Sunday 5 June 2022

Avon Roach Project BARBEL News

Some will already have heard that we are shifting/broadening our focus, as the roach project demands a less full-on level of input; although we are still hands-on with habitat stuff, spawn relocation and advising folks on other rivers, and will always be.

The ‘what about other species’ question has always been put to us regarding the core principles of the roach project, and the better we got at what we were doing with roach and the more fishy stuff we understood, the clearer it became.

Now we have taken the plunge.

Just as there were ‘elbows on knees’ contemplative moments at the beginning of (in fact all the way through) the roach project, so there were regarding some other rather obvious issues in the river. One being gravel spawning substrate enhancement which would benefit barbel and others, including salmon and trout if we needed to sell the idea.

The ‘penny-drop’ moment came to us after a monster flood in, I think, 2012 and although, on the face of it, there is nothing good about a flood, the shifting and desilting of the gravel in the river did have one positive consequence, an obvious increase in egg survival and fry recruitment for gravel spawners resulting in a noticeable proliferation of dinky barbel in the river.

All gravel spawning species need loose gravel for egg survival and fry recruitment, but particularly barbel as they spend a slightly longer period after hatching between the stones as larvae, where others ‘swim up’ earlier.

Improving gravel quality in rivers is a recognised practice for salmon and trout so we thought the same would unquestionably also work for barbel, which had probably just naturally occurred.

The compaction and siltation of spawning gravels in our rivers significantly restricts egg survival and therefore fry recruitment, and there are a number of factors responsible such as runoff, poaching by cattle, bank erosion, increasingly exacerbated throughout the country by Himalayan Balsam (don’t get us started… there’s not enough space here)…

Even here on the Hants Avon, locally, every spring, we see huge mounds of topsoil as big as a house sitting on a field by the river, which is then spread and planted with maize. Then in autumn the maize is harvested and the field is left, where almost every winter a large low-lying section of it floods, even in fairly normal winter river levels, taking goodness knows how much of the soil into the river. Then the following spring, we see new mounds of topsoil delivered and the whole thing is repeated. We have tried to address this issue in partnership with the EA by suggesting secondary planting with clover to prevent the run-off but, of course, these things need incentivising, rather than a bunch of fishy-folk asking farmers to stop their dirt washing into our river.

So, with our motto being ‘doing something is better than doing nothing’ (although lately, following our roach success, it’s become ‘don’t you just love it when a plan comes together’), we decided to initiate a scheme where the gravel at specific spawning sites on the river is desilted and cleaned at critically timed points in the year to optimise effectiveness for spawning barbel: so close to, but not too close to spawning times so the gravel is clean and loose, but far enough ahead of spawning to allow the recolonisation by invertebrates, the vital food of the barbel larvae, but not too far for siltation to reoccur. See, I resisted writing larval barbel…

Just as our thoughts on roach started with us getting together with the EA Fisheries guys and tabling our ideas, so the gravel spawning substrate enhancement project did too. And, once again, the EA were in full support. As well as our existing partnership with Fisheries, the EA Geomorphology guys will also be involved.

The plan was to select a few sites to start with, which will be added to, and assess the need for improvement, firstly simply by getting in the river with rakes and gauging the compaction and siltation levels, and manually loosen and clean a few obvious patches.

However, although thoughtfully timed, all areas would have to be thoroughly checked before we commenced our disturbance for any signs of spawning fish, salmon redds and anything else we might negatively impact upon, and avoided or abandoned if discovered.    

In time as the project broadens and the equipment and people become available, we can take ongoing sediment samples which might more accurately determine the level of siltation and required improvement at different sites and the methods we use to achieve it, be that simply raking annually or jetting with powerfully pumped water, or even perhaps installing permanent in-stream habitat features to flush water over the gravels and reducing the need for repeated manual raking or jetting.

However, there is already enough support in the valley for an annual coordinated gravel scratch… There is a bit of a knack to it which can easily be shared and will also have to be critically timed, but we are confident we have enough to make a huge difference even at this basic level of effort.

So, once the partnership and an initial plan of action was agreed, we made contact with folks along the river; clubs, land owners, river keepers etc. and got an amazingly supportive response from almost everyone – possibly off the back of the roach project success… those crazy nut-jobs at it again.

The fact is, there is nothing really not to like. It’s a relatively ‘no-fail’ undertaking with absolutely no negative impact that has every chance of improving the barbel population density.

We chose four widely spaced sites to look at; starting with Sopley Mill Stream, the head of which is a known spawning site where any improvement and resultant increase in fry would play nicely into the fry bay we excavated half way along a few years ago (known as Trev’s damp patch) which is still functioning at an amazing level thanks to the ongoing maintenance by the Christchurch Angling Club river team who look after it. The whole mill stream should be a good barometer of any success over time.

We went along supported by the land owner and stalwart ARP supporter, David, and a bunch of good guys from CAC, who have already offered themselves up as partners in any annual doings. They all offered to get in with rakes and help on the day, but health and safety (EA, not us) meant that only Trev and Phil Rudd of the EA got in and did the raking. Our Budgie also offered but said he’d only go in up to his knees… They raked two sections of the known spawning area, which can clearly be seen in the pictures below, demonstrating just how effective a simple undertaking like this can be. It literally went from being like walking on concrete to walking on, well, loose gravel in a matter of just fifteen minutes.

It was then on to Bisterne and a wonderful couple of hours spent with keeper Paul Coombes. Here we were looking at a vast expanse of open gravely shallows which might lend itself to some large-scale attention in the future, but more about that prospect in a later communication.

On the actual spawning areas, we were quite encouraged to see the gravel in pretty good condition as it was being naturally cleaned by the pinching of the flow alongside little promontories and islets, confirming the potential effectiveness of any permanent instream features we consider installing.

Next day it was way upstream to Britford, just south of Salisbury, and under the guidance of keeper Stuart Wilson, we got in and raked an upstream section of a large spawning area where he sees the barbel each year. We did half as an experiment to determine whether the barbel will actually choose a raked area, as we know fish feel the percolation of water through loose, uncompacted gravel; a bit like when we tested the roach spawning boards by placing them away from the natural substrate so the roach would have to choose them… not that we are expecting anything we do to gravel to come close to what we achieved with our ‘magic’ roach spawning boards… but now, as then, we’ll be looking out for anything that gives us an advantage or refines our effectiveness.

Day three and we were back on the middle river looking at some shallows below one of two weirs with owner, ARP supporter from day one and now good friend, Peter, who was very keen on being a part of our project.

Unfortunately, one of the things listed above as causing siltation was evident and abundant with cattle accessing the river and using the shallows to cross from one side to the other.

Quintessentially English and seen in paintings and pictures down the centuries, it’s only now that the horrors of such rural Englishness continuing in such a different time are beginning to be understood.

We raked the gravels below, but quickly gave up as the level of siltation was way beyond being remedied with rakes. There were also other rather unpleasant brown deposits.

A sensitive matter, as the cattle owner has been there far longer than us and has probably grazed in the same way for years. There might even be a grazing policy on the land, as there are in many other places, set by Natural England.

The only way it can become a viable fish spawning area would be for the cattle to be fenced and stopped from crossing and a substantial fixed instream habitat feature, or two, be installed to pinch the flow and flush water across the shallows. Fortunately, Peter was receptive to the idea. So, watch this space…

It was very interesting to see such a contrast in conditions in just the four locations we looked at this year.

There was actually a fifth site which Trev visited with positive effect above the railway bridge just south of Ringwood and above what’s known locally as Severals. This site was already on our list for future attention but time, conditions and easy access allowed an early visit.

So, what next?

We will initially concentrate on known spawning areas but will, over time, also create additional areas throughout the river, as we know the fish will be attracted to an area if the conditions and, of course, location are favourable, using the same principles as our roach regarding upstream migration to accommodate larval drift, and good oxygenated flow over suitable spawning substrate, which we can easily create. And we know that not all fish return to the place of their birth to spawn at maturity, so creating additional options could add significantly to the effectiveness of our efforts. This might also mitigate the differences in effectiveness of each site… the old ‘more the merrier’ approach we adopted with our roach.

We have a list of additional sites and permissions already for next year and beyond; a kind of hitlist, which range from above Salisbury, courtesy of Salisbury and District Angling Club, right down to the famous Royalty Fishery in Christchurch, courtesy of new managers South West Lakes Trust, perhaps one of the most renowned barbel stretches of river in the country, in its day, with a history unmatched almost anywhere – so what an honour it’ll be to apply our influence here.

We have also established some potential sites over on sister river the Dorset Stour for future attention and are in communication with the relevant folks… so, who knows, Avon today, Stour tomorrow, then the world…

Seriously; there is no reason why elements of what we do here on the Avon can’t be replicated and undertaken by forward-thinking, resolute folks on other rivers, with the right EA and NE consents and guidance, just as elements of our roach project have…

Finally (thank goodness for that, I hear you say), there have, down the years, been a few questions over the compatibility of barbel and roach in the same stretch, with some suggesting that an increase in barbel numbers has directly impacted on the roach, so obviously this is something we’ve had to consider.

We are sure the jury’s still out for some, but are confident that we will not be compromising the wellbeing of our roach and our ARP efforts by improving barbel numbers in the Avon and base our views on the fact that many of the Avon’s roach strongholds, as well as other rivers, past and present, have been shared with barbel; existing in slightly different environments, but still often within touching distance.

Vital pre-raking survey of the site to assess flows, depths, drop-off points and actual compaction to optimise effectiveness of our efforts.

Trev and Phil get stuck in to rake the agreed areas, starting upstream and working down.

They did two fairly large areas and a simple phone photo through polaroid glasses shows the very clear difference between the raked and non-raked area.

In this world of negativity and desperation, it was good to have a laugh; and the humour was about as non-PC as it is possible to get… You had to be there to be offended. Thanks to Dave Taylor for the perfectly timed photo.

And, it was good to get Budgie along, as the whole thing is partly his idea. But it was a bit touch ‘n’ go as the meadows were wet from overnight rain.

But we had the assurance that if we did get the van stuck, owner David would drag us out. And there were a few heart-stopping moments.

With so many spare hands it seemed only right that Trev was the target of the heckling… You had to be him to be offended… Big green jelly-baby with an Allan Shearer hairline he still argues is ‘full-coverage’… 

Up to Britford and we were joined in the river by Jim Allan of the EA and Lewis Swift who took the pictures when he realised just how leaky his waders were.

Only a picture of some stones on a riverbed, I know, but this again clearly shows the contrast between raked and non-raked areas of the spawning site.

The shallows below one of Peter’s weirs and, although a quintessentially rural English scene, with our rivers now a far cry from the days of The Hay Wain, the negative impact of such historical customs is far more extensive.

And this is what it’s all about…

Crowds of dinky Avon barbel… Very likely just a single year class, which we are hoping to add to.

As we said with our roach ‘doing something is far better than doing nothing’ so let’s see where this takes us.