Threadfin

[Barry Ehsman]

Yea mate, go for it even start up a seperate thread.

[Ronje1]

image S00082.jpg ,looking at top far left think it appears to say 15 mtrs ?? are they fish along there or just part of the bottom structure that appear as smallish humps??.

That's 15m horizontally from the c/line of boat. Yes they are king very close to the bottom so not much in the way of shadows being revealed. Heaps of them.

Those that are higher off the bottom (enough to throw a shadow to the left) are having that shadow hidden by the shadow of the rocky outcrop immediately on the left.

King don't usually "mob up" on top of plain rock bottoms. They tend to school-up in the rubbly/sandy/gaps between the rocky outcrops.

Something else I've noticed is that "how" they school-up indicates something (to me anyway).

If they're all lined up facing the same way, then they don't seem interested in feeding. I suspect that they're lying there out of the main run.

If they are facing in different directions like a handful of fiddlesticks (remember that old game?) that have been released, then they seem more inclined to take a soft vibe or big live prawn.

Haven't done enough work on that theory yet so its only simple conjecture at this stage.

[Ronje1]

I'll re-jig a bit of stuff that I've got about sounder fundamentals and put it up separately as Barry Eshman suggested then.

Take a couple of days.

[Sheik]

Thanks, I for one would appreciate that.

[Ronje1]

See separate thread on sounder fundamentals

[Ronje1]

One of the problems with catch-and-release in respect of threadfin is that they are particularly susceptible to the effects of baratrauma. More than most other fish.

Its not simply a result of depth though.

Its a result of a particularly active gas gland feeding into the gas bladder. Over-invigorated by lactic acid we're told by the scientists.

I use a release weight and/or a venting needle otherwise the king simply won't submerge and eventually die. Nobody wants that (particularly when you've just inserted one of your tags).

I've caught smaller king (80cm or so) in 1 metre of water and basically skulldragged them into the boat so no struggle or chance for lactic acid to build up.

Yet when tagged and released, still went belly-up beside the boat in 1 metre of water.

Release weight worked ok by moving boat out to 3-4 metres of water.

Buggered if I know why.

[Ronje1]

Attachment 121304

Here's another one. 152 cm.

These don't change to females until 120cm.