Canadian Pondweed Control
Viv Rees
My local fishery has apondweed problem and apart from raking it out, which
we have tried, are there any other methods. Understand you can use
weedkiller of some form??
Cheers
viv...@freenet.co.uk
Steve Walker
Rees <viv....@ntlworld.com> writes
>Can anybody out there help me?
>My local fishery has apondweed problem and apart from raking it out, which
>we have tried, are there any other methods. Understand you can use
>weedkiller of some form??
without knowing anything about your fishery, my first instinct would be
'Don't even think about it'. If you were trying to grow sheep, would you
put weedkiller on the field they live in?#
Canadian pond weed is a pain. It grows very quickly, and it gets in the
way when you are trying to fish. On the other hand, it provides a source
of primary productivity in a fishery, providing the vegetable matter
upon which the invertebrates that the fish eat live.
Submerged plants need two things; fertiliser, and light. At the moment,
you have both. Plenty of them, by the sounds of it. If you use a
herbicide, you will kill the pondweed, and its place will be taken by
suspended algae. Your fishery will turn green. If you are lucky, this
will be the end of it. If you are really unlucky, you may find that you
have blooms of toxic blue-green algae.
There is probably little you can do about the fertiliser. My suggestion
would be to try to introduce plants which will deprive the pondweed of
light. Lillies, water hawthorn, etc, anything which grows from the
bottom and puts leaves on the surface.
--
Steve at bourneh dot demon dot co dot uk
John Hill
Steve Walker wrote in message ...
>In article <yqQv5.19319$8r4.1...@news2-win.server.ntlworld.com>, Viv
>Rees <viv....@ntlworld.com> writes
>>Can anybody out there help me?
>>My local fishery has apondweed problem and apart from raking it out, which
>>we have tried, are there any other methods. Understand you can use
>>weedkiller of some form??
>
>without knowing anything about your fishery, my first instinct would be
>'Don't even think about it'. If you were trying to grow sheep, would you
>put weedkiller on the field they live in?#
I agree - be careful.....#
>
>Canadian pond weed is a pain. It grows very quickly, and it gets in the
>way when you are trying to fish. On the other hand, it provides a source
>of primary productivity in a fishery, providing the vegetable matter
>upon which the invertebrates that the fish eat live.
I beleive that this view is slowly being refuted.
I know of several pits (not heavily stocked) that have been treated
to kill excessive weed. The carp have increased their growth rates -
the theory being that thick weed prevents fish getting to the majority
of their food - which lives on the bottom of the lake - not in the weed.
Whatever the reason - removing the weed has dramatically increased
growth rates...
>
>Submerged plants need two things; fertiliser, and light. At the moment,
>you have both. Plenty of them, by the sounds of it. If you use a
>herbicide, you will kill the pondweed, and its place will be taken by
>suspended algae. Your fishery will turn green. If you are lucky, this
>will be the end of it. If you are really unlucky, you may find that you
>have blooms of toxic blue-green algae.
>
>There is probably little you can do about the fertiliser. My suggestion
>would be to try to introduce plants which will deprive the pondweed of
>light. Lillies, water hawthorn, etc, anything which grows from the
>bottom and puts leaves on the surface.
Be very careful - the native yellow lilly will grow in water upto 6' deep,
and will quickly takeover lakes that are shallow all over. Ornamental
lillies are a better bet.
However, my advice would be to get professional assistance, get an
expert in to asses the lake and analyse the water. Its too easy to
totally ruin a fishery for years....
ag...@my-deja.com
"Viv Rees" <viv....@ntlworld.com> wrote:
> Can anybody out there help me?
> My local fishery has apondweed problem and apart from raking it out,
which
> we have tried, are there any other methods. Understand you can use
> weedkiller of some form??
> viv...@freenet.co.uk
>
>my mate had a similar problem with his pool,and he got in touch
with the STWA and they sent some one out and sussed out the
problem and sold him the weedkiller and told him how to use it
it solved his problem. try your local water authority
after all they have to spend the licence money somewhere
barrie lewis
Sent via Deja.com http://www.deja.com/
Before you buy.
Adam Wooldridge
this will work..we done it on our local lake this year.get it from your
local farmer.
super swims,
adam.
Leon Roskilly
The problem is that daphnia and other insect life feast on weed and algae
cells, early in the growing season, preventing excessive weed growth.
Where the stocking level of silver fish becomes too high, they mop up the
insect life before they can do their job.
This can be a particular problem where excess nutrient is getting into the
water (farm run off, nitrates from sewage work discharges etc) either via
feeder streams or water table seepage.
In very bad cases, the excessive weed growth uses up all of the available
oxygen, killing the fish, then the whole lot sinks to the bottom and
eutrophication takes over (the bacteria feeding on the dead matter using up any
available oxygen).
The introduction of pike into threatened waters has managed to get everything
back in balance as nature intended. Pike (about 10% of biomass), silverfish,
daphnia and pondweed, all doing the job which they are supposed to do, living
in balanced harmony :-)
Tight Lines - leon
Steve Walker
<walte...@lineone.net> writes
>
>Steve Walker wrote in message ...
>>In article <yqQv5.19319$8r4.1...@news2-win.server.ntlworld.com>, Viv
>>Rees <viv....@ntlworld.com> writes
>>>Can anybody out there help me?
>>>My local fishery has apondweed problem and apart from raking it out, which
>>>we have tried, are there any other methods. Understand you can use
>>>weedkiller of some form??
>>
>>without knowing anything about your fishery, my first instinct would be
>>'Don't even think about it'. If you were trying to grow sheep, would you
>>put weedkiller on the field they live in?#
>
>I agree - be careful.....#
I've seen a fishery ruined with it.
>>Canadian pond weed is a pain. It grows very quickly, and it gets in the
>>way when you are trying to fish. On the other hand, it provides a source
>>of primary productivity in a fishery, providing the vegetable matter
>>upon which the invertebrates that the fish eat live.
>
>I beleive that this view is slowly being refuted.
I think it depends to a great extent on the species you wish to grow.
>I know of several pits (not heavily stocked) that have been treated
>to kill excessive weed. The carp have increased their growth rates -
>the theory being that thick weed prevents fish getting to the majority
>of their food - which lives on the bottom of the lake - not in the weed.
>Whatever the reason - removing the weed has dramatically increased
>growth rates...
Lots of possibilities; removing the standing crop of plants may have
resulted in further fertilization as they decayed, boosting productivity
by suspended algae and the zooplankton that feed on it, and thus
increasing the standing crop of fish. Certainly, if I were looking to
rapidly fatten carp up, I'd have them in large, clay bottomed ponds with
no vegetation and heavy fertilization... I'm not sure that would be
optimal for all species in a mixed fishery, though.
>>Submerged plants need two things; fertiliser, and light. At the moment,
>>you have both. Plenty of them, by the sounds of it. If you use a
>>herbicide, you will kill the pondweed, and its place will be taken by
>>suspended algae. Your fishery will turn green. If you are lucky, this
>>will be the end of it. If you are really unlucky, you may find that you
>>have blooms of toxic blue-green algae.
>>
>>There is probably little you can do about the fertiliser. My suggestion
>>would be to try to introduce plants which will deprive the pondweed of
>>light. Lillies, water hawthorn, etc, anything which grows from the
>>bottom and puts leaves on the surface.
>
>Be very careful - the native yellow lilly will grow in water upto 6' deep,
>and will quickly takeover lakes that are shallow all over. Ornamental
>lillies are a better bet.
Depends what you are trying to achieve; Personally, I like the sort of
water where you fish into channels in the lily pads. Also, I know some
superb waters which drop off sufficiently quickly that the lillies just
fringe the edge. You are right to advise caution, though, if he doesn't
want that kind of fishery.
>However, my advice would be to get professional assistance, get an
>expert in to asses the lake and analyse the water. Its too easy to
>totally ruin a fishery for years....
Yup. Agreed.
Steve Walker
>>my mate had a similar problem with his pool,and he got in touch
> with the STWA and they sent some one out and sussed out the
>problem and sold him the weedkiller and told him how to use it
> it solved his problem. try your local water authority
> after all they have to spend the licence money somewhere
The EA, you mean... It's a long time since the water authorities were
privatised, and their responsibilities for fisheries passed on to the
NRA, which was engulfed by the EA...
Steve Walker
Wooldridge <adam.wo...@virgin.net> writes
>the solution is to throw in some barley straw.sounds crazy but i promise you
>this will work..we done it on our local lake this year.get it from your
>local farmer.
I've seen barley straw advocated for the control of suspended algae,
particularly Cyanobacteria (aka blue-green algae) but not for
controlling the growth of higher plants.
Steve Walker
<leon...@aol.com> writes
This is true, but most manipulation I have seen has involved increasing
the biomass of macrophytes. The idea is to remove the carp, tench and
bream, and introduce predators. The water clears of algae as predation
upon zooplankton is reduced, leading to more grazing on suspended algae,
and the removal of the large, mud-grubbing species leads to less
suspended silt and less disturbance of plant roots. As the water clears,
the plants come back, and once they have become established the tench,
carp and bream can be reintroduced.
ISTR that there's a bloke at Liverpool Uni who's done a lot of work on
this. I think a PhD student I did some collaboration with was supervised
by him. Brian Moss maybe? Rings a bell.