Tuesday 18 June 2019

Mid 2019 Latest


There was always going to come a time when we reviewed the situation and decide to take our foot off the gas either through success or failure and this year, for the first time in over a decade, we decided we’d not collect spawn from the river and hatch it in the tanks
Obviously, we are delighted that the reason for the change in our usual routine is because of the unimaginable level of success even we never dreamed we’d achieve. The river is now in the best state in terms of roach population density for a generation so the intense level of effort required to collect and hatch the spawn and get the little roach through the early stages of life is more than is now required by us.
So, we have decided on a slight change in our annual routine and to adopt a short-cut policy of taking a few spawning boards full of eggs and placing them to hatch directly into a couple of empty stews (the ones we netted and released the roach from in March, which would have taken the roach we’d grow in the tanks through this coming year)
We have tested the effectiveness of doing this before (the question was always going to be asked) by placing two boards in a tank and two in a stew and we calculated that we got roughly four or five times the survival by doing it the intensive way in the tanks. However, the survival rate in the stew is still a thousand times greater than if left in the river, so still well worth doing. 
The infrastructure is still there so it will enable us to operate far more moderately and less intensively so giving us some of our time and sanity back while still plonking plenty of roach into the river each year. We might even have a look around to see if we can find some of our marbles…
I know we bitch about it every year, but although extremely rewarding and effective in terms of numbers of roach we grow, it is excruciatingly all-consuming work and it was nice to have a break from the intensity.
Now roach are being caught throughout the river in numbers not seen for decades and folks are once again able to watch shoals from bridges just like the good old days. Perhaps more significantly still, I have recently been informed that sampling of this years fry in the river revealed that 5% were roach so showing the positive signs of a natural sustainability we hoped we’d trigger through our efforts. Hard to believe that not so long ago, before we got going, the roach population in the Avon was regarded as being below critical mass and unable to recover unassisted. So, Budgie an me are taking the biggest, fattest slap on the back we could ever have hoped for.
The less demanding roach duties will allow us a little more time to develop our new initiative of looking to improve gravel spawning substrate for the barbel and other gravel spawners in the river in partnership with the EA Fisheries guys.
So far this year we have mapped plenty of potential sites for consideration and we’ll be looking at how each site can be improved (or replicated), which might be through placement of in-river flow deflectors to flush water over the spawning beds to clean and prolong their effectiveness, maybe raking or even gravel-jetting to desilt key areas. It will be ongoing, but the initiative is already out of the starting blocks and has attracted some great support throughout the catchment. If successful, it might even be rolled out on other rivers.
So, back to our roach… The unusually warm April triggered the roach to spawn a few days early this year, for only the third time in all the years we’ve been doing this. Easter weekend was the time and they went to it with the usual awesome display. Even though we have been doing this for many years, the sight of the roach romping all over our artificial spawning boards still blows our little minds.
At one location, we placed spawning boards at the head of a stream to give the vastly increased population of roach that now exists there, thanks to our efforts, additional spawning substrate. We placed four, left two to hatch naturally in the stream, but moved the other two to a nearby weir pool to hatch into the main river; something we might consider doing a little more of in the future.
The spawn placed directly in the stews hatched successfully and the little roach look to be doing fine. They’ll get fed regularly on the fine powdered crumb they’d get if they were here in the tanks after the usual few weeks of brine shrimps.
Those in the other stews and our feeder stream are also doing well and now the water is warming they are feeding and growing nicely.
Once again, we’d like to thank everyone for the fab support and encouragement, and to say now I guess there is no excuse not to get the Avon Roach Project book completed – which is well underway; possibly near half written… You’ve been warned.

Spawning commences and the buzz we get every time we see this is indescribable.

It might look like a violent free-for-all, but it is far from it. The males first establish territory alongside the spawning board then defend it throughout. When the female arrives, he wants to rub his tubercle-covered body along her to induce egg release where he’ll be in prime position to fertilise, which you can see here with the large male nudging the smaller female almost clear of the water.
The significant differences in sizes of roach attending the spawning boards is a healthy indication of multiple year classes existing in the local environment.
Sometimes the action is simply explosive.
Roach love… The larger tubercle-covered male glides up to caress the female.
It sometimes appears as just a melee of writhing roach all trying to get a piece of the action and pass on their genes. This image shows some of the misdirected spawn deposited on the top of the spawning board in the commotion.
Some of the larger males were over two pounds. The one seen here is not far short of that.
Some of this years roach fry at a few weeks old and looking good, having hatched from spawning boards directly into a stew.
There will be plenty of natural food in the stew, but we’ll also supplement this with regular feeds of the special crumb as we do the roach in all the other stews.
Feeding time for some of our two year olds now growing before our very eyes in the warming water.
These are destined to be stocked into the Avon in March next year – but we haven’t told them yet.
An old picture, but our escapee roach are doing very well in our feeder stream. Just goes to prove that if we give them a chance, they’ll take it which is what we have done in the river.
One of the locations for consideration in our gravel spawning substrate improvement initiative. These are, of course, spawning chub, which were seen in early June.

 
 

1 comment:

  1. You Guys leave me full of joy and hope for our rivers. Brilliant!

    ReplyDelete