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.
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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.
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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. |
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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’… |
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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. |
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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. |
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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. |
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And this is what it’s all about… |
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Crowds of dinky Avon barbel… Very likely just a single year
class, which we are hoping to add to. |
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As we said with our roach ‘doing something is far better
than doing nothing’ so let’s see where this takes us. |
