another fine mess.....

Peter Hughes (peterh at pican.pi.csiro.au)
Mon, 15 Jul 1996 13:11:49 +1000 (EST)

Hello again

Sorry for the absence Peter, I just had relatives here for the weekend
and as such did not come in to work on the weekend. I must say that I did
not think that this topic would take up so much bandwidth, however I do
feel that it is important.

Ok to the nittye gritty:

Bruce

I would love to be able to summarize the results of the disease survey.
However what was published was 600pgs of summary itself and thus does not
really lend itself to being summarised again, except in very general
terms that are vague. Each disease is neatly summarised as to what makes
it a potential problem or not and the individual factors which make up
the composite index (ie virility, spreadability, species specificity,
etc). I am very pushed for time at the moment and would be unable to do
such for a long time (I have the thesis I am doing to write together
with a few papers as well).

What should caution people is what diseases that we have already had
escape and cause havoc. The discus/angel disease made it here despite the
quarantine procedures. I had my two lovely gold marble angels die because
of that. The second is a die off of yellow belly in the murray that is
documented in a book we have in our library. A disease of a non related
species killed of a lot of these fish simply because our native fish had
not developed resistance to it. The disease was not pathogenic on the
original host (goldfish from memory) but was very happy on the
yellowbelly. That is one type of interaction that does require research,
because perfectly happy healthy fish can have a disease that kills off
other fish and not touch themselves.

As for selecting a virus that hits gambusia specificaly, one may exist
however it would take a lot to find it and then the years of research
needed to show that it would not harm our native fish populations would
make that a long task. Some hope might come if someone used an innocous
virus that had been transformed with something that would make the
females or males sterile. An approach like that is being trialled for
foxes here. It was to be released about the same time as the callici
virus so that the foxes did not cause too much destruction of native
wildlife. (I will not at present mention my extreme distaste for cats,
especially feral ones).

One thing that I think makes the translocation arguement a bit less of an
issue is that the streams that are most likely to have fish released in
them are the ones that are already degraded. That is the streams that are
in our urban waterways, the ones with the weather loaches, gambusia, carp
and not much else. The deliberate releasing of fish in other areas is not
going to be controllable at any stage because it is something that people
will do for strange reasons. There is an ANGFA ACT member who recently
put gambusia into his farm dam so that he would have a ready source of
feeder fish for his aquarium fish. In cases such as this I am not sure if
the local populations are viable anymore, of course this then leads to
the arguement that they should be put under as little further stress as
possible and as such no more introductions should be made.

Barry

I am not sure what this "Vegemite award" is, perhaps you could clarify
that one?

My final comment will be this, I started this thread to make people aware
that there is more to illegally importing things than the simple wish to
have it. The amount of traffic on this list is testimony to that. What I
wanted to say was this, despite the dispute over the
hybridisation/translocation/survival in the wild arguements, there is
still the possibility that the apparently healthy stock that the person
has will harbour something that will in the future kill off other fish.
At least if some authority has examined the "catch", you have done as much
as what can be done and if a problem ensues you can always say that you
did the right thing at the time. I think that most ANGFA members are
reasonable people interested in the fish that they keep and would not
like to think that their actions may lead to the destruction of even a
single species of endemic fish.