© CRAYAWAY 2013
American Signal crayfish often carry the crayfish plague (a.astaci), to which they are immune, but which kills
non-American crayfish within weeks. The crayfish plague had been a growing problem across Europe since the
late 19th century but was not understood properly. Crayfish-loving Sweden, having begun to suffer losses of
their native Noble crayfish, in the late 1960s imported American Signal crayfish which were known to be
immune to the plague. It was not understood that American crayfish were, nonetheless, potential carriers.
This soon became apparent, but not until American Signal crayfish had also been introduced to the UK by our
Government. As the Swedish project seemed to be going well, MAFF (Ministry of Agriculture, Forestry and
Fisheries) introduced American Signal crayfish to the UK in 1976.
It was expected that farming them, to supply the lucrative Scandinavian market, would create a good export
business, and grants were made available to encourage estate owners and aquaculturists to engage in the
project. Large quantities of American Signal crayfish were imported from Swedish stock and distributed to
hundreds of waters across England (and pursuantly to endless pet shops, fish tanks, fishmongers, and
If the Government had wanted to introduce a deadly national epidemic, they could not have made a better
job of it. Sure enough, over the last thirty years, the majority of our native White-clawed crayfish have been
wiped out. Unwittingly, MAFF had blindly rushed into causing an environmental disaster for the sake of an ill
thought out business plan. The new crayfish farms had to wait for at least four years before their first annual
harvest, by which time crayfish prices had dropped dramatically. Other countries had also seen the same
opportunity and places like China were now exporting very cheap crayfish.
In the UK there was suddenly such an abundance of crayfish that competition was strong and prices low. The
farms were soon competing with wandering trappers who sourced wild stock at a fraction of the farmed costs.
Under these conditions farming crayfish was uneconomical and most such businesses stopped. This resulted in
massive populations of crayfish being unmanaged and often given easy access to the wider environment as
sites were redeveloped. No serious action was taken by the Government to control the problem, while they
still stood a chance. Not surprisingly, the few advisers who understood the problem did not demand costly
action to clean up a mess that they had only just made. That would have drawn attention to errors,
questioned competence, demanded answers and fall-guys and scapegoats, etc.. If there was ever an
opportunity to control the crayfish, it was soon gone. It was deemed better to observe the crayfish problem
as it developed, and hold regular meetings to discuss the best way to deal with it.
Those meetings continue to this day.