilliant..
· However, if there is a significant level of stochastic variation on top of a presumed deterministic stock-recruitment relationship (one level of stock size gives rise to a range of recruitment levels (then this interpretation is not the only one possible. A high proportion of smaller animals relative to larger ones could also be due to the appearance of numerous strong recruitment years. This confounding is particularly vexing because the possible interpretations are quite divergent – one of high fishing mortality and the other low fishing mortality and strong recruitment.

In order to remove this confounding it would be necessary to incorporate recruitment variation into the estimation process for the stock mode. One way to do this would be to estimate a recruitment ‘anomaly’ for each year of the fishery (for a concise summary of this topic and other approaches see Walters & Martell (2004, p. 96)). Preliminary runs of the model using this estimation approach ended up with very large recruitment anomalies estimated for the years 1993/94. The estimation process clearly preferred the strong recruitment interpretation to the high fishing mortality interpretation. The problem with this estimation is that we only had ‘snapshots’ of composition information (one in 1994/95 and one in 2006/07) to inform the model, not a time series. Time constraints prevented a detailed investigation of this issue; however, the following points are pertinent

Sensitivity to uncertain catch history

· The use of boat registration information and Fish Board records to construct historical changes in harvest has been criticised as a source of model bias. Likewise, there is uncertainty about the accuracy of recreational harvest estimates.

Regards
HOnda.

[caster226]

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[Lovey80]

LoL Caster some of us actually do hunt down and Kill Pink Sea Kittens.... I blame any loss of Biomass on global Warming.

[Lovey80]

Big Deez where did you go?

I read that link to the report on the PPB Snapper. Thanks for the link it was a long but interesting read.

Considering that QLD Anglers that hypothetically would be chasing Snapper larger than 40 or 45 cm, I highly doubt that there would be too much issue with them swallowing small long shank hooks designed for Whiting. Again I highly doubt that we have a need for concern for the survivability of shallow water returned snapper, especially considering most will be targeting them with a 4/0 - 5/0 Circle hook or a Soft plastic jig head.

Do you have an answer to my previous questions?

Cheers

Chris

[PinHead]

do any of you blokes arguing about this even fish for snapper because you come across as not having a clue for the most part. be nice if you could say what qualifies you to say the fisheries is wrong and you are right. seems more like a couple of keyboard heros just stirring the pot on a subject they dont really have any experience about.

and another keyboard hero rides into town..care to enlighten us with your credentials that makes you more entitled to an opinion on snapper stocks moreso than anyone else in Qld. Remember..these stocks are "owned" by all Queenslanders whether they fish or not.
Have you asked the Fisheries scientists if they fish for snapper..if they don't then solves it all doesn't it? Can the lot.

[johnlikes2fish]

Hi Caster I have fished most of my 43 years sometimes for Snapper (kayak and land based) I have a BSci (Env) which encompasses lots of statistical analysis, and 15 years professional experience, I hope this satisfies you.
I dont need to ask what you bring to the table Caster your previous post says it all.

[caster226]

comment removed

[PinHead]

40 years pl us of fishing both sides of the country from the beach bay cliffs and wide grounds. over 20 years this side of the big island now. fish with some gun snapper fishermen that a few blokes on here know go prety good that say exactly same thing. smaller fish. less fish and they are deeper for the most part. banks dont produce what they used to tempest doesnt produce what it did and the big catheredral fish are few and far bewteen now. numbers in the bay have crashed only the river fishes better than it used to. ask the pros how their catches are. ask the better charter skippers that have been in the game for more than a few years. the only idiots saying there isnt a problem is guys that cant fish or took up fishing a few years ago and are finally getting some sort of a clue about these fish.

sorry caster..you have only been over here for 20 years..your opinion does not count..you cannot comment without at least 30 years here..sorry.
You don't get it..EVERYONE has a say on this..all Queenslanders..not just those that have degrees or think they have fished with "gun" snapper fishermen..Everyone. and who started all this..some of your charter people!!!

No one is saying there isn't a problem..show us some real evidence first..are your gun fishos experts in environmental science and talking water samples to see if the water quality is the same as years back. Are the so called better charter operators seekign new grounds or have they just flogged the guts out of their favorite areas continually.

I just had a brilliant thought...if the snapper stocks are in so much peril then shut the lot for a year..pros, charter and recs..all out for 12 months...let's hear the GC charter blokes scream about that one...but I am probably just one of your idiots.

[PinHead]

reality is:
1. Quantifying if there is a problem. This has to be done as accurately as possible..and with fish that isn't easy. They live, die and move around. Water quality changes therefore they move to other areas of more favorable conditions. You would be flat out finding any in the Bay at the moment due to the water conditions.

2. Once you have established there is a problem, you then have to set in place measures to solve the problem with an end result being your aim.

3. You have to set in place periodoc checks to see if you are heading to your end aim..no point arriving in 10 years time and finding nothing has changed.

4. You have to have alternative measures in place in case your original solutions are not giving results based on periodic checks.

5. There has to be rewards at the end for those that have hepled achieve the result (if it is met).

[honda900]

Well said pinhead, couldnt agree more on all points..

regards
Honda.

[caster226]

comment removed

[Lovey80]

Who are you refering to? Who is trying to derail the process? And what process are you refering to? The one where the gov't makes a political decision to appease the greens and a lengthy, costly consultation process wastes everyones time for a result that is predetermined? Going by the logic of alarmists like you Pinhead should be the one calling for a Snapper collapse based on his Snapper catching ability :D

I guess it takes a bigger man than you to not blame other for their own short falls.