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Dear Astacologists,

I have recently found that the Ministry of Agriculture, Forestry and
Fishery of Japan (MAFF) considers three species of crayfish (Cherax
tenuimanus, C. quadricarinatus, Astacus leptodactylus) are exempt from the
list of "noxious animals" in the Plant Protection Act. This means that one
can legally import live crayfish of these species to Japan. A part of the
reason is that there seems to be no scientific evidence of their hazardous
impacts on aquatic plants. Another, but more convincing reason is that
there seems to be a force from pet/aquarium industries. I am trying to
convince that importation of live crayfish are dangerous regardless of
species because they are omnivores, ecosystem engineers and/or transmitters
of disease and parasites. Unfortunately, impacts on biodiversity is out of
the scope of the Plant Protection Act.

Ideally, importation of live animals such as crayfish should be regulated
through an act that concerns impacts on biodiversity rather than on mere
agricultural plants. Starting from June 2005, Ministry of the Environment
of Japan is going to place the Invasive Species Act that regulates live
import, aquarium trade, possession and/or breeding for the specified,
invasive alien species. This act concerns alien impacts on biodioversity,
human health and/or economic damage. However, an important aspect of this
act is that eradication will be obliged for the listed species. As far as
crayfish are concerned, only signal crayfish (Pacifastacus leniusuclus) is
going to be discussed as a candidate. Red swamp crayfish, which are
already prevalent throughout the Japanese archipelago, would not be
considered.