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Q. Will salt
kill NZ mud snails?
A. The California Department of Fish and Game has
tested weak to very strong solutions of Salt water for killing New Zealand
Mudsnails but they survive. The snails have an attached "trap door"
, (an operculum) that they can close which completely seals them in their
shell. This allows them to survive many chemicals. There are a number
of tested chemicals, such as bleach, where that was a problem. Copper
sulfate has long been known to kill many aquatic animals. The bottom hulls
of boats are painted with materials containing copper to keep barnacles
and other organisms off the hull. From the successful testing of copper
sulfate it also appears to force the animal to relax its operculum so
that the copper can attack the animal. Testing of Formula 409 cleaners
with a good degreaser and disinfectant in it has demonstrated that the
degreaser forces the snail to relax it's operculum so that the disinfectant
will do its job. See the cleaning instructions page for the only two Formula
409 products that have the degreasers and disinfectant.
Q. What about
keeping your boots in a 5 gallon bucket of salt water for a day, then
washing them off in fresh water? I would think that salt would have the
same effect on the NZ snails too. It would be a lot easier than 409 or
freezing the boots.
A. With respect to salt water see the above question
and answer. The recommendation for Formula 409 is to soak you equipment
in a Solution of Formula 409 Antibacterial / Disinfectant cleaner
like you are suggesting. But all day is not required. No matter what chemical
solution one employs rinsing is always recommended. Yes, freezing your
equipment generally would be hard to do unless you have a large empty
freezer or are in a climate where it freezes all night. I have nutty friends
that like to fish on those cold wintery days.
Q.
"Got a question-not doubting this info but we have these in the Colorado
drainage and some other rivers. Also, they've been in the Snake system
in Idaho since the late 80's. These areas still have trout, don't they?
If they get into a river system,is it really the end for fishing in that
area? Just curious."
Statement found on web: "I do not think they will cause as big of
harm as feared. Not to say they aren't a problem though. However closing
waters to fishing is not the answer. Anglers just need to clean waders
if they fish waters that have these snails."
A. There certainly
still is a lot of unknowns about these infestations. Some of the recommendations
may seem over board but we just don't know enough yet. It is better to
be safe than sorry as they say. I have heard a rumor that there is a location
where these animals have invaded and there now are not any fish there.
But I can not find any proof supporting that. There is anecdotal evidence
from fly fisherman that there are less fish and smaller fish in areas
where there are heavy infestations of snails but I don't know of any "in
stream" research that can support that. That maybe because there
was not any research showing what the fish populations were before the
infestations. However, there is laboratory testing that shows that fish
in the least loose weight when their diet is primarily mud snails. If
they lose weight due to inadequate diet then like us it may mean that
their immune systems are some what depleted also.
Anglers certainly need to be cleaning their waders after fishing waters
that have New Zealand Mudsnails in them. But it is my opinion and the
Colorado DOWs opinion that our wading equipment really needs to be cleaned
after fishing any body of water as we will not know that a body of water
has a new infestation until long after the snails have a dense population
established. Thus we need to always be cleaning our equipment to prevent
dragging some of these unknown populations to new bodies of water.
Statement
found on the web: "Whirling disease severely damaged the Gunnison
river. I don't think these mud snails will cause anything close to that."
A. That is the opinion of a number of fishing enthusiast
but there is not much evidence supporting that view. But if we do not
assume that something bad is going to happen and work to prevent the spread
of the New Zealand Mudsnails we are sealing our fate to whatever they
do. Once they are in a river system there is no way to remove them. Maybe
in 10 or 20 years a biological method for controlling populations may
exist but historical evidence for other invasive species indicates that
is not likely to happen at all. In New Zealand there are natural biological
controls including a worm that sterilizes the snails. But in numerous
places around the world it has been demonstrated that introducing natural
predators and biological controls to control an invasive species in turn
become as big or bigger environmental problem.
Q.
What
about just hanging your waders out to dry for several days? If you dry
your waders on both sides for a couple days, I really don't see how you
are going to make enough "damp media" to transport the buggers.
A. Thoroughly drying your equipment will work but
it must be a sufficient period of time and every thing must Totally dry.
Felt soles can remain damp for a very long time. In the laboratory snails
have clung to a damp surface for as long as 50 days. The have remained
alive for as much as 8 days without any moisture. Clumps of sand and mud
must be removed, Drying equipment in the sun on Hot days and low humidity
environments is a recommendation, see the cleaning procedures.
Statement
from the web:
I think every watershed is a bit different. Oh, I'll do my part, but I'm
not going to dump a bunch of 409 solution on the ground shoreside, either...
There are other ways to hurt the environment than transporting mud snails-
like couple hundred anglers a day dumping 409 out at the creek's edge.
A. You should not be dumping the cleaning solution
or the rinse water onto the ground or into a storm drain.. It should be
dumped into a building drain to goes through a waste water treatment plant.
There is evidence that different watersheds do have different responses.
Fast flowing rough and tumble very cold waters such as in the high upper
mountains have demonstrated to be some what inhospitable to the snails.
However, less severe gradient water ways with lots of algae and stabilized
temperature ranges such as most tail waters fisheries and some spring
fed streams seem to be excellent habitats for these snails.
Statement:
The DOW pretty much said they don't think there is much they can do to
contain these, in every state they are found they slowly spread, it could
be from a lot of things too. Boats, waders, boots, fish, birds, etc. They
also said the snails prefer warmer water so they may not spread as fast
or as well here.
A. The DOW can not do much except post signs and
educate the public. In
the Colorado DOW management plan they state that they think it is possible
to delay their progress through public education and the public taking
action. If we all clean our waders
we have a change to at least delay their progress. Our actions help set
examples for others. The other states did not have the benefit of knowing
much about the snails when the snails got a foot hold in their states.
Colorado has a slight edge in that their experiences and some research
to help guide the way.
The waters that the snails are going to find the most hospitable are all
the tail waters where the waters have a narrower temperature variation
and a rich algae environment.
The majority of the rivers that are infested in California are the rivers
that are open and heavily fished in the Winter. It could be that the same
water fowl at one river only move to other rivers frequented by fisherman
in the winter time but I doubt it; through out the whole year.
There is still a lot unknown about the snails but there are reasonable
indications that the majority of the populations were transported by fisherman.
What is one to do? Throw their hands in the air and say I am defeated
or fight to keep the quality of our favorite fisheries as long as possible?
We need to battle to maintain the quality of our fisheries.
Q. Can we
still use Clorox mixed with water?
A. A solution of household bleach is NO LONGER recommended.
The CA DFG testing demonstrated that some waders are damaged and solutions
of household bleach are very ineffective at killing snails when it's operculum
is closed. (Trap door kind of thing the snail closes over it's opening)
Testing demonstrates that short exposure to bleach causes the snails to
expel baby snails as they die. The end result in the tests is that there
are live snails at the end of the test.
Note that a solution of household bleach does kill many invasive species
so it will remain a recommendation for general cleaning for invasive species.
A bleach solution will be good for parts of the country where New Zealand
Mudsnails are not present.
From a forum on the web: I use separate boots for separate regions. Small
price to pay.
A. Excellent. That is a good thing to do for waters
that you know are contaminated. I presume you are using a separate pair
of waders too. If not you should be sanitizing your waders before use
on other bodies of water. Mudsnails can be no bigger than a grain of pepper.
Testing has demonstrated that some snails are always missed during visual
inspection. Whirling disease spores are microscopic in size as is the
"Rock Snot" diatom. The young of zebra mussels are microscopic,
also. Thus visual inspection is not adequate.
Your other set of wading equipment that you use for waters that are not
known to be contaminated:
You need to be sanitizing them since you and everyone else are not going
to know that a body of water has recently become contaminated until months
or years after contamination. There are two major reasons:1) Things like
Didymo and Mudsnails are too small to notice in a stream or lake until
there is a substantial population in the water. The head biologist for
the Colorado DOW says that there could be 10's of thousand of New Zealand
Mudsnails in the water before anyone would notice them. 2) It takes a
long time to get the word passed to the public about the problem.
Comments and questions can be sent to me at wdtuweb@aol.com
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