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  1. #16

    Re: Why Nets Ruin Recreational Fishing

    Hard to argue with ignorance and inexperience.

    There is a very basic point that seems to not be registering. If a species of any kind, whether terrestrial or marine suffers mortality from a predator, then that species will utilise all cues - be they audible, chemical (olfactory) or visual to allow timely escape or avoidance of that predator. There are no exceptions to this very basic rule of predator - prey relationships. Any number of papers are in existence by any number of scientists which demonstrate conclusively that fish avoid predators in the manner described. Included in the research is the ability of fish to adopt predator avoidance at a scale appropriate to the threat ... which is known as the 'threat sensitive predator avoidance hypothesis'. What this means is that individual mortalities of other fish in a school will elicit low level avoidance strategies, but avoidance behaviour will increase as mortality rates increase. A net takes entire schools ....

    With regards pilchards spooking predator fish - why would the predator fish be spooked by their own prey? The predator fish must suffer a mortality by feeding on the pilchards before they would be spooked and that doesn't happen of course. This is a vastly different scenario to a net which does kill tailor, dart, bream, mullet, goldens, barra, threadies etc and which have every reason to avoid what is perceived by harvested species to be a predator that is far beyond any that they would encounter in a natural context.

    And yes, recreational anglers spook their target fish all the time. Most experienced anglers have experienced this. An example would be when a tuna is hooked out of a surface feeding school. It is often the case that the entire school will stop feeding at the very moment that one of their school is hooked. It is conventionally the case that the school will recommence feeding a short time later perhaps 100 metres away ... they don't flee the area, but only one of their school has been affected, not tonnes of them at a time. Snapper fishers have long held caught fish in the live well so as not to throw it back and spook the school. A tailor that is dropped (lost after hook up) will very regularly cause the entire school to leave the gutter and especially if the dropped fish is a mature fish. But they will probably be available in the next gutter along the beach until another fish is dropped in that gutter. Examples of recs spooking fish are endless and these are common scenarios that perhaps inexperienced anglers have no knowledge about and therefore can't appreciate what a net would do. I happen to have seen the behaviour of these fish around nets over a period of decades because I've had the opportunities to. Just because some of the posters here haven't any such experiences and put forth absurd assertions, is merely a demonstration of inexperience and a lack of knowledge associated with the fishery that they believe they know all about and animal ecology at its most basic.

  2. #17

    Re: Why Nets Ruin Recreational Fishing

    Unfortunately when it comes to arguing on the internet most cases are supported by nothing other then personnel experience, predujudice, and goals.
    Slider you seem very passionate about tackling nets in the area and that passion is commendable, however this is a massive industry that involves peoples lively hoods on both sides of the argument and unfortunately the only way to convince people one way or the other would be to utilise factual evedence, peer reviewed research and the biggist weapon of all being statistics.

    Its clear we all have varying knowledge and experence with netting and fish behaviour in general, personally i've only spent a little time up and down the beach but i've caught fish active netting occurring and in areas were it wasn't, but my experiences alone simply don't prove or disprove any argument i might care to make because there are simply too many factors in play.

    If you really are looking for a postive reception for you're claims rather then back and froth arguments amongst each other then i imagine the best way to do this would be to reference specific research in support, after all i'm sure there are any number of papers, things are well known and there are credible findings to support the removal of nets, but with out specific referencing these claims simply come across as blanket statements that won't convince others to get behind your cause.

    As i've said before i'm actually with you on banning or at least strictly controlling netting around the southeast coast but it needs to be for the right reasons and done in the right way, and convincing people of these aspects requires solid and irrefutable evidence.

  3. #18

    Re: Why Nets Ruin Recreational Fishing

    Slider - again, so much conjecture and confirmation bias, yet so little hard evidence to back it all up.

    You stated..."Any number of papers are in existence by any number of scientists" and
    "Definitely a major issue for fisheries managers Camhawk and yes there has been a couple of studies related to it that are now apparently only in the memory of a few scientists. I saw one such study on the 7.30 report in relation to Pacific salmon in the 90s. Any amount of research into audible and chemical alarm signalling that tells us that if the fish didn't do what I am saying they do, then it would be very surprising indeed. I have an email from a FQ fishery biologist that states in effect that this phenomenon is occurring and Tony Ham at FQ stated to me that FQ had noticed the phenomenon in relation to Australian Salmon. He now denies that, but he knows the deal."

    How about some hard evidence to back you up - 'any number of papers' is not really much of a support, is it?
    And 'only in the memory of a few scientists?' What...no published works on the subject?
    And it's a bit too convenient that, your FQ expert now denies ever admitting to what he purportedly did!

    You also stated..."the tailor would all of a sudden stop taking lures unexpectedly and could be seen swimming in only one direction (north or south) with other species and in a skittering manner which is highly unusual"

    Fancy that. In all my years of fishing, I believed that the predatory fish were simply moving on, to chase down a school that had also moved on!
    Indeed, once they'd caught up with the school again, they recommenced feeding.

    And finally..." I have also witnessed mac and longtail tuna as well as spotted mackerel flee beach seine nets containing only mullet - not just a few fish, but every school of macs and tuna in Laguna Bay and within seconds of the mullet within the net showing signs of panic and quite obviously emitting alarm vocalisations, and.
    "
    With regards pilchards spooking predator fish - why would the predator fish be spooked by their own prey? The predator fish must suffer a mortality by feeding on the pilchards before they would be spooked and that doesn't happen of course."

    I see that you've chosen not to address this blatant contradiction. I'd still be interested to know how predators can differentiate between netted and baitballed/harrassed prey - as on one hand, you state that predators flee netted mullet, (don't they like mullet?), but are attracted to distressed pilchards? (Yum...pilchards!). Which is it?
    And ..."every school of macs and tuna"? Seriously? Did you personally witness EVERY school fleeing? Across the breadth of Moreton Bay? Or was this just another assumption?

    Now don't get me wrong - I'm all for net-free areas as well. I've seen firsthand, the improvement in fish stocks in both PPB and Wagonga Inlet, (my stomping grounds for the past 40 years), since netting was phased out, and it's been a statistically substantial, (and documented) improvement.
    But...bold statements need to be backed with hard evidence, and we've yet to see any. So at this time, it's all conjecture and confirmation bias.
    "I've only ever seen black swans. Ergo, all swans are black."
    It also reminds me of a mate, years ago. He was trout fishing, and out of bait, rolled up a piece of his peanut butter sandwich, and caught a trout on it. Guess what he always took fishing with him from then on? And never caught another trout on? Did that stop him? No way. He was still convinced, but came up with other explanations for why his 'magic bait' no longer worked. Confirmation bias at work.

    And I'd still like to know why I was able to catch plenty of Snapper years ago in PPB, when active netters were within line of sight! And on my best day, caught and returned over 20 of them, whilst continuing to catch others! With active netting of pilchards and mullet less than 5kms away.

    As has been said by others, passion for a cause is admirable, but qualification and citations are required to make others believe..

    I'd like to believe you, but having experienced so many other erroneous conclusions drawn on other topics, on other forums, I've become quite the skeptic. Flaws in reasoning and assumptions are so very easy for the human mind to manufacture...that's why we have conspiracy theorists!

  4. #19

    Re: Why Nets Ruin Recreational Fishing

    Robfish - if fish can't discern between predator and prey cues then they're in a heap of trouble. Are the snapper in your region netted? Fish that aren't netted,wouldn't perceive a net as a predator and wouldn't flee.

    Tonight or over the weekend I'll put up a number of peer reviewed papers that support my case.

  5. #20

    Re: Why Nets Ruin Recreational Fishing

    Thank you. I look forwards to being proved wrong. And yes, the snapper were heavily netted, and longlined, in PPB at the time I was writing of, yet that didn't stop their feeding.
    And again, why would these predators flee a school of netted mullet, but be attracted to a school of harrassed pilchards?
    Sorry, it makes no sense.
    And you DO seem to be avoiding the points I've put forward.

  6. #21
    Ausfish Platinum Member Funchy's Avatar
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    Re: Why Nets Ruin Recreational Fishing

    Quote Originally Posted by Slider View Post
    Hard to argue with ignorance and inexperience.

    There is a very basic point that seems to not be registering. If a species of any kind, whether terrestrial or marine suffers mortality from a predator, then that species will utilise all cues - be they audible, chemical (olfactory) or visual to allow timely escape or avoidance of that predator. There are no exceptions to this very basic rule of predator - prey relationships. Any number of papers are in existence by any number of scientists which demonstrate conclusively that fish avoid predators in the manner described. Included in the research is the ability of fish to adopt predator avoidance at a scale appropriate to the threat ... which is known as the 'threat sensitive predator avoidance hypothesis'. What this means is that individual mortalities of other fish in a school will elicit low level avoidance strategies, but avoidance behaviour will increase as mortality rates increase. A net takes entire schools ....
    I don't think anybody is disputing that mullet, tailor etc would get spooked by a net and want to flee the IMMEDIATE area. I have an issue with a school of fish 22klms away for a commercial netter getting edgy, shutting down, fleeing. That's like saying a school of fish spooked at Woorim was the result of a netter at Tangalooma!!!

    Mate I'm all for supporting a cause through accurate data to support facts. In my line of work you get nowhere without out it. With out data you are just another person with an opinion. (Or as my old yankee boss said. "In God we trust, all others must bring data")
    Last edited by Funchy; 27-05-2016 at 05:23 AM. Reason: spelink and gramma
    Cheers

    Funchy
    Click "like this post" if ya reckon my dog is cute!!!!

    Three-fourths of the Earth's surface is water, and one-fourth is land. It is quite clear that the good Lord intended us to spend triple the amount of time fishing as taking care of the lawn. ~Chuck Clark

  7. #22

    Re: Why Nets Ruin Recreational Fishing

    Well Funchy, we've been promised peer-reviewed data and evidence, so we'll have to wait, won't we?
    Like you however, I'm extremely skeptical of distances quoted, as I have experience showing otherwise.

    However, my evidence is only anecdotal, as I haven't published any white papers on the topic!

  8. #23

    Re: Why Nets Ruin Recreational Fishing

    Think I saw it published once that burnt toast gives you cancer too!

  9. #24

    Re: Why Nets Ruin Recreational Fishing

    Slider I can see where the confusion is coming from. The mullet only net example spooking predator schools doesn't add up.

    But I can clearly get what you're saying regarding the distances fish could be spooked for. Sound travels much faster (4times) under water than in the air. If whales can communicate over thousands of miles of water then it's not exactly a long bow to draw that fish can hear audible distress signals from a net with tonnes of fish in it only 22kms away. I think Noelm's question? Regarding the school in the river is quite simple also. The water would largely need to be line of sight. So any land between the school in the net and the next school would block all or at least reduce the auditory distress signals getting to a school up inside the river. That school could be only 1km away and get much less of the noise than another school 15kms away that has no land in between.

    Dropping a single fish on line is rationally going to have far less effect on a school than 50-100 of the same fish smashed against each other in a net. I have also experienced many times the effect of dropping a tuna or mackerel and have the school shut down. You can catch two or three fish no problem with the school continuing to feed then you drop one half way through the fight and they are gone for a long time.

    It's logical also that baits and burley are going to counteract single distress signals from individual fish. I've seen fish also that hungry that you can do all the wrong things and they'll still feed. I bet though even under those circumstances that if half the school of tuna or macks were caught in a net it would shut them down very quickly.
    Democracy: Simply a system that allows the 51% to steal from the other 49%.

  10. #25

    Re: Why Nets Ruin Recreational Fishing

    I wonder if this article is where certain parties obtained their information?

    Awful lot of similarities...

    http://www.fishingworld.com.au/news/...of-the-iceberg

    I particularly like this extract -

    "These fish relay the message (secondary transfer) on to fish further afield and so on until fish that could be 60kms away have received the warning. All fish (other than baitfish that are too small for the mesh size of the nets and flathead which must go under, and some juvenile surf fish) that are in receipt of the warning and whose species have a history of being netted, swim away from the netted location on a slowly reducing scale with distance and alarm "pitch".

    So baitfish now have spatial reasoning capabilities, to work out the sizes of the meshes being used, and decide whether it poses a threat to them? And flatties know to hug the bottom to avoid nets? And they recall their mates being netted?
    Damn! Fish really are getting smarter! No wonder my catch rates are going down - and we all thought it was netters!

    Or maybe it's a very long bow that's being drawn?







  11. #26

    Re: Why Nets Ruin Recreational Fishing

    Lol Robfish, I am pretty sure that the op and the Author are the same person.

    not sure what you are referring to regarding spacial reasoning capabilities?
    Democracy: Simply a system that allows the 51% to steal from the other 49%.

  12. #27

    Re: Why Nets Ruin Recreational Fishing

    The OP and the author, one and the same? Hmm...could be!

    "All fish (other than baitfish that are too small for the mesh size of the nets and flathead which must go under, and some juvenile surf fish) that are in receipt of the warning and whose species have a history of being netted, swim away from the netted location"

    If you read the above, it clearly suggests that smaller baitfish will assess the size of the net being used, (obviously by ESP, as they are nowhere near the area), and ascertain whether it poses a threat to them. If so, they'll swim away. If not, they'll disregard it. AND they have the power to recall if they lost mates to a net in the past, and can choose to elude it this time.
    Bloody clever fish!


    "It's one thing to be thought a fool, and another to open your mouth, and remove all doubt."
    Abraham Lincoln.

  13. #28

    Re: Why Nets Ruin Recreational Fishing

    Quote Originally Posted by robfish 1 View Post
    The OP and the author, one and the same? Hmm...could be!

    "All fish (other than baitfish that are too small for the mesh size of the nets and flathead which must go under, and some juvenile surf fish) that are in receipt of the warning and whose species have a history of being netted, swim away from the netted location"

    If you read the above, it clearly suggests that smaller baitfish will assess the size of the net being used, (obviously by ESP, as they are nowhere near the area), and ascertain whether it poses a threat to them. If so, they'll swim away. If not, they'll disregard it. AND they have the power to recall if they lost mates to a net in the past, and can choose to elude it this time.
    Bloody clever fish!


    "It's one thing to be thought a fool, and another to open your mouth, and remove all doubt."
    Abraham Lincoln.
    That quote may be accurate in this case mate. Because it is not suggesting that at all. I read that as suggesting that baitfish that are too small for the mesh size don't get caught by nets. Because they don't get caught by nets they don't give off signals of warning and therefore don't leave the area.

    Natural learned behaviour is not a stretch also. How does a fish know that a shark is a danger but a whale is not? Why do fishing techniques become less effective over time? Why do Bass fishos keep fish in live wells they have no intention of keeping until they have finished fishing a spot? Obviously something is going on as far as communication is concerned.

    Why would fish that would normally exit a river and begin travelling north in the beach gutters all of a sudden begin to take large arcs out into the ocean straight after a net is shot? There has to be some reason for it. The most plausible explaination is that they are advising the nets. How can this happen without some sort of communication?

    We know whales communicate over thousands of kms. Japanese tuna fishos that net tonnes of tuna know that after a shot the tuna piss off so they blood the water to entice them to return. If Tuna do it, why is it so hard to comprehend that mullet and tailor do it also?
    Democracy: Simply a system that allows the 51% to steal from the other 49%.

  14. #29

    Re: Why Nets Ruin Recreational Fishing

    Quote Originally Posted by robfish 1 View Post
    Well Funchy, we've been promised peer-reviewed data and evidence, so we'll have to wait, won't we?
    Like you however, I'm extremely skeptical of distances quoted, as I have experience showing otherwise.

    However, my evidence is only anecdotal, as I haven't published any white papers on the topic!
    in a previous RFH submission by Lindsay.

    Fish, when trapped in a net, emit alarm ‘cues’ as a result of their panic (Myrberg 1981; Francis& Williams 1995; Smith 1992). Just as a terrestrial animal would release a cry of alarm whenbeing preyed upon, audible alarm vocalisations by sh, which can travel kilometres throughwater, warn conspeci cs and heterospeci cs of the same prey guild which has a history ofbeing exploited by beach seine nets, of the present danger. (Smith 1992) At the same timechemical ‘disturbance cues’ are emitted via a urinary expulsion when the sh become startledor alarmed, (Hazlett 1985; Kiesecker et al. 1995; Ferrari et al. 2008; Wisenden et al.1995just as a terrestrial animal would do in similar circumstances. Damage to the skin of thenetted sh resulting from contact with the net causes another chemical called schreckstoff tobe automatically released into the water which reliably informs receivers (conspeci cs andheterospeci cs) that conspeci c or heterospeci cs of the same prey guild have been predatedupon (netted). (Von Frisch 1938; Pfeiffer 1977; Smith 1992; Mirza & Chivers 2003; Pollocket al 2003; Brown et al. 2003)


    http://www.aph.gov.au/Parliamentary_...subs/sub26.pdf

    Looks to me like this bloke first saw "anecdotal" evidence and then watched the trend for years. Seems to me he's done his research and backed it up with peer reviewed papers. What you got?
    Democracy: Simply a system that allows the 51% to steal from the other 49%.

  15. #30

    Re: Why Nets Ruin Recreational Fishing

    Sorry mate, have to disagree. The important parts of the statement are as follows...
    "other than baitfish that are too small for the mesh size of the nets and that are in receipt of the warning "

    ,To my mind, this very clearly intimates fish that are not in the vicinity of the nets, but are further removed, (kilometers away?)will assess whether the nets are a danger for them, by working out the size of the mesh used, (spatial reasoning), and decide if they need to avoid them.
    It may well be a grammatical error, but the entire FW post is so full of supposition, conjecture, erroneous conclusions and confirmation bias, I wouldn't be at all surprised if that context was indeed intended.

    Just look at these excerpts from the article.

    "After all, I tend to hear about every school of fish that are netted on Teewah Beach"
    "It first became apparent in the 1980s that fish were becoming difficult to find following a haul of fish taken in a net."
    "It was obvious to me then that precisely the same thing must be occurring here"
    "More than a decade later and with countless hours of research and observation now under my belt"

    Seriously? There's one hell of a lot of supposition there, and without stooping to flights of fancy, I could answer each and every point with a more logical, rational answer than "the nets did it!"

    And don't forget the closing statement by the author...
    "I have been quite active over the years in trying to change netting practices here and at Fraser Island, as have many others. Quite obviously we have all been unsuccessful and are now pessimistic about ever seeing the day that Teewah Beach and Fraser Island are net free. "

    Well - no hidden agenda there!

    I agree that there are distress signals emitted by fish - to disagree would be foolish, but to accept the absurdities in the article? And did you happen to notice the distinct lack of professional citations to back up the statements?
    Who knows? Maybe I'm a just little more skeptical than others.

    And I'd still like to know why a fish in a net emits a different distress signal than one being harassed by predators? And how could such a signal have evolved in such a short time as nets have been used - and other species made aware of this, given that evolutionary traits normally take hundreds of thousands, if not millions, of years?
    Better to remain silent and be thought a fool than to speak and to remove all doubt.
    - Abraham Lincoln


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