Killing the nerve endings in a Giants spine

[maz888]

Anyone have any advice on this? Pictures or videos of how this is done? I read a few places that you "simply" push heavy mono or wire into the spine all the way to the tail. I have tried this and it isn't so simple. I tried on smaller fish though (100-180lb range), would this have made the opening in the spinal column to small to fit the mono into?

Any advice on the topic would be appreciated, I curious what I'm doing/did wrong.

Thanks
JM

[simonsez1]

Lot of info here

[Heli Sports]

Anyone have any advice on this? Pictures or videos of how this is done? I read a few places that you "simply" push heavy mono or wire into the spine all the way to the tail. I have tried this and it isn't so simple. I tried on smaller fish though (100-180lb range), would this have made the opening in the spinal column to small to fit the mono into?

Any advice on the topic would be appreciated, I curious what I'm doing/did wrong.

Thanks
JM

Spinal tapping a tuna (without completely removing its head and tail) is very difficult. And quite frankly it's not worth your trouble when there are several other measures that are much more critical to producing the best meat color and quality.

Bigeye and particularly Yellowfin tuna are much more succeptable to burned meat syndrome (Yake) than Giant Bluefin Tuna. The tuna handling document that simonsez1 provided a link to is an excellent source of tuna handling information, however it was specifically written for application in warm-water or tropical RSW (refrigerated sea water) longline fisheries for Bigeye/Yellowfin. The techniques described in that document are very high-tech, particularly the bleeding methods utilizing a high-pressure saltwater washdown with a small guage nozzle, and quite difficult to perfect.

Most Japanese fisheries do not spinal tap Giant Bluefin tuna. I really think that this technique is more applicable to Bigeye and Yellowfin tuna. Very few U.S. longline vessels spike and spinal tap their Bigeye. Those that I have seen use this technique used segments of stiff monofilament mainline and forced it through the hollow spinal chord after the tunas head and tail have been removed. I do not recall seeing any difference in meat color/quality of the boats that did this, compared to the production from the vessels that did not.

I used this same technique to spinal tap large Bigeyes that were landed alive by live-bait boats in the Canary Islands back in the early 1990's, and although I was able to push out high temperature spinal fluid with a strand of stiff monofilament mainline, I can't say it made a significant difference in the tuna's meat color.

The University of Hawaii has done extensive research on spiking the brain and spinal tapping Yellowfin produced in the Hawaiian Ika-Shibi fishery in order the reduce Yake in the tuna produced by that fishery. They found that destroying the brain and spinal tapping helped in that fishery (Yellowfin being highly prone to Yake when captured by handline and particularly during nightime). However, the University of Hawaii concluded that rapidly reducing the core temperature of a tuna was the most effective way to reduce burned meat. The quickest way to chill a tuna is to remove its gills and guts and immerse it in a slurry of seawater and ice.

If I were you I would not worry about spiking and spinal tapping your Giants. It's way more important to thoroughly bleed your fish out! Swimming your tuna before boating them will also help a great deal as well, facilitating their cooling down and allowing them to metabolize built up lactic acid. Removing the head and guts and getting your tuna into a slush tank is going to do far more in producing top quality than trying to figure out an extremely difficult Japanese technique that may not even effect the quality of your tuna!

[LurkerCharters]

I heard the PEI guys swim their fish for an hour before they bleed them and continue to tow them for an hour to bleed them thoroughly. They do this because they want to get the most out of the short season they have up there.

Heli sport, you know your stuff, great info. Thanks

[oceanmaniac]

on both of the local longline boats that i fished on we did not have slush tanks.we never saw any bluefin but this method was used on all yellowfin and albacore. as it was explained to me when you put a tuna on ice with the nerves in the spine still active-ice on the outside trying to chill the fish,nerves in the spine twitching trying to keep the fish warm. this usually results in the meat along the spine becoming "mushy".
so with the fish in the cradle upright-insert the tamaguchi knife or coreing tool,pop out the plug,insert a length of stiff mono down the spinal cavity to kill the nerves...nice,neat and only takes 30 seconds.... that was usually done after dressing the fish

[twofinbluna]

Anyone have any advice on this? Pictures or videos of how this is done? I read a few places that you "simply" push heavy mono or wire into the spine all the way to the tail. I have tried this and it isn't so simple. I tried on smaller fish though (100-180lb range), would this have made the opening in the spinal column to small to fit the mono into?

Any advice on the topic would be appreciated, I curious what I'm doing/did wrong.

Thanks
JM

Never used mono but we rod every fish and it is pretty simple. Just stick it in very carefully and do not force it if it does not want to go. You need to be gentle. Sometimes we hit the backbone when we harpoon them which makes it impossible to go all the way. Again you have to be careful because you can push whatever you are using right out and into the meat, damaging it.

[amarshall]

1 fish on market today sold for 300 yen per kilo. OUCH $1.63

Someone is taking a bath on shipping costs.

[maz888]

Thanks all for the information.

$1.63 that hurts

[Heli Sports]

1 fish on market today sold for 300 yen per kilo.

It's obviously a typographical error!

I don't know where you are getting your information from but the lowest hammer price for North Carolina Bluefin this morning at Tsukiji was 3000 Yen/kilo.

[LurkerCharters]

It's obviously a typographical error!

I don't know where you are getting your information from but the lowest hammer price for North Carolina Bluefin this morning at Tsukiji was 3000 Yen/kilo.

What is the link for the japan market activity? or how are you finding this info?