Here are parts of an article that was written at the time. Nothing with the details you asked about though...
Many years ago someone released some tropical mollies into the hot springs there and they have been breeding prolifically ever since. The mollies have all reverted back to their original colouring but are still pretty.
Every now and then a Hunt is organised, just for the fun of it. This time around it was also a chance for some members of the FNZAS website forum “The Fishroom” to finally meet face to face after only communicating via the forum or chat room. It is always good to put a face to a name but disconcerting when the person looks nothing like you pictured them to look like!
The gathering started at 10am with a short lecture from Dave, the DOC man. He wanted to make sure we were aware of didymo and the effect it has on our waterways. We were informed that as long as all our nets and gear were dried out and left for at least 48 hours, it was then safe to use them in other waters as the organisms would have died by then. Although didymo has not yet been found in the North Island it is probably only a matter of time. Having checked none of our gear had been used in other waterways in the 48 hours prior to the hunt as well, we were cleared to start wading.
The water is extremely hot in places so it was recommended shoes be worn to avoid feet getting burnt. Even so, a few reported mild burns after getting to close to an underwater vent.
A large variety of nets and containers were utilised by all and sundry. Some had very small nets while others had such huge ones we looked to see if they had a ship attached!
Catching the mollies was very simple (usually) as you just swept along with your net to try and catch the fish between the net and the bank, or reeds. Separating them from the mud was another matter. It wasn’t long before the water was very muddy and you couldn’t see a thing, apart from various bodies wading along or coming to an unexpected halt as their shoes got stuck in the muddy bottom.
I ended up with pockets full of car keys, cell phones and sundry other goods as waders realised it might not be a good idea to have these things on them in the middle of the swamp.
The majority of mollies are female, with the few males lording it over the very large female numbers.
This picture shows the steam rising from the water behind Dave and Andrew. This shows how hot it was as the air temperature was reasonable with most wearing T shirts, except for those of us who decided rainwear was a better idea. The fine mist continued the whole time we were there, which was just over an hour.
Although we were told koi carp and catfish used to be found in this area, none were spotted on the day. It is possible the water is now too hot for them and they have escaped through the culverts to cooler waters.
As well as having 20 people from The Fishroom, we had 7 FNZAS clubs represented - Kapi-Mana Aquarium Club, Wellington Aquarium & Watergarden Society, Waikato Aquarium Society, Auckland Fishkeepers Association, Western Bay of Plenty Aquarium & Watergarden Society, NZ Killifish Association and the Marlborough Aquarium Club. So, as you can see, people travelled from as far away as Auckland in the north and Blenheim in the south. A great turn-out and good fun was had by all.