Light trap design for collecting squid/octopus juveniles

Steve O'Shea

TONMO Supporter
Staff member
Nov 19, 2002
Attached is a file that details the design of light traps I've just made up; the depth of the cylinder is 2 metres, 1 metre for the column and 1 metre for the funnel (for some reason these measurements did not come out on the file [cut/paste from word document into jpg format]).

The netting material is 335 micron (0.335mm), with 1 stitched seam lengthwise in the cylinder, 2 x strengthening canvas seams; the mesh has holes cut into it into which the softdrink bottletops are placed (basically welded with a glue gun); the funnel is a separate piece of material stitched to the cylinder, again with a single longitudinal seam.

The netting is afixed to the marine ply disc by ~ 75 cable ties, each tied through an eyelet spaced every 20-or-so mm around the netting, with 2 small holes drilled into the plywood for the cable tie to go in, through the eye and out again, tied off at the top. I should have a few more pics to explain this as words are rather clumsy.

Am open to any comment/improvement; fluorescent lighting in the bag would certainly be an improvement ... and I'm working on waterproof housings for cheap fluoro tubes.

To keep these things floating subsurface (only just) you have series of ropes and buoys, the entire system anchored to teh seafloor with heavy weights (so as they don't drift away into never-never land in the current. Also, when deploying these things offshore, at night, ensure that you have some sort of strobe or light stick so that you can relocate them.

Must get back to things here .....


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Ahhh...the swish ,swish of the waves gently lapping (as of a raven nicely tapping) lapping at the the boat's laquered hull...
sounds great Herr Doktor...just out of curiosity, have you ever tried the illum-sticks? In the military, we had fairly bright ones that burned for quite a while (6-8 hours) and they are cheap, cheap ! As well as submersible...just a thought...
Love the pics...can't wait to see the results!
I just got one question, are the larval architeuthis phototropic or are they attracted by their food sources which are in turn attracted to the light?
Hi Steve,

Are those the same type of trap you brought down south that time?

I know George brought one over that he had borrowed from somebody at AIMS. It was a similar design but used a fluoro tube in the centre.......lit up the whole bay!

How've they been working?


Thurge, the fishing light idea is perfect; I'll be looking into this this coming week (as a considerably cheaper alternative to what I had in mind); thanks buckets.

Hi Jean; different traps these; just been plodding away on them for the past month or so (design-wise), improvising wherever I can. The light idea (above) is tops; building the lighting system that we used in Otago would be prohibitely expensive (and they leaked; at the end of it all I think there was one operable system).

Hope to have something posted on the traps this week (an update).
Coz I'm insanely busy at this point in time..... :sad:

Here are some pics of the thing in action


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