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Some good fish around.
The Orange River
Up and Down
It looks promising.
Groundhog day

Up and Down
Thu 14th July, 2011

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It's not going to be much of a report this week guys I've had to take some time out to get the truck serviced and the river has been up and down more times than a toilet seat. I managed to get out for a fish on Monday between the squally showers but it was short-lived because the levels kept on rising. Within an hour it was unfishable and I was back in front of the fire. A lot of people don't like fishing in dirty water because they see it as a total waste of time but don't immediately give up and go home. Depending on the severity of a flood it's still possible to catch fish if you change your approach a little bit...the keyword is shelter. As the flows begin to increase debris and any loose stuff is picked up and moved by the rising waters, wash-off from the surrounding countryside also enters the river and it begins to color up. We know fish hate all this because it makes life pretty miserable for them. In order to "breathe" under water they have to extract the dissolved oxygen using their gills. It's a complicated but interesting process and is explained in this slightly shortened article from www.dailykos.com

"Fish gills have three main components. The gill arches, which provide structural support for the other gill parts, the gill filaments, which provide deoxygenated blood flow to the gill surface, and the lamellae. The lamellae are the most important parts of the gills since this is where gas exchange actually takes place. Fish have two main ways of maximizing the amount of oxygen that is diffused through the gill. The first is the enormous surface area of these lamellae, which are cell-thick and sheet-like membranes that are actually extensions of the filaments (the same blood flows through both).The second is the use of a counter-current system of blood flow within the gills. This means that the blood flowing through the filaments and lamellae is in the opposite direction as the water entering the gills. This is accomplished by the fish having a unidirectional blood flow (rather than the bidirectional flow found in mammals). The heart of a fish only has two chambers, one to receive blood and the other to send it out to the rest of the body. Notice that our blood leaves the lungs and enters the heart, a fish's blood leaves the heart and enters the gills. Why is this unidirectional blood flow important? Remember, compared to air, there is relatively little oxygen in the same volume of water. After entering the fish's mouth, the water is pressurized and forced into the gill cavity, and then leaves through the gill slits. Although by closing the operculum (the bony gill cover) the fish can increase the amount of time the water and blood are in contact, the gills must still extract as much oxygen as possible with each gulp. If you think back to high school chemistry you'll remember a process called diffusion. Diffusion is a passive process (as opposed to active transport processes like that caused by pumps) where particles, such as oxygen and carbon dioxide, gradually flow from a high concentration area to a low one, resulting in both areas being equal.In the gill's case the blood (high CO2, low O2) comes into contact with the water (low CO2, high O2) through the microscopically thin membrane of the lamellae. Carbon dioxide seeps into the water and oxygen seeps into the blood vessels. Having a unidirectional and counter-current blood flow the gill is able to exchange more gases because equilibrium between the two fluids is not reached (which would stop the gas transfer periodically). This essentially doubles the amount of gases the gills are able to exchange. Think of the lung as a balloon, air goes in and out the same opening and the gill like a system of pipes, blood flows in one end and out the other."

So back on the Tongariro in order to "breathe" the fish constantly have to pump water through the gill chambers. You can imagine the discomfort they feel if that water is full of fine silt and sand. During bigger floods it isn't only the small stuff they have to deal with. Picture their environment when gravel, stones, rocks and everything else is being swept downstream even in a small flood.
It would be a bit like that "Lost in Space" movie when they are flying through the meteor shower.
I know where I'd head for and it definitely wouldn't be anywhere near the middle of the river. Look at places offering shelter from the main flow like; side channels, these might even be dry in normal conditions, "knotches" in the bank that may cause the water to swirl forming a back-eddy, submerged foliage or even flat shallows that would probably be avoided when the river is clear. Remember you won't see the fish in this water...but they can't see you either. The old saying "fish your feet first" has never been more relevant than when fishing in spate conditions.
The one take I had on Monday happened as I stood on the bank in the middle of a phone conversation with my wife.
The water in front of me was only about fifteen inches deep, while we talked I continued to flick the line in and out of the river. As I raised the rod to "recast" the line suddenly straightened and I found myself playing a very surprised brown trout which was probably around five or six pounds. But my limp-wristed attempt at a strike didn't set the hook properly and after a few violent splashes on top it quickly went on its way. The couple of fresh run fish pictured on the left were caught much earlier this winter in Judges Pool, again out of the main flow in dirty water conditions. They were both hooked within minutes of each other from the same spot near a large submerged rock and took the middle fly under the big indicator dry. What's intriguing about this, is that they are obviously fish making their annual migration.
In normal conditions we would rightly target these using the tried and tested heavy bomb tactics to get down to them deep and fast. Yet both fish were nowhere near the bottom in this slack colored water.
Ross may have touched on the answer a little while ago in one of his daily reports. He mentioned in a discussion about the amount of silt in the river, that as the flow slows any sediment being carried drops to the bottom more quickly. I'm becoming more convinced that fish sheltering in deeper spots out of the main flow during spate conditions, are likely to be found higher up in the water, well away from the concentrations of sinking silt. This same thing has happened to me a number of times and I think its worth experimenting a little bit with this in mind. When fishing during periods of constantly fluctuating levels be extra careful wading and always make sure you have a way out. The Tongariro has the capability to come up pretty fast, look at the angle of a couple of the spikes on this week's flow chart! Even a harmless looking place like the Braids could catch out the unwary fly fisherman. Just imagine being stranded on one of the many small islands if you hadn't crossed back over to the safety of the true right bank in time.

Yesterday I was chatting to three Tongariro regulars that I know, who told me they had left it a bit late leaving Judges. These are big strong Kiwi guys but they had no alternative other than too "hold hands" while re-crossing the river above the Lonely pool...no fish is worth risking it all for.
In the next couple of days it looks as if the unsettled spell of weather will slowly begin to calm down. But there is a heavy rain warning in place for the Tongariro National Park on Thursday morning. With the wind coming from a much colder Southerly direction it wouldn't surprise me to see a lot more of the white stuff on the Desert Road, something to look out for if you intend traveling up. The conditions for the weekend and into next week look spot on, which is great news because I'm busy with Dads seeking sanctuary on the river during the school holidays. With a bit of luck the Tongariro will be kind to us and we'll have a proper report next week...that's the kiss of death.

I knew it!...within a few hours of me posting this report the river has risen to over 270 cumecs... next time I'll shut up.

Keep safe guys

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