Last evening five of us made a start on removing some of the excess weed and the filament algae from the top end of the Tarn. This proved to be a highly entertaining and amusing experience the highlight being when one over enthusiastic member went for an involuntary swim. However, despite the organised chaos some good progress was made using a weighted net and long-handled rakes.
The net was not as effective as we had hoped because, despite some lead weights along the bottom edge, it had a tendency to ride up over the weed rather than dragging through it. The rakes were very effective though and suggest that the industrial strength rake that Gavin has had made will make short work of clearing pockets and runs through the densest of the weed.
The plan now is to deploy the new rake to clear a passage from the boat house to open water and then to open up a few areas to permit deeper fishing.
I’ll update you on when this is likely to happen, but best current guess is next Tuesday.
It would seem that momentum is building amongst Council to tackle the worst of the Tarn algae tomorrow evening. This will inevitably cause some disturbance at he top end of the water so any member contemplating a quiet fish late on tomorrow is best advised to reschedule. You are of course welcome to lend a hand with the weed rake.
The objective is to clear a few pockets in the weed to assist fishing, get out as much of the filamental algae as is possible whilst retaining much of the beneficial weed to help with aeration of the water especially in this hot weather.
The removed material will be spread on the bank so that inverts and any crayfish trapped in it can escape back into the water.
Looking at the returns at he lodge this morning it’s evident that this hot, dry weather is having a detrimental impact on fishing. A good few members who would usually catch close to the limit suffered blanks last week. Not all though. Two members got their full bag. Whether this was down to skill, weather conditions at the time they fished or just good luck is a matter for debate.
It’s cooler today and we have had a couple of showers which, added to the overnight rain, have freshened things up a bit whilst having no impact at all on the river. It will take many hours of steady rain to raise the river level to fishing conditions and I see no prospect of that happening this week. Now, regular readers will know how accurate my weather predictions are so you can now expect floods of Biblical proportions.
The coots have four chicks. Little bundles of black fluff that bob up and down on the water and follow the adults around in and out of the reed bed. Let’s hope that they fare better than the cygnet.
We did the annual crayfish check this morning under EA licence with nine students from Malham Tarn Field Studies Centre. Of the ten traps that I put in last night eight had creatures in them which is a good result.
I have been somewhat concerned about the native crayfish at the Tarn. About four years ago there seemed to be a significant dip in the population as evidenced by trapping. Most of the creatures caught then were very large with few youngsters and this trend persisted for a couple of years. The problem (if such it was) coincided with a couple of very severe winters when the Tarn was frozen for 3 months.
Last year there was evidence that the population was recovering and this check has confirmed that. Most of the creatures caught were around 25mm to 40mm (all within the breeding profile for native crayfish) with none of the big 50mm plus males that we used to get. So this suggests to me that we have a lot of 3 to 4 year old crayfish with nothing much older than that. The Tarn crayfish do seem to grow quite quickly. It may be that the big creatures have now died of old age. We shall see over the next few years if we begin to see evidence of the traditional age profile with more 50mm plus creatures and high numbers of younger males and females.
I’ll get Paul to do some analysis sometime and see what conclusions he draws.
But for now all this leads me to the conclusion that we have a very healthy water body that is more than adequate for supporting some very healthy trout.
Another scorching day. Apart from a brief cloudy interlude around mid afternoon there has hardly been a cloud in the sky all day. I commiserated with one intrepid member who made a long trip this morning to fish the Tarn. He had accommodation booked so felt obliged to travel up despite the slim chance of decent fishing.
Still, this spell of decent weather does have its up sides. I cannot recall harvesting so many raspberries at this time of year and if the heat continues for a few more days I may well get tomatoes before September which will be novel.
Some while ago I mentioned that the coots that inhabit the Tarn seemed to have gone missing this year. They are back. I spent a good while sat quietly by the water on Monday afternoon and watched a pair of coot swimming in and out of the reed bed. Judging by the behaviour it’s just possible that they have a nest in the reeds.
Yet another glorious day and the river is back to bare bones so fishing will be pretty much a non event until rain returns. The forecast is for this dry spell to continue until mid August so the Tarn will offer the only viable fishing for the next couple of weeks.
We are carrying out the annual crayfish check on Saturday morning so the traps will be in place from Friday evening around the top end and a dozen students will be present between 10 and noon on Saturday helping to process the catch . The Tarn is best avoided until things return to normal quiet mode from 12.30 although there are tentative plans to tackle the worst of the weed after the crayfish monitoring has been completed. I’ll update this info on Friday.
I did the Turn Dub monthly invert check this morning. Results are very good with all families represented by average numbers of individuals. Results always vary month by month so it does help considerably to have records going back seven years. These show no real trend either upwards or downwards although there are slight variances comparing one July with another. These I think are due to prevailing conditions.
There are always more stonefly at this time of year and fewer baetis (olives). The latter having hatched heavily in early summer.
I was struck by the amount of bankside vegetation that’s grown up this year along the margins above and below the Dub. It’s a good few years now since we fenced and planted this area. The trees are beginning to make a real difference and the banks are ablaze with ranunculus which is beginning to colonise the water margins. There are even clumps amongst the big boulders in the river itself. The only negative is the infestation of sheep on the west bank. They are getting under the fence where the bank has been washed out above the Dub and whilst their numbers are not sufficient to severely impact the herbage it would be nice to get them out. I did investigate this last year, but it’s a tricky job and I’ll need to give it further thought.
A wet day has seen the river rise a touch. It’s far from perfect, but there is fresh water now on all the runs and the pools have been replenished so there could be some decent fishing over the next couple of days.
I shall take this opportunity to do an invert check tomorrow. There should be enough water at the two sample sites to make kicking the substrate productive. I really must get around to publishing the results of these (sometimes) monthly checks. It’s all very well the data sitting on my computer, but on my hard drive it’s of no practical use to anyone, but me. What I plan to do is to put the monthly analysis together with trend graphs on the members’ website and place hard copies in the lodge. I know that members who fish the river regularly have their favourite fly dressings, but some may wish to experiment with patterns that more closely reflect the inverts that are likely to be airborne from month to month. These can be identified by a sudden drop in nymphs as they hatch and become subimagines prior to full sexual maturity.
I went to the Tarn yesterday evening and reversed the polarity on the outboard so that it does go forward when asked to do so. I also took it for a trial run to check that it’s working Ok. It is so it’s now ready for use.
This reminded me of a tale told to me by a friend of may late father who served in the navy during WW2 as a Lieutenant Commander engineer. Now as most of you will know communication between a ship’s engine room and the bridge was often limited to speaking tubes and a bridge telegraph. The latter device was mechanical relying on belts and pulleys. Between some senior officers there was occasionally conflict (not always absolutely friendly) and there could be a battle of wills as to who actually had control of the ship. A favourite engine room trick was to reverse the belt on the telegraph so that the device on the bridge showed the ship as moving astern when it was actually steaming ahead or vice-versa. An early and not always fully effective version of fly by wire.
A momentum is building that should see the worst of the excessive weed tackled over the next week or so. A weed rake is being made that should enable us to attack the problem with some precision. The aim is to clear pathways and pockets in the worst areas that will open up additional fishing and reduce the chance of further problems with the outboard.
My musings yesterday about the Tarn weed prompted an amazing exchange of email correspondence amongst members. The consensus it that we should do something to reduce the extent and volume and much fertile imagination has been expended on how the weed might be reduced without adverse impact on the general habitat and ecology of the Tarn.
A momentum seems to be building so I’ll keep you all abreast of developments.
Thanks to Gavin’s usual generosity we now have a replacement electric outboard. I shall need to change the polarity on the motor (it presently drives forward when put in reverse and vice-versa) so please don’t use it until this has been done – probably tomorrow afternoon. The motor is much more powerful and has been used with great success on Scottish hill lochs so it should prove more than capable of dealing with the Tarn. However, please do try not to plough through the weed at the top end until this has been reduced.
The heavy showers that have been a feature of this week are contributing little to the level of the river which remains on the low side. Evidence suggests that the deeper pools can be productive if fished and the Garden pool offered up six fish a few days ago. So although conditions are far from ideal a few hours fishing the pools may not be entirely wasted.