Reply With QuoteGoing by what you would like to happen it would only be a negetive thing as theres more of a likely hood that only females would be taken defeating the purpose,its all work out on research females grow faster then males.
Heya's..
After recently being involved in a discussion about the taking of large (legal) flathead, some people were of the mindset that if it's legal, you're entitled to take it while others were saying you're an idiot for taking it. Saying that it's a big breeder and they're doing the wrong thing...
I was thinking about it and have asked a few people at what size they've seen flatty's roe up and some people have replied at quite a small size. (43cm)
My suggestion is to increase the minimum size from 40cm to 60/65/70cm and take off the maximum size limits. Now, the reason I say this is because if we all keep taking the sweet and juicy 40/50cm flatty's, they might not have reached spawning age/size yet, but if the minimum sizes were increased to say 65, then they would all be guaranteed to reach spawning age for a few seasons. While I know the fishing will be a bit shitty for a few years, but after that there would be plenty of flatties around for everyone.
Once the stock's are back up, fisheries could reduce the minimum size again back down to 40cm etc for a season or two and switch back and forward to manage the stocks better...
Anyway, I'm just after other peoples thoughts on this.
Going by what you would like to happen it would only be a negetive thing as theres more of a likely hood that only females would be taken defeating the purpose,its all work out on research females grow faster then males.
You obviously don't understand what I'm saying.. I'll try and put it differently...Originally Posted by chris69
At the moment, people catch flathead and take them BEFORE they reach spawning age, or after only having been through a single spawning season.. The "lucky few" that make it get to grow up and spawn... At a guess only 40% of flatty's make it to spawn several times, many only managing it once or twice before being taken. So it's 40% of the fish that's reproducing next years catch.. With the fisho numbers increasing every year, the numbers can't stay balanced for long.
Now, my solution: Min size = 70cm... Max = N/A
The first year this new law would be introduced we would only see the same numbers from the 40% of fish that made it from the previous year and laws... However, after those grow up, 100% of them reach spawning age, and will spawn for several seasons before reaching the legal size... So 100% of fish spawn at least once, if not several times.
A couple of years later the numbers would be off the charts because everything is reaching spawn age for several seasons.
Hope that makes it clearer for you.
I would rather take one fish at about 65cm than three at just legal, why remove bigger numbers of fish for a feed for the family?
Jack.
By taking one at 65cm (or new suggested legal size of 70) and throwing back the smaller ones, you're ensuring that every fish that is spawned makes it to spawning size/age for at least a few seasons. Instead of it barely making one season of spawning.
So while that big one you took won't breed anymore, the 4 you threw back are sure to out-number the egg's that that single one can produce in the same time period.
http://www.dpi.nsw.gov.au/research/a...tputs/2008/927
Summary
Dusky flathead is an important finfish species harvested by recreational and commercial fishers in NSW. This study identified that dusky flathead have an extended spawning period that peaks between October and March. Fish in spawning condition were caught only near the entrance of estuaries and in coastal waters immediately outside the entrance. It was determined that the length at which 50 percent of the estuarine population is reproductively mature was 32 cm total length for males and 57 cm total length for females. The corresponding estimated age at which 50 percent of the population is reproductively mature (A50) was 1.2 years for males and 4.5 years for females.
Females grew faster and attained a greater overall maximum length, weight and age than males. The largest observed female was 98.5cm (7.5 kg), and the oldest was estimated to be 16 years, whereas the largest male was 61.5cm (weight) and 11 years of age.
The current minimum legal length of 36 cm total length appears to protect approximately 5% of females and 75% of males. To provide greater protection to mature females to allow 50% of females to spawn at least once, would require an increase in the minimum legal length to 57 cm. Such an increase would virtually eliminate males from the fishery. This may not be beneficial to the long-term sustainability of the stock. Other factors, including the survival rates of released fish from recreational and commercial fishing gears, need to be considered in critiquing future management options.
And if the males turned to females after a certain age they would more productive.
Spindles
did that yesterday,kept a 72 but threw back a couple of 40s,only wanted one for a feed and at 72 that will feed the family.
Interesting topic.
An important unanswered part of the equation is:
"at what size does a flatty's relative survival rate increase?"
I'd think that as a fish gets bigger it is more likely to survive in terms of natural attrition, and even in terms of angling - bigger fish more likely to bust you off etc. I am sure that when they are little they are prey for almost everything and survival rates are low. When they are 40 cm, it probably improves, 50cm even better etc (obviously there is a peak at some point then it will decline again).
I'd say narrow the keeper-size pocket.
Min size 45 max size 65cm.
Protect more of the big breeding females which apparently produce many-many times more eggs than small breeders do (millions compared to hundreds of thousands), and get a higher proportion of the total population to a size where their survival rate improves (obviously I have no idea what that size is) hopefully giving a better population overall.
Why keep the big ones (over 70cm) anyway? Surely they aren't as tasty as the ones in the 45 - 60 range...no offence to anyone who does, that is a perfectly legal and legit decision.
Interesting document : "Reproduction and growth of Dusky Flathead..."
http://www.dpi.nsw.gov.au/research/a...tputs/2008/927
EDIT: just noticed that Pinhead had already put that reference in...it is an interesting read
Tim
I don't think survival rate has anything to do with it.
Bigger fish might survive, but they have to get big to start with.. And if we're taking all the 40+ ones, hardly any are getting up to that larger size AND breeding.
Always remember that our population is increasing at a very fast rate. (Just go out on a public holiday. lol)
I think the best thing is to ensure that we allow every fish to have a chance at spawning several times before being allowed to be taken... This alone would increase the fish stocks over a few short years. Yes it will take time before they get big enough to keep, but the numbers will just keep increasing.
Edit: It was determined that the length at which 50 percent of the estuarine population is reproductively mature was 32 cm total length for males and 57 cm total length for females.
So lets look at these numbers as an example. Males mature early on, great news!! But the important one is the females... 57cm...
So from 40 to 57cm is being taken BEFORE they get a chance to spawn even once. Now, if the minimum size was 65cm, every single flathead is going to reach spawning age/size AND spawn at least a couple of times.
Obviously the numbers are not 100% accurate, but for argument's sake lets say they are.
Edit 2: Bigger fish might survive better, but if there is less of them, what's the point of this argument ? Increase the overall fish stocks and the odds are well in the flatheads favor.
Hi
I have always thought the minimum size to take a flatty should be 45cm. Having concentrated fishing in the Caboolture river for many years and caught alot of good fish it always seemed a sin to take a small flatty even if it were legal. I had no reason to take anything that was just legal or below 50cm. I think about next years catch and how much bigger they might be. Not that I really know the growth rate of a flatty-- no importance really-- I just like to throw them back.
Saw some blokes one day at the ramp cleaning their catch and walked over to have a look. I was horrified and the size and remarked to the fact they were cleaning next years catch.ISome of the fish looked boarder line to me. I may not of got a nice remark but walked away thinking at least I was doing my bit for the fishery. Thats MO anyway.
I would like to see an increase in minimum size of at least 5 cm's. No particular choice of maximum length.
Ronnie
What references or studies have you used to backup your management plan. Backing up your claims is a big thing in the scientific community to be able to put forward a reliable plan. To hazard a guess i'd say that the rec sector total annual harvest would not be as large a figure as 40% although i'm unsure of recruitment rates for the dusky flathead.
To implement your size limits would be to spell a death sentence to female duskies. As per the NSW DPI figures quoted earlier, male duskies top out their growth at around 50cm, thereby meaning you would predominantly be harvesting females only and genetically stronger males
The limits in play account for the middle line between a male breeding age and a females age. sure the limits could be increased but not so much that we r not taking an even proportion of male and female specimens.
I think the nsw laws are madness, you can take 10 per person and you are allowed 1 per day over 75 cm!, so in effect they dont have a maximum size as how often do you catch a fish over 75cm, i catch lots of flathead, today i caught 20 i guess and i fish every weekend yet its been 2 years since i caught one over 75cm..
alleycat: Do you think that's because they don't get a chance to grow up before they're taken ??
Mattooty:
Let's say that the law is put into place that only 70cm and above dusky's can be taken...
In the first year: Every single fish caught would be released up to 70cm. Of those, whatever percentage of females that would have been taken, would now be free to grow up and spawn.
In the second year: Now, the fish that were caught last year that "normally" would have been kept had to be thrown back, and now those fish are growing to a spawning size and age.
In the third year: The fish from the first and second year, if they haven't reached spawning age/size yet, they are still being released...
Now, the few from before the law was introduced would now be getting up around the 70cm mark, while all would be breeding/spawning with possibly a few seasons already done.
In the fourth year: The fish from before the law, are now up to size and allowed to be taken. (But are spawning still until taken) Now the first year are spawning as well, and because they couldn't be taken to begin with, there is more of them breeding/spawning.
In the fifth year: The fish from before the law was introduced are well above 70cm and have been breeding for several years. The increased numbers from year 1 and 2 are both now up to breeding size and contributing to the stock levels.
In the sixth year: Again, fish that haven't been caught from before the law, as well as the "ever-increasing" numbers of the fish from the years where the law has been introduced are breeding as well...
I'm not going into the whole male/female debate... After a few years fisheries could reduce the size for a season and everyone could go nuts on all the 40-60cm males out there.
I hope that explains it better for you. As for your question regarding studies etc, there is no need for a study, this is just logic.
Hi drifty, thats what im thinking that they are caught before reaching that size, 20 years ago i used to catch quite a few flathead 60cm plus and today i would say that only one fish in a hundred or less that i catch is 65 cm or over, even 55cm is not very common anymore..
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