The latest moves in 'conservation' - update...

[Insect Direct]

Rotonene a fully natural poison :lol:

im fully natural to, but that doesnt mean i cant cause havoc :lol:

[Stella]

Found this today, a really clear and concise document about what, why and how they are going to do it:

http://www.doc.govt.nz/upload/documents ... t-2010.pdf

Very interesting read, I HIGHLY recommend it.

Looks like they are going to electrofish the streams and put the banded kokopu in the trout-free streams and in live cages/boxes. These are set in the stream so water flows through them but the fish can't escape.

Multipass electrofishing will probably remove the majority of the kokopu.

Now people may argue if the kokopu can be removed like that, why not use that to pull the trout out?

Well the kokopu are most likely to be in the streams, while the trout will be in the lake. Can't thoroughly electrofish a lake like you can a small stream! Smaller trout will be in the streams, and conveniently they will probably need less poison to kill than big trout, as it is difficult getting an even mix through a stream.

I fully accept that there will be some by-kill of kokopu, but just like with 1080 and possums, the trout are killing the kokopu anyway. Once the trout are gone, the kokopu will be able to increase, probably dramatically at the start as there will be more food available for juveniles.

[Insect Direct]

Read above doc, thanks Stella. And posts, it does seem like a very well thought out and effective way to get rid of the pests. Almost seems to good to be true 8)

Whats the treatment period thats been proposed? I assume its long enough to kill any potential trout/perch spawn. I dont think i read anything mentioned about how it would effect the spawn.

Anyway as long as its used correctly, it sounds like a good way to go. Zealandia looks like an amazing place, its now on my ever growing list of places to visit

[ryanjury]

Thanks for the link Stella, it does sound like a really good idea It will be interesting to see how it works out if they get consent etc..

[preacher]

I wonder if it would be possible to organise a 'spotlight' nighttime tour after the treatment it over

P.

[Stella]

Preacher, that would be cool! Though it is a single-species monoculture.

I guess in the documents they were talking about the possibility of introducing other rare species. The only locally relevant ones I imagine would be brown mudfish and dwarf galaxias, neither of which would be visible. I guess other kokopu or smelt could work, but they would have to be taken from a landlocked population otherwise they wouldn't be able to breed. Non-diadromous bullies could work in the lake too.

Making the water outlet navigable to juvenile fishies would likely also make it navigable to terrestrial pests. Would be terribly difficult to make that work without it getting clogged up constantly. Bit of a shame.

My father's partner is a volunteer and leads night tours through the sanctuary. Sometimes they get kiwi kicking around their feet!

Friends of mine said they were watching a large banded kokopu there once, lazing about in the sun. A staff member came over and asked what they were looking at. He had no idea about the fish! :roll:

[Stella]

I would just like to post an update on this rather old thread.

The operation happening on the 22nd February and initial surveys suggest that the eradication was successful!! They will continue to survey over the next year and hopefully finally pronounce it a success then!

I wound up volunteering to help with the operation, which was fascinating and I am really thankful that I was allowed to help.

I helped with electrofishing the two tributaries the weekend before the application of rotenone, pulling out around 16 banded kokopu each time and zapping numerous small trout. In all 159 bandeds were placed in a safe area prior to the application, and while there were banded deaths from rotenone, the fish were hiding in really deep undercut banks so it was very difficult to get them out (electrofishing a stream and hearing splashes coming from several feet deep into the bank is very disconcerting!).

On the 22nd February we did the rotenone, it was the only cold wet day a few weeks, typical! It was very interesting watching the 'frontier' of rotenone slowly moving down the stream and I would like to comment that the effect on the trout was quite fast. They went from fine to looking slightly irritated, then rolling and obviously dying, in a very short amount of time.

Again: this site has a number of VERY unusual characteristics that made it possible to do this. There is no way that this technique is going to threaten the trout fishery.

[chopper]

DOC use rotenone to poison the Taylor Dam up behind blenheim regularly in an attempt to remove Tench, Rudd, Goldfish etc. The dam still has heaps of bullies , frogs etc in it they re appear rapidly. They poison the dam every few years because people release fish there regularly in an attempt to create coarse fishing. I go up there often and always see lots of bullies

[purplecatfish]

Just a little bit to add. When debating the pros and cons of any chemical the most useful document to use as a reference is the MSDS or Material Safety Data Sheet.