Why do blues die?
Printed From: The Fishing Website
Category: Saltwater Fishing
Forum Name: The Work-Up
Forum Description: Game fishing related topics here
URL: https://www.fishing.net.nz/forum/forum_posts.asp?TID=75713
Printed Date: 08 Jul 2026 at 1:13am
Topic: Why do blues die?
Posted By: obald
Subject: Why do blues die?
Date Posted: 13 Feb 2012 at 8:44am
|
I have for many years publicly expressed angst over the plight of any blue marlin coming within a hundred metres of a game boat in New Zealand waters. They all get acute transomitis and stainless steel poisoning and die. We should stop stringing up all these (in global terms) middleweight blues and release them all.
My stance is changing a little. I still would like to see most blue marlin that are hooked swim away from the boat but having had a little more up close and personal contact with these beasts I am now very sure that my black and white stance was wrong. I have been closely involved in the death of three blues in the last calendar year and now know that some (and I hope not all) of those poor buggers aimed at the centre of the earth from gantries up and down the land are not there because the angler wanted to kill them.
So why do blue marlin die? In other parts of the world much larger blues than the 170-220 kg models we speacialise in here routinely swim away from boats (or do they?) but in our waters the non evidence based impression I get is that a much higher proprtion of these don't get to swim away. Are our blues different? Unlikely I would think. Are we crap anglers and don't have the necessary skills to catch these very large fish quickly enough to allow them to swim off before they are totally stuffed? An uncomfortable truth I suspect. For most of us an encounter with a blue is a rare-ish event even if we are catching a fair number of their striped cousins. And they are very different animals in regard behaviour and sheer bulk.
The actual mode of death? Dunno and I haven't the time for a bit of proper internet research. I've heard tell of acute pericarditis which if you are a humanoid is definitely very bad for you. The bronzing is lactate in the skin and is a symptom and not a cause.
So, no finger pointing from me but a genuine interested enquiry from those who know more than I. ------------- Random musings on all sorts of things http://obaldnz.blogspot.com/" rel="nofollow - http://obaldnz.blogspot.com/ 
|
Replies:
Posted By: Bushpig
Date Posted: 13 Feb 2012 at 8:50am
|
Out of interest, what was th fight time on hat blue? Given the reports we were under the impression is was short. ------------- I would rather laugh with the Sinners, than cry with the Saints |
Posted By: A C
Date Posted: 13 Feb 2012 at 8:59am
|
They don't seen to die up in the tropics, I always thought that when they went deep our water was too cold for them and they just expire from extreme fatigue and cold ? ------------- Aye-Aye cloth eyes. |
Posted By: krow
Date Posted: 13 Feb 2012 at 9:11am
| I doubt it's crap anglers as it looks like a lot die fairly quickly. I'm failry sure that if I am graced with the option another one will die. |
Posted By: [email protected]
Date Posted: 13 Feb 2012 at 9:41am
|
Stress assoeciated with 27kg and 60 Kg Gear. I think we should all go down to 15KG...lol ------------- http://www.blackbillsportfishing.co.nz/" rel="nofollow"> 
|
Posted By: Wind Up
Date Posted: 13 Feb 2012 at 10:10am
| I have always assumed they built up lactic acid as oxygen in their blood stream is depleted during the fight and ultimately this killed them...However I am sure some guru out there can either confirm or rubbish this and if so provide the real reason. |
Posted By: Barrie
Date Posted: 13 Feb 2012 at 10:19am
sounds like a very good explanation to me. Colder temp may well cause the energy levels to be exhausted a lot quicker causing drowning |
A C wrote:Posted By: Bushpig
Date Posted: 13 Feb 2012 at 10:36am
|
Aren't the blues in the islands typically smaller than here? ------------- I would rather laugh with the Sinners, than cry with the Saints |
Posted By: Lethal
Date Posted: 13 Feb 2012 at 10:39am
|
that is what most old fishermen "Charter Boat Operators" say as well AC, some say let em run on a light drag, when they settle down up the drag and they just come straight in. i tried it in the Islands on a estimated 150kg Blue, it worked a treat less than 30mins, but in saying that, the one before this was similar size and took 1hr30mins, and still swum away no problem.... so maybe the it is the cold which is there down fall... ------------- Thanks for everything you did for us Eric. may you rest in peace, You were one of the real legends of NZ recreational fishing |
Posted By: A C
Date Posted: 13 Feb 2012 at 11:18am
|
Once they go through the thermocline in to the cold stuff with low oxygen levels possibly Eric ? ------------- Aye-Aye cloth eyes. |
Posted By: Jaapie
Date Posted: 13 Feb 2012 at 11:28am
|
Reading into this article, I believe a few factors have been touched on.
The lactic acid build up is one of the key factors.
Another thing to remember is the type of swimming muscles used and the conditions they are being used in. - fighting for it's life against a heavy drag setting.
When one looks at the physiology of muscles and muscle contraction it is a complex procedure. Secondly, mammals are warm blooded whereas fish are cold blooded (exceptions I know, but bear with me). Simplifying things down, we would effectively look at red muscles (tuna) versus white muscles (marlin) and warm blooded versus cold blooded to get a very big insight into the anatomy and physiology of what we are targeting.
Looking at red muscles they contract relatively slowly but require a lot of oxygen - why are tuna so tough fighting!!! Bulk and stamina play an important role.
On the other hand, white muscles are contracting faster, do not require the same amount of oxygen but the stamina is not quite there.
Blues (as with most fish) use white muscles as swimming muscles.
Yes, when you cut them up there are flanks or bands of red muscles along the caudal region and interspersed throughout the white meat, and this supplements those white muscles I'm on about.
Great for bursts of speed when feeding or trying to get away quickly, but not so good when stressed out over long periods.
Blues are super fast and use great amounts of energy and stamina in a short period of time and quite often the exertion is too much for the body and in particular the heart.
The cardio vascular system simply cannot cope and the heart literally explodes.
Someone touched on the subject of water temperature and this is indeed a pivotal factor to consider. In warmer temperatures (tropics - Fiji, Tonga) muscle contraction is stronger and dare I say it, faster for our cold blooded predators. However, stamina becomes a problem.
Conversely, warm blooded mammals are slower but have a better stamina ability.
Fighting something for hours on end and the build up of lactic acid in those tired muscles isn't going to do anyone any favours. Trying to release something close to the verge of death isn't going to be easy either.
So what is the key -
Personally, aggressive boat driving and good angles.
Using the gear properly and cutting down on fight times where possible.
Tag rather than gaffs
 Simplistic explanation, but hopefully helpful. ------------- "Only when the last tree has died, the last river has been poisoned and the last fish has been caught,will we realize that we cannot eat money" - 19th Century Indian Creed |
Posted By: biggear
Date Posted: 13 Feb 2012 at 11:31am
|
Id say it was because we killed it dead??? Or was it the sight of Boulder bent over the rod huffing and puffing? ------------- Dont let the grey hair fool you! |
Posted By: Martini Max
Date Posted: 13 Feb 2012 at 11:35am
|
A few years ago, I saw a clip of a researcher (well known, but I can't remember his name) dissecting a Blue Marlin caught during the HIBT. I remember one of his comments being that these Blues can accelerate to 50mph in one and a half times their body length. This was in explanation of the "shape" of the tail muscles, being that they surround the tail section radially, rather than longitudinally, and so giving this acceleration capability. Same for many fish I imagine -tunas etc. That this is sustainable for (for these fish) only short periods (how long is short?). Without any research, I suspect maybe they internally 'overheat' when sustaining long runs/jumps. Possibly as AC says, when they go deep, the temp. change of only a few degrees may be the reason - too rapid a change . Maybe "over exertion" results in the same as an overweight unfit fat bugger may suffer, when trying to sprint 200m. Or maybe they are just buggered and think 'to heck with it and kick off'. This was written much earlier this am, and finished just now. I think Jaapie has very well summed it up. Cheers. ------------- "I do nothing..I do it well.. I then move on to doing more of nothing" |
Posted By: TOSF
Date Posted: 13 Feb 2012 at 1:12pm
|
Jaapie, some good info there, cheers. This is a good thread for sure and already a few good points have been made. I am a kiwi and have fished central america now for the last 6 years, I have brought only one marlin on board in that time but sadly I have released a few fish that might not have made it and the thought of those fish is sad but it is the game we play, it is a blood sport. One thing I have noticed in the areas I fish now that a catch or a release is when the mate touches the leader only, this changes the whole game and gives the fish a better chance at surviving, it also promotes more aggressive driving , shorter fights and lighter leaders for higher hook up rates. Putting a tag in a fish or subduing a fish boat side for a photo is limiting the fishes chances of recovery for sure. This is not a dig at us kiwis but it seems that in NZ that a fish is only caught when it has a tag in it? or brought on board? this way of thinking is only doing the fish more damage, interesting reading this forum with the way people analyze what is caught and what is not, this is not a dig at the way we class a caught fish but our way of thinking is surly killing a few fish each year that could have lived just because a captain or angler was not sure if he "Caught the Fish" so to make sure drag it beside the boat just so his mate can not say he did not catch it and over analyze it at the bar that night. A lot of the touch the leader thing has come from tournaments with circle hooks and simplifying the rules. Colder water may have something to do with it? using a lot more energy? be good to learn more about this more. Interesting though I know one boat that has put satellite tags hundreds of Marlins, they say the worst survival rate came from Blacks? I personally have had more issues with blacks but that may be due to live baiting. It is interesting how the "common" tournament rules of each country then reflect back to each countries way of interrupting a catch or release. Please do not take this the wrong way, I do not mind killing the odd fish and even more so for prize money, but this does make you think for day to day fishing how we can release fish quicker. Be good to learn more about the Blue and how we can look after an amazing fish and release them healthy. I sure there will be some great info coming out of this thread for sure with the amount of experienced people that post here. Just my 5 cents worth. ------------- http://www.facebook.com/TonyOrtonSportFishingOffshoreAdventures www.offshoreadventures.net http://www.legasea.co.nz" rel="nofollow"> 
|
Posted By: alan syme
Date Posted: 13 Feb 2012 at 1:16pm
|
Posted By: Peter Pakula
Date Posted: 13 Feb 2012 at 1:23pm
| Blues don't die in the fight, they are killed by the tactics used to fight them. Hard to take eh! The ingrained traditional 'fear fight' will pretty much kill just about every blue you hook regardless of where in the world you are. |
Posted By: SumDumBum
Date Posted: 13 Feb 2012 at 1:48pm
|
Jaapie offers good information and experience , I agree with it all . But added to jaapies information I would also factor in the the NZ Thermocline , which would be a lot harsher that in warmer tropical areas.
How does that work..... ??? The Colder the water , the less Oxygen it Holds...... add that to a desperate fight for life with a sounding fish.....and maybe they just suffocate down there....
It is always a sounding fish that dies.... I havent heard tell of one flaking out on the surface...
Thats My theory anyway.... and of course I could be hopelessly off the mark. ------------- Si Vis Pacem para Bellum |
Posted By: Barrie
Date Posted: 13 Feb 2012 at 1:51pm
could you take this further please Peter. why is it the fight and what do you suggest to improve things? Not that I have cought a Blue but I would have thought that the fight would be the same? Is it a lighter drag or heavier line? |
Posted By: herby
Date Posted: 13 Feb 2012 at 2:04pm
| Colder water holds more oxygen SumDumBum |
Posted By: Jaapie
Date Posted: 13 Feb 2012 at 2:36pm
That is a very good point you make there. The thermoclines are quite variable depth wise depending on where you are in the world. Evidence suggests that in the tropics there is a semi-permanent thermocline and variable thermocline in temperate regions. NZ falls nicely within this sector (sub 23 degrees latitude) Below the thermocline the water is quite cold (it can vary upwards of 12 degrees from surface temperatures if I remember correctly) and evidence suggests it becomes anaerobic and more so the deeper one goes. Applying that to the metabolism of the cells in the fishes body, they are struggling in an environment without oxygen (more accurately decreased oxygen). For the boffs, anaerobic glycolysis (sorry guys) leading to the lactic acid buildup argument all over again. ------------- "Only when the last tree has died, the last river has been poisoned and the last fish has been caught,will we realize that we cannot eat money" - 19th Century Indian Creed |
Posted By: Jaapie
Date Posted: 13 Feb 2012 at 2:39pm
I think what he is referring to in this instance Herby is the factor of what is below the thermocline.
I posted something up just before this that may help explain some of it.
Deals with lack of oxygen with depth (colder water columns = colder water = less oxygen). ------------- "Only when the last tree has died, the last river has been poisoned and the last fish has been caught,will we realize that we cannot eat money" - 19th Century Indian Creed |
Posted By: Mashies
Date Posted: 13 Feb 2012 at 2:48pm
|
I certainly have pretty limited experience on blues but the one I have been involved with was in Madeira Portugal with the very experienced skipper Peter Bristow. Despite fishing with heavy tackle (60kg) the drag pressure was generally kept at about 6-8kg and only increased on a few occasions as the fish tired and got closer to the boat. I'm not sure if this was designed to ensure there was no unnecessary pressure on the gear (particularly with a lot of line in the water) or to ensure the least possible stress on the fish but on this occasion it certainly seemed to work as the fish was landed in 40mins (estimated 900lb!!) and was released in good condition after a few moments towing the fish in a snood (device for holding the marlin by the bill).
Would love to know if the tactic of reducing drag pressure while the fish is running early really does help releasing the fish in good condition??? |
Posted By: Peter Pakula
Date Posted: 13 Feb 2012 at 3:21pm
|
Oh, dear I knew I should have stayed out of this. High end predators are designed to travel through thermoclines at high speed. They can feed anywhere in water column at ease. Tracking proved that long ago. Below are 3 images, 1 with a belly in the line, 2 photos with the line in direct line with the fish.    The belly is with the drag set at strike, the ones with direct line have drags set at around 40 or 50% As you can see the belly in the line means the fish is pulling the line / drag, much like a horse pulling a cart, do that to a thoroughbred racehorse and it will go a little way, hyperventilate and drop dead, it needs lots of oxygen in it's blood stream and designed to get that at speed. Marlin, especially blues are thoroughbred sprinters, not draught horses, they need to be able to move, on the tight leash with pressure on the side they can trot around the oval forever and they won't die. Dragging line like a cart, slows them down and the suffocate. So
step 1 in saving a blue: don't go below strike, in fact go up slightly in drag 40% will do Step 2 will come later... maybe :) |
Posted By: Moocha
Date Posted: 13 Feb 2012 at 3:55pm
Learn something new every day 
|
Posted By: Peter Pakula
Date Posted: 13 Feb 2012 at 4:37pm
|
Step 2: Stay downcurrent of the fish with the angle of line shallower than 45 degrees to the surface. If you keep drag pressure of 33% or over the fish can't dive. If the fish gets close to the boat keep the the drag on and move down current and the fish will come to the surace. The design of the fish, the way it's built means it can't do anything else. The skippere should watch his GPS and work out the direction of trhe current and speed before you hook up. If you are upcurrent of the fish or have a shalloer angle ie fighting the fish draight up and down, the fish will dive, once again it's the design of the fish, the way it's built means it can't do anything else. Very simple instructions = no dead blues, stripes or blacks and far fewer wrapped up fish.
|
Posted By: A C
Date Posted: 13 Feb 2012 at 5:37pm
|
So - why don't Striped Marlin tend to die, is it because of different musccle tissue ( red or white ) ?. I've known them to dive well down but not to 300m. ------------- Aye-Aye cloth eyes. |
Posted By: Boulder
Date Posted: 13 Feb 2012 at 5:44pm
|
Hmmm hearing what you say PP but my fish died on reaching the trace and the drag was never below strike and the fish did bugger all really so not sure why or how it was stressed. Lots of fast backing up in ****ty conditions that soaked my matrimonial tackle completly
------------- http://www.boulderguiding.co.nz">  http://www.boulderguiding.co.nz">www.boulderguiding.co.nz |
Posted By: A C
Date Posted: 13 Feb 2012 at 5:49pm
------------- Aye-Aye cloth eyes. |
Posted By: KARP
Date Posted: 13 Feb 2012 at 6:34pm
|
We had a fish take short corner and peel the 80w.. managed to turn and chase just in time.(another engine was mentioned) by the time we had line back ,we were locked on bottom at 400m wouldnt move a inch straight down..this fish dived to bottom straight away,because it bottom locked we presume it was a blue marlin or was it a big yellow fin?
Heart attack from stress my answer. ------------- www.femmefatale.co.nz |
Posted By: Peter Pakula
Date Posted: 13 Feb 2012 at 6:40pm
| The Backing up pretty much means the fish was upcurrent. Check my Blue marlin vids, all endplay has boat going forwards, downcurrent, not backwards unless the fish is stuffed on the surface and close. No dead fish in over 20 years with the system.... easy, it works. Not saying other systems don't, but the one I've described is the easiest I know of. |
Posted By: Tagit
Date Posted: 13 Feb 2012 at 6:53pm
| Can't and won't disagree with you Peter, because I don't know the answer, but a Blue that died on us last year (a very large fish) ran off 700 - 800m in pretty much a continuous run and then dropped dead pretty much instantly from what we could work out. We lost that much line with the boat charging hard backwards in pursuit, so trying to move in any other direction to get up current etc would have seen us spooled. Like many Blues the fish ran one way first and then changed direction to go on it's long run. I am struggling to work out how you get up current of a fish behaving like this and not get spooled. Any tips? |
Posted By: mangre 2
Date Posted: 13 Feb 2012 at 7:07pm
|
We have had one striped marlin die, only one though and it came up covered in mud. shallow water 100m so got it up.
Better to get thenm in as fast as possible, before they sink into the abyss.
The boat I fish on has a graple hook to send down the line if it happens.
But boulders fish died of fright
------------- Beautiful is better than ugly, Explicit is better than implicit, Simple is better than complex, Complex is better than complicated. http://oceanmobilemap.blogspot.co.nz/ |
Posted By: Peter Pakula
Date Posted: 13 Feb 2012 at 8:35pm
|
The Panic of a Blue bite is pretty scarey. Guys freak almost as much as the fish, but I've never seen Blue end up 700 or 800 yards away from the boat in a run (check on your GPS just how far that is), but have seen lots of guys dump that much and more in the water during a Blue Marlin run. That's why we go up and not down in drag on the fish's run to stay in contact with it. I do know how absurd that sounds to most, but there's no stretch in the line and you have direct contact and when it settles down you know where it is, and once it settles down there's pressure on it right away and that helps control it pretty easily. I know this all sounds insane to most which is why most do what most do and that's why so many blues will continue to die in the fight and why all the theories will circulate most probably for another 20 years, and one of those theories will sound just fine to help you deal with it. I do have full length fights on gopro footage if anyone is interested. |
Posted By: obald
Date Posted: 13 Feb 2012 at 9:19pm
Coming along nicely It's 0315 in Florida, so a little while to wait.............. ------------- Random musings on all sorts of things http://obaldnz.blogspot.com/" rel="nofollow - http://obaldnz.blogspot.com/
|
Posted By: Bushpig
Date Posted: 13 Feb 2012 at 9:21pm
|
We hooked a big blue on our second year of fishing. Been new it came within 50 meters of spooling up on the first run before we had cleared the gear, we had easy 600 meters of line on the reel, we were lucky to get it all back on only to lose it at 25 metres from the boat. we were fishing 24kg The drag was at strike and it had been checked ------------- I would rather laugh with the Sinners, than cry with the Saints |
Posted By: Marligator
Date Posted: 13 Feb 2012 at 10:41pm
| Tagit, if I am reading Peter's step 2 correctly you actually want to be down current of the fish not up current, is that correct? |
Posted By: Lethal
Date Posted: 13 Feb 2012 at 11:57pm
|
and if there is no current?????
------------- Thanks for everything you did for us Eric. may you rest in peace, You were one of the real legends of NZ recreational fishing |
Posted By: KARP
Date Posted: 14 Feb 2012 at 12:24am
|
There is usually more wind than current,half the time you dont know which way the current is going anyway ..so fish to be to windward. works for me. ------------- www.femmefatale.co.nz |
Posted By: Peter Pakula
Date Posted: 14 Feb 2012 at 12:56am
|
Lethal, generally where there's no current there's no fish, or very few. You don't need much current for the system to work Fish don't swim in the wind, that's bird stuff. Try and stay with the genus we're talking about :) Learn to read the GPS and wave action to work out which way the current is going. You can tell by looking at your wake. Karp if your way gets healthy blues released then that's great. Yes Marl, you stay downcurrent of the fish. |
Posted By: mangre 2
Date Posted: 14 Feb 2012 at 1:14am
|
if you hook a blue between BOI and Whangaroa tomorow make sure the fish is on the whangaroa side of the boat. ------------- Beautiful is better than ugly, Explicit is better than implicit, Simple is better than complex, Complex is better than complicated. http://oceanmobilemap.blogspot.co.nz/ |
Posted By: Peter Pakula
Date Posted: 14 Feb 2012 at 1:24am
|
Not neccessarily, most of the fish are in eddies, mainly the leading edge where the current is likely going west to east, not as assumed north to south. The eddy may be going south, but not the current, as per this image: http://pakula.com.au/images/stories/BTL_Media/0101_Ocean_Systems/0101%20SST%2006.gif - http://pakula.com.au/images/stories/BTL_Media/0101_Ocean_Systems/0101%20SST%2006.gif I'll leave you with those thoughts to ponder. I'm off on another lecture tour. I think you can get maps that show current stregth and direction for NZ.  |
Posted By: Roddy
Date Posted: 14 Feb 2012 at 2:11am
|
** arrives at bank-side to see fish moving and many footprints by the muddy water.** ** sets up a rod for ledgering with a blob of dough as a bite indicator and opens chair, relaxing in the sun** ** looking into swim, sees something glinting murkily on bottom, so fishes it out with a bank-stick** **tis an empty tin, with a label - ARKWRIGHT's FINEST RUDD GROUNDBAIT** **packs up gear in a hurry, throwing unwanted bait into a water and leaving a wellie behind stuck in the mud at water's edge, rushes to car and drives away at high speed** ------------- http://www.legendlures.com - www.legendlures.com 
|
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 5:28am
|
Blue marlin they do die maybe not on everyone,, as peter pakula has written about his style..if you do want to catch and release a blue marlin without killing it ....3 pointers to do it i reckon,,this is the mongrel dogs opinon..so what ever you decide
1..when you get a strike dont drive foward away from your fish for another 3 minutes and lose 300meters of line!
2..if the fish is up on top drive to the fish in a straight line with your boat bow first....doesnt matter how much drag..less the better
3..know if you get closer to the fish...come back up on your drag and stop her from going deep!!
|
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 6:25am
| i reckon the more agressive you are on the hook up in the earlier stages of the fight..with your boat to stay closer to the fish is the better....for the release and lesser the chance of a D.o.A..... |
Posted By: mangre 2
Date Posted: 14 Feb 2012 at 7:40am
|
makes perfect sense.
peter
roddy
mongrel dog, to complicated lol ------------- Beautiful is better than ugly, Explicit is better than implicit, Simple is better than complex, Complex is better than complicated. http://oceanmobilemap.blogspot.co.nz/ |
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 8:17am
| i exspected that from you mangre 2 you mongrel!!!!!!,,haha lol |
Posted By: stef da maori
Date Posted: 14 Feb 2012 at 8:35am
------------- Tama tu, tama ora. Tama moe, tama mate.Maranga mai, me hiika tatou i nga wa katoa. |
Posted By: Rockstar from Mars
Date Posted: 14 Feb 2012 at 9:06am
|
I have heard the blue marlin is not the tastiest of fish, Wondering when the fish dies what do you do with that much fish? ------------- Winning..... |
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 9:20am
| give it to the locals......... |
Posted By: Roddy
Date Posted: 14 Feb 2012 at 10:12am
|
Rockstar, give it to someone who knows how to cook fish and it is perfectly fine. Almost everyone I know cooks it wrong the first time and then gives up, saying it is horrible. It's actually pretty good smoked too. ------------- http://www.legendlures.com - www.legendlures.com
|
Posted By: SumDumBum
Date Posted: 14 Feb 2012 at 11:39am
|
Herby...
Pertaining to thermoclines it is well documented that there is much , Much less oxygen below the thermocline....It is also colder ...Perhaps I should have said colder sub thermocline water holds less oxygen. My Bad....
Thermoclines are normally a large factor in oceans but they can also be observed in lakes. In colder climates, this leads to a phenomenon called stratification. During the summer, warm water, which is less dense, will sit on top of colder, denser deeper water, with a thermocline separating them. Because the warm water is exposed to the sun during the day, a stable system exists, and very little mixing of warm water and cold water occurs, particularly in calm weather. One result of this stability is that as the summer wears on, there is less and less oxygen below the thermocline, as the water below the thermocline never circulates to the surface, and organisms in the water deplete the available oxygen. Bear in mind that even if the water on the surface is 24C ..as shallow as 200 m down it would probably be sitting at around 10C.... with vastly reduced amounts of oxygen. Given that it would be a breeze for sounding Blue to get down there...I still maintain this lack of oxygen will do that distressed , hooked , fish no good at all.------------- Si Vis Pacem para Bellum |
Posted By: herby
Date Posted: 14 Feb 2012 at 12:00pm
|
Im not disagreeing with you at all.
However, all things equal (except temperature) cold water has higher O2 carrying capacity than warm water.
|
Posted By: Moocha
Date Posted: 14 Feb 2012 at 12:11pm
|
Man this fishing is a complicated business huh.... and a science to now it seems
|
Posted By: Jaapie
Date Posted: 14 Feb 2012 at 12:15pm
|
We haven't even scratched the surface yet Mooch.......
------------- "Only when the last tree has died, the last river has been poisoned and the last fish has been caught,will we realize that we cannot eat money" - 19th Century Indian Creed |
Posted By: SumDumBum
Date Posted: 14 Feb 2012 at 12:16pm
|
Herby O2 ...In the science lab yes... In the Ocean below the thermocline...No....
It is for this reason that nothing rusts on the ocean floor , below the thermocline...ala Titanic etc....There is insufficient O2 for oxidisation to take place.
Anyway it is just a factor that I reckon has an impact . Like I said previously ..Only sounding fish seem to die...I have not heard of one expiring on or near the surface. I could be wrong on this point as well. Which would send me back to square one.
I thought about this quite a lot over the years , including my days a a charter fisherman Overseas.It was the collective opinion of most of the marlin anglers in that neck of the woods and at the club we all belonged to. Many of whom had caught many more marlin than I will ever catch. Real old salts they were.
The only way would determine this would be to test blood samples of fish that died deeper and are succesfully recovered and then against fish that are captured on the surface and compare Blood O2 levels... without that set of laboratory results... it is all conjecture and opinion.
------------- Si Vis Pacem para Bellum |
Posted By: waynorth
Date Posted: 14 Feb 2012 at 1:23pm
|
You're both right, but I think you could be on to something with your thermocline hypothesis SDB. Water molecules in cold water are less active, and so fit more closely together, making the water denser. It may still contain the same percentage of oxygen, but the actual amount (molecule count) per unit size is greater, so cold water really does contain more oxygen than a warmer sample taken from the same body of water. As SDB points out, there is little mingling of water above and below a thermocline, and the organisms that create oxygen mostly do so by photosynthesis, which requires light, which is only available in the shallower waters. When they die they sink, and their decomposition reclaims oxygen from the water. Below the thermocline, there is little or no replenishment of oxygen, so the oxygen levels remain much lower than above the thermocline. Even the dead organisms can't decompose properly, which is why we have oil. Years ago diving out at Maui during summer we had surface water temperatures that were in the high-teens/low 20's but on the bottom at 110m it was a consistent 5-6 degrees. This big difference is less pronounced in the tropics, or possibly just occurs deeper, but for an animal like a blue marlin operating at the extreme of it's geographic range it must be a surprising and unwelcome shock to encounter water of this temperature. Interesting thread. Why do blues go deep more than other marlin ? Why don't they come back up if they encounter cold water ? Do they really head north more often than any other direction ? ------------- treat fish like fish |
Posted By: mozz
Date Posted: 14 Feb 2012 at 1:46pm
Same for me. worst comes to worst I run over one of my lures...... $60 vs the amount of time chasing the stupid fish is a minimal amount although we try not to.
|
Posted By: Bushpig
Date Posted: 14 Feb 2012 at 1:54pm
Most of the smokers up north cant have it sorted. I have tried it10 or so times from different people and it's never been good ------------- I would rather laugh with the Sinners, than cry with the Saints |
Posted By: Roddy
Date Posted: 14 Feb 2012 at 3:59pm
|
Bushie,
I'll try and find out how they used to do the big old DOA's in Madeira then. I know it was cold smoked, and took 48 hours or so, but a slab of 1000lb blue there was always a hit, sliced thinly with some lemon and pepper it made a very acceptable smoked fish sandwich. I know the bits we used to get were very large in girth, maybe something to do with that ? As to why blue marlin die ? There are a myriad of ways that can happen, including tail-wraps, exhaustion coupled with lactic acid, heart failure (and this has been documented apparently by dissection), and by what I term hypothermia - the latter ascertaining to those fish that eat, then sound vertically, often with several hundreds of line off the spool, and never stop till they die. I'm with those who say the water temperature down there is a major source of discomfort for these fish, and if the beast's arrival in this body of water coincides with the end of a burst of energy when it may be less able to regain some altitude and get back to the warm water, then I think we have a prime cause of death for some fish. Make no mistake, though, there is much more to this than meets the eye, and as has been pointed out, although exhaustion in a fish is basically similiar to a mammal's exhaustion, their respective methods of recovery are physiologically not, because the fish has to MOVE to recover, whereas the mammal does not. Therein lies the rub, since we have to help the fish to move, and restraining it with rod&reel is going to affect it greatly, no matter where you are in the world. There are countless blues DOA'd every year, from Europe to South America, from Australasia to Mexico. Any time you stop a blue from free-swimming you're treading a fine edge, where this particular specie's physiological make-up is unable to take punishment in certain conditions - in the same way a 100m runner is not conditioned to run a half-marathon, so the hi-speed chase artist that is a blue marlin cannot compete with a reef-skulking black for the endurance game. I can speak with some experience on some aspects of this game, most notably the difference in the number of fish DOA'd through the course of my career, and whereas in the early years we would have half a dozen to a dozen DOA's every year, I would now expect none, in a good year. All this in precise correlation to the way I have progressed as a blue marlin boat driver, changing from a bloke who would resolutely gun the boat and then spend hours backing down to a guy who now tries to put the leader in the hands of the wireman within 20 minutes, max. This does entail a great amount of awareness, black smoke, forward speed, and a multitude of muttered oaths and trodden-on sandwiches. I've said it in this forum for years and many times, and Mozz and Poodle-Boy both agree, YOU MUST get on a blue fast, with the pointy end of the boat doing most of the work, and when the fight has progressed and the runs and jumps stopped, go through the drag changes to bring the fish to the boat, to specifically shorten the fight time and not let it swim for ever at the end of a leash when a crew is either afraid of pulling a hook or taking a leader to hand too early. And conversely, here lies another truth - if you truly want to release your fish, resist the urges of your mates to boat a bronzed and seemingly dead fish, even one you have resurrected from the deep, tail wrapped. Tow the animal, by a bill-rope or a snooter, for a long time, maybe as much as 40 mins. It may seem a long time but many "forgone" blues revive after being brown and stiff for many minutes, and as remarkable as their ease of expiry may be, their powers of recovery are almost as spectacular but much more worthwhile. ------------- http://www.legendlures.com - www.legendlures.com
|
Posted By: stef da maori
Date Posted: 14 Feb 2012 at 5:39pm
Bushie, smoked one couple weeks ago and was unintentionally cold smoked. ( old man was meant to be watching while i was at work) The fish had good colour , but still raw. So i cranked the fire up and cooked for 6 hrs and shut down and left over night. Was perfect.------------- Tama tu, tama ora. Tama moe, tama mate.Maranga mai, me hiika tatou i nga wa katoa. |
Posted By: Tagit
Date Posted: 14 Feb 2012 at 5:53pm
Just tried the first piece of Boulders fish (thanks Mr B). Was a bit light in salt and sugar for my personal tastes, but unlike most other smoked Blues I have tried the texture was very good and not significantly different to a Stripy. Can see a few smoked fish meals in my immediate future 
|
Posted By: Bushpig
Date Posted: 14 Feb 2012 at 9:22pm
I would need to sample to be convinced  ------------- I would rather laugh with the Sinners, than cry with the Saints |
Posted By: Tagit
Date Posted: 14 Feb 2012 at 9:42pm
Smoked Blue on toast for dinner. Can't say that it was too horrible 
|
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 11:21pm
| mate you can cook even a koheru in **** loads of butter it will tatse good ..even the oldman hayes who forgets what a bluemarlin looks like let alone even tastes like would agree.....but comon nz lets get up with the release program ....yeah shure if its your first blue marlin,,keep it... eat it.... do what you like with it..but arfter the first let these jokers go so i got something to chase when i get back to karikari peneinsular, when im a old man!!! |
Posted By: Boulder
Date Posted: 14 Feb 2012 at 11:31pm
|
Weird post bleating on about not killing a fish that was DOA M Dog Would you have preferred that I simply let it become sharkfood? brought home and eaten after it died at the boat seemed a more honourable thing to do at the time
------------- http://www.boulderguiding.co.nz"> http://www.boulderguiding.co.nz">www.boulderguiding.co.nz |
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 11:58pm
| yeah i was just saying if you get a blue at the side of the boat arfter killing your first one !!!!...why kill it...if shes dead on arrival ,,i got no worries in feeding the needy..i wasnt having a go boulder boy..if i was im shure you would no mate!!!!!!but its always going to be a touchy subject boulder fish killing..**** me ive killed enough and i bet im going to kill more as long as im on this planet..we are fishing.. there always is death in this game but i am also trying to let go many as possible without killing them,,if its dead when it gets to your boat for shure bring her home ,,,,nothing wrong with thatin my books |
Posted By: mongreldog
Date Posted: 14 Feb 2012 at 11:59pm
|
Posted By: TOSF
Date Posted: 15 Feb 2012 at 7:45am
|
Yeah I am with you MDog on this one too, I have seen more Marlins strung up for photos so far just this season just on this NZ forum than I have seen in 5 years in central America from 100's if not thousands of boats fishing every day single day, Yeah NZ needs to get up with the rest of the world for sure, a lot of 3rd world countries are far more advanced than us in socially managing sport fish. Yeah sure if it comes to the boat dead then yeah bring it home but killing a Billfish for a photo or and ego thing just plain pisses me off. Always love the comment it taste great smoked, but at the end of the day what doesn't. Nothen wrong with a photo of the fish beside the boat? Are there any release only tournaments in NZ? Portugal is a classic example, all tournaments were kill tournaments, a lot of big Blues getting strung up each year then two or three years ago there National Game fishing club decided all tournaments were going to be release only, it pissed a few people off the first year because they could not string a fish and entries were down up but with in one season everyone realized it was pretty narrow mind killing all these fish, they now are a very proud bunch of fishermen looking after there fish for the future. Amazing how a countries general tournament rules will then flow back to the way people think about the way they fish. I am not a Greeny, very very far from it, love killing ****. But my "personal" opinion is we need to look after our sport fish a lot better. For our Children and also for our industry which so many of us make a living from. My 5 cents worth. Blue Marlin die because we kill them, pretty simple. ------------- http://www.facebook.com/TonyOrtonSportFishingOffshoreAdventures www.offshoreadventures.net http://www.legasea.co.nz" rel="nofollow">
|
Posted By: swordfishsteve
Date Posted: 15 Feb 2012 at 12:41pm
|
Totally Agree with Tony and Marty, far tooo many marlin being killed in NZ for Ego boost and brag photo, think about the future before you stik a gaff in!, Good luck for the Nationals Guys nd girls, ------------- REEL REPAIR GUY - Swordfishsteve, That Is Who I Am and That is What I Do : See More At :www.reelrepairguy.co.nz |
Posted By: mangre 2
Date Posted: 15 Feb 2012 at 1:40pm
|
if you ever come across one it will be burned into ya brain for life anyway ------------- Beautiful is better than ugly, Explicit is better than implicit, Simple is better than complex, Complex is better than complicated. http://oceanmobilemap.blogspot.co.nz/ |
Posted By: Jet_ski_fisher
Date Posted: 15 Feb 2012 at 4:44pm
|
TOSF how.. do overseas fisherman release so many blues alive? ------------- http://www.legasea.co.nz" rel="nofollow"> MH... Catch measure release...<*))))< |
Posted By: Jet_ski_fisher
Date Posted: 16 Feb 2012 at 5:00pm
|
Got a reply but there is no post weired? Peter P and MDog have both given some very good advise on this thread, MDog has seen more Blues than most so speaks with good experience. For me smart team work is critical at the hook up all the gear does not need to be clear to start chasing or backing up on a fish, a good team in the pit and Skipper will recognize whats need to be cleared first so you can start attacking sooner to stop loosing line, every second counts, have a good plan before you start fishing. Running smart angles is important when chasing a fish, some people follow the line when sometimes its better to follow the fish and have the angler pump the rod and pull the belly out of the line. Switch and tease is quick and clean, on a lot of cases the side you have teased the fish is 90% cleared when you have hooked up so you can start chasing a lot quicker. I think it is all about being efficient, confident and smart, Peter P had a good phrase "Fear Fight" sums it up perfectly, if you have a scared fish and a scared skipper its all going to turn to ****. For me it is all about the angles we run and were we put the boat, I run a 82ft Sport fisher so the angles we drive are very important as we can not spin on a dime as some of the smaller boats. I have seen Skippers sit down with small objects on a table and and try and work out what angle they would drive when hooked up on doubles and triples, sound stupid but how else can you learn, killing a fish is really not acceptable in my eyes if you are trying to release them. You would not walk into a cage with a tiger without having a plan. I am sure colder water may have something to do with it as well in NZ and rougher conditions also make chasing a fish slower which will not work in favour of the fish, NZ has some world class crews but we fish in some pretty demanding conditions in NZ so things can and will go wrong some times. makes sense warm water fish,colder water could die from the cold and exhaustion. ------------- http://www.legasea.co.nz" rel="nofollow"> MH... Catch measure release...<*))))< |
Posted By: obald
Date Posted: 16 Feb 2012 at 5:05pm
Don't you just love the way that trips off the tongue  ------------- Random musings on all sorts of things http://obaldnz.blogspot.com/" rel="nofollow - http://obaldnz.blogspot.com/
|
Posted By: TOSF
Date Posted: 17 Feb 2012 at 4:39am
|
Hard Core Gamer, thanks for fixing this for me, I tried typing this late last night after fishing went to edit it and deleted it by mistake, gave up in disgust and went to bed. I put that one down to a IU error (idiot user). Cheers for re-posting/fixing it for me. Obald, it is really 82ft of nightmare and like making an elephant walk a tight rope. Just trying to make a point and hope I did not sound like a snob in the post. T ------------- http://www.facebook.com/TonyOrtonSportFishingOffshoreAdventures www.offshoreadventures.net http://www.legasea.co.nz" rel="nofollow">
|
Posted By: Tone E
Date Posted: 17 Feb 2012 at 8:11am
|
Posted By: TOSF
Date Posted: 17 Feb 2012 at 8:42am
|
I am just the poor old driver Guys, I dream about the day I can own my own 28ft boat.
Just leave me a Blue to catch in it when I finally come home. ------------- http://www.facebook.com/TonyOrtonSportFishingOffshoreAdventures www.offshoreadventures.net http://www.legasea.co.nz" rel="nofollow">
|
Posted By: Bugzy
Date Posted: 17 Feb 2012 at 9:05am
|
I agree with the T & R. Alot of tournaments in NZ are about Hanging the fish up. There is a comp coming up that I am doing and there are 3 spot prizes a day for T & R fish and the rest of the prizes are for hanging fish up with limiting the number of smaller fish classes to one per angler per day but no limits on big game fish per angler per day. Just done whangaroa one base and it was a T & R tournament even though there was quite a few fish up hung up as there is a prize for heaviest stripey. Shouldn't we be pushing just T & R tournaments only and a spot prize for fish hung up?
------------- Never argue with stupid people, they will drag you down to their level and then beat you with experience. |
Posted By: Jet_ski_fisher
Date Posted: 17 Feb 2012 at 9:21am
|
82ft hmmm sex that floats...now that is one impressive lady to drive :) No worry's glad to help :) ------------- http://www.legasea.co.nz" rel="nofollow"> MH... Catch measure release...<*))))< |
Posted By: TOSF
Date Posted: 17 Feb 2012 at 9:41am
|
How about this for a format for tournaments. Tag and release as well as kill but with a few rules to stop to many being hung up. 120 Points for any marlin being released. Minimum size 120kg for a Kill, 1 point per KG, any fish killed under 120kg looses points x 10 per KG. Bigger prizes for more points. Biggest fish is still a side prize. This is most likely being done back home already,still allows a few fish being strung up for the punters and photos but would save a few for the future. Question, who is the better fisherman? The team who catches only "one" fish for the year but it is big? or the team that can go out day after day and catch "more" fish consistently. Some smart arse will say both we all know that, but it makes you think where the major prizes should go. ------------- http://www.facebook.com/TonyOrtonSportFishingOffshoreAdventures www.offshoreadventures.net http://www.legasea.co.nz" rel="nofollow">
|