Backyard Aquaponics
A place to discuss aquaponics

i agree what i've always done with large amounts of fish (mainly tilapia) is get a process going, either take batches in ice or benzocaine if not eating them, calm them down then i persoanlly like to give them a crack over the head to be sure and humane.
Even with some relatively heavy and prolonged exposure to either iced water or benzocaine, without a bash i've seen some fish start to flap around even when completely gutted or whiclst having histology samples taken, which is not nice at all..

anyway my view is they should be treated with respect and killed as quickly and efficiently as possible...

Iki Jimi or is that iki jimi is simply, brain spiking a fish. Most fishes brains are located slightly behind and above the fishes eye. Some can be bloody hard to find but you know when you hit it when the fishes fins flare out then the fish relaxes. The blood contained in the fishes flesh retracts to the gut cavity, thus producing a better coloured and flavoured fillet...
IMHO it is very quick and if you're any good, there is minimal blood

... and I found this explanation on the link below
Iki jimi
Getting the exact spot on each different specie can take some practice but it's generally easy to pick - about one eye width back from and slightly above the central line of the eye, roughly in line with where the pre-operculum (false gill cover) would intersect with the lateral line if it was to continue on (the lateral line) through the head of the fish. Some vary but not too much.

ANDO
http://archives.westernangler.com.au/cg ... az=read_co

Slippery fish make this a difficult task for the squeamish I fear.

Remembering that the ppl performing the procedures, are not fish handlers by trade or hobby, but volunteer environmentalists trying to exterminate a pest.

When we used to catch carp in numbers from the murray, we'd have a hatchet sitting on the bank and we just chop their heads off as we land them - quick and easy! I think its only when your processing fish for food that you need to take a more subtle approach.

We used a technique called " Whack'em and Stack'em " worked quiet well

Is it just me or does anybody else think that the term "Humane Killing" is an oxy-moron?

totally

..well I think humans would have to be the most prolific killers on earth! I think "humane" and "kill" go well together - maybe not the same context as its intended though!

So provided we're killing the animal for the good of the earth (being humane to the earth) we could treat them with compassion, and reduce the pain and suffering felt by the fish (being humane to the fish)

Big Fish ( 5 kilo +), Pointy Knife straight through the the top of the head through the brain. quick confident movement
Small fish (Under 5k) index and middle fingers one in each side of the gills, Thumb on the back of the neck quick confident movement pulling the head backwards, snap goes the neck.
Snapping the neck appears quicker death from my experience and only takes a second.

Bludgeoning appears cruel and a slower death

Unfortunately none of these methods are for the squirmish, but after you have broken a few necks it's a lot easier.

cheers
Ron

I'm really interested in a resolution to this problem.
The problem stated clearly as I understand it.

There is an infestation of a vermin variety of fish.
Plans to catch thousands of these fish are being made.
The fish need to be slaughtered by squeamish environmental volunteers
The fish are likely to be SMALL - making many techniques impractical.
The fish are then to be buried along with saplings in a nearby regeneration area (not sure about this but there is a vague memory that this was mentioned)

So the problem remains: how do you dispose this many small fish, reducing discomfort to the fish, and emotional discomfort to the volunteers??

A suggestion that was made to me by a Vet Nurse, was to have a tank, and run the exhaust of one of the vehicles into it, saturating it with Carbon Monoxide. It seems to kill ppl peacefully perhaps it will work well with fish?
I liked the suggestion, because it was portable, simple and available away from a lab.

You mean like giving the sheep a nice safe truck ride to the slaughter house ? or patting a cow before you put the bullet through it's head ?

well yeah, especially if you're gonna eat him. You don't want him to be stressed, or the meat is tough. But it's not about killing the animal, it's about cruelty. There is nothing worse than false hope.

Whilst I realise your comment was tongue in cheek, I do agree with you.
Not so much a safe ride to the slaughterhouse, as a comfortable one.
Of course the smell of those places is enough to stress out an animal.

I am convinced there is a market for mobile slaughterhouses

frank