Deflating swim bladders

[agnes_jack]

Anybody come up with a better way of deflating the swim bladder of fish brought up from deep water?
Around this way we often catch very big cod and other unwanted species offshore and sometimes it can be very difficult to get them to swim down. The method I usually use is to draw a line below the fourth or fith dorsal spine and line up with top of pectoral fin then pierce the bladder carefully. This can still be quite a chore to extract enough air to allow the fish to swim down. You never really know for sure wether the fish survives this crude surgery or wether it has problems later with infections etc. I remember reading sometime ago about somebody in WA coming up with a device for releasing the dhufish over there. I think it was some type of heavy weight that you hook into the fishes jaw that carries the fish back to the bottom and is somehow then released allowing the fish to swim away unharmed. Does anybody have any details on making this device or where you can get them from or just how the release mechanism actually works. I always feel bad about these big cod and would sleep a lot better at night if I was sure that they they would survive the release process. Any advise or info would be greatly appreciated
Cheers tony

[Nugget]

While not big by your cod standards, Mono and I have caught and weighed in big live snapper.
We used a similar method to deflate their swim bladders only we had the advantage of seeing them several days later swimming in a tank.
One trick we learnt from Reef Science was to leave the needle in the fish - don't just deflate and remove it.
Mossy from Reef Science would insert the hollow needle, then put the fish in what he called a "hospital tank" and let it swim around - overnight on some occasions.
You could still see bubbles coming out of the needle several hours later.
As a scuba diver, I can see the wisdom of getting a fish back to depth.
In the old days they used to call a hyperbaric chamber a decompression chamber - in fact it is a RE-compression chamber.
The chamber recompresses the diver to depth then they slowly decompress.
Getting a fish back down would act like a recompression chamber - not sure if it would induce nitrogen bubbles in the fish though - do fish get the bends?
There needs to be some research done on this.
I'm sure most of us would agree with your big fish sentiments.

Dave ><>

[Smithy]

This is a device they have been using in WA. We have also tried using our downrigger and tieing some light mono through the lips but we were unsuccessful. We were in 190' but I expect you aren't fishing that deep off 1770.

A guy who may be interested in you experiences is Mark Mark McLennan, details below. Mark is actually a member of the North Brisbane Sportfishing Club Inc as well as a scientist.

Below is an excert of an e-mail to our club tagging officer Russ Bowman.

"Russell,

Attached are a couple of photos of barotrauma relief devices. The first is simply a 16 gauge needle on a 3ml syringe and the second is the "shot release" or "bomb" made up by the ANSA guys in WA. We are collaborating with Bill (Infofish/Suntag) and ANSA anglers with the aim of tagging 1800 of our target species (total) in the next 3 years. Bill is doing a lot of the groundwork as you would expect. We should have sorted out a standard presentation by the end of next month which we will be showing at club meetings. We also intend to put a kit together for participating anglers with data sheets, equipment and a background on the project.



<<venting.jpg>> <<Shot releasesml.jpg>>

Give me a ring if you have any questions.

cheers,

Mark Mc.


Mark McLennan
Technical Officer, Fisheries and Aquaculture
Agency for Food and Fibre Sciences
Department of Primary Industries

Phone 07 3817 9596 Facsimile 07 3817 9555
Email mark.mclennan@dpi.qld.gov.au
Website www.dpi.qld.gov.au Call Centre 13 25 23"

Hope this advice helps.

Let me know if you have a Sailfish bite up there over Christmas like what happened last year. Do you ever see Billfish there? Peter Stevens has given me a couple of clues but we just end up chasing Spaniards when we are up your way.

[Smithy]

Using the needle. You are right. We go for inline with about the fourth dorsal spike or where it goes from the hard spikes to filaments - that is on Australian Bass - and where the pec fin folds back.

[damons33]

rob, i don't fish past what i way to eat in deep water.
if i catch enuff then want to play around i hit shallows to do it in 30 or less and as we both know if you want serious fun you want tuna spinning which don't have that problem!
look if i get sumthin under size i pierce its gut bag hanging out its gob and you hear it deflate immediate. i know people reckon this don't work but i see them get down and if they die well it probably will feed something anyway so the real key is to only fish for purpose in the megadepths and enjoy your sport in a more eco-friendly depth but hey its only my op!" this indemnifies me to any critisms from any *&^%bags you lolly pops!

[Daintreeboy]

LOL nice ending to that sentence... cracked me up

[banshee]

Another good place for smaller fish is in the "clacka",put the needle in above the membrane and slide it in till it hits the swim blader.

Smithy,I thought perch/bass only frequented the upper layers of dams due to the lack of O2 down deeper,what depths are you geting them at?

[Smithy]

Regularly 50-60 foot but down to 80 foot.

[agnes_jack]

Smithy
Thanks for the info and pics, much appreciated. I will knock up one of the bombs and give it a go. It makes a lot of sense to try and get the fish down without surgery if posible. I dare say that the bomb would have to be rather large around here, because many of the cod we catch are 50lb or more so they hold a lot of air.
Around the early part of this year, Iknow of several sails and some Small black marlin hooked off the rocks on the catwalk, none of them landed though. A few blacks were landed in boats though, I think Pete Stevens got one in close to the rocks. A couple of good sails were also landed in boats. One I heard of was caught out at the nine mile by a fella with a pillie floating out the back of the boat, it was about 5 or 6 foot long. It is something that doesnt seem to have been targeted too regulary out here as yet. Pete stevens probably knows more about them than anyone else around here though. I will keep you posted on any info I hear. I will post a photo on the saltwater pics so you get an idea of the size of the fish we are trying to get down again.
Thanks for your help
Tony

[agnes_jack]

Damons33
I assume what you are saying is that I am only fishing for fun in the deep water. You would be hard pressed to find fish in less than 30ft of water in this area, as most of the spots we fish for trout, red emperor, red throats etc are on offshore reefs in a minimum depth of around 70 to 100 ft so we need to release unwanted fish in those depths also. When we fish for fun we do chase pelagics in shallow water around the headland. But fishing for a feed is when we run into these problems. I am definatly not happy to stab the bladder and throw them back, not giving a damn about wether or not they end up as shark s#@t. Many of the fish I am trying to release safely are old ,quality fish that are an essential part of the ecosystem and deserve the best chance of survival possible.

Agnes jack

[agnes_jack]

Nugget
Do you mean that the fish should be released with the syringe still in place, or are you talking in controlled conditions only? I reckon that this is a very important subject and further research would be great. Nothing worse than killing a fish that you have caught accidently. Interesting that it takes a few hours before the bubbles stop coming out, shows that it is hard to expel all the air when releasing fish on site. Thanks for your comments.

Cheers mate Tony

[Nugget]

Probably not practical in your situation but I was thinking of keeping them in my big live tank for a few hours with the syringe in - then remove it when I let them go.

Dave ><>

[Smithy]

Jack,

actually met with Mark Mc yesterday. This is a very topical thread at the moment with his project going on and the released fish TV adds on at the moment. Get in touch with him. If you do get into the tagging side he will give you a shot release. They have been modified from the WA ones and Ross Cobb is doing them on pounder snapper leads. We picked up a pounder and a three quarter. He suggested using a snap swivel to join them together for the bigger fish. In WA they were releasing Dhufish successfully up to the size fish you are catching. They look pretty close to a Pearly. Bigger risk with big fish is handling them. Picking them up by the jaw will probably kill them. Must separate the vertebrae. Doesn't kill them straight away but in a couple days time. Really need to cradle them to handle them properly. Alf Hogan lost big numbers of broodstock barra at Tinaroo without realising by picking them up by the jaw as you do. Couple days later all his big girls were dead in their tanks. If you can also bring them up slowly that last little bit when you see colour. That is about 10m. That last 10m is where the barotrauma effect doubles.

Below is our biggest Cod to date. It was one of those what do you do with it type situations. Bigger then the 1.2m legal length, too big to cradle (Cod are as greasy as hell anyway) and we probably wrecked its vertebrae taking photos. Do we stop fishing? We were catching good eating Rosy Jobs up to 8kg with these fellows and the smaller Cod eat allright. We tried tieing it with light mono to the downrigger bomb and trying to get it down but it didn't work.

Can appreciate your problems.

http://www.ausfish.com.au/chat/uploads/lukecod.jpg

Other thing about cod is they are a sign of a good healthy reef or so one of the Noosa charter boat operators said on one episode of Rex. He also had the theory on Grinner and Spotty numbers being linked. Might be something in his cod theory as that reef where we got the Roseys and another reef we took cod off never produced as good again.

As for the Billies main hint from Peter was where bait congregates. He reckoned Banana Gutter, 8-9 mile and his bait spot out off Outer Rock were the go. I expect the 2mile would be good at certain times with the amount of bait it holds. Billfish and bait definately go hand and hand in my experience.

[SNELLY]

With trout that I have caught here in Cairns that I have released I used my tag applicator to deflate the swim bladder just behind the pectoral fin. I have tagged over 100 trout using this method and several that have been deflated in this manner have been recaptured. #

Do I think they all survive - well no - but I do know that they have a far better chance if they swim off rather than floating away. #