Alien Species Invading The British Isles

“An armor-plated alien invader is eating its way through wildlife in Britain’s waterways”
So reads The Daily Telegraph this week. Who said that environmental journalism can be dull?
The invader in question is the American Signal Crayfish (pictured), described as a six inch long killing machine and voracious predator that has already annihilated the native White Claw species, and now threatens to completely overwhelm many fragile aquatic eco-systems.
The problems started during the 1970’s when Signal crayfish bread in farms for the restaurant trade managed to escape. So successful have they been, with their lack of natural predators, rapid breeding rate, and willingness to eat absolutely everything including plants, insects, fish, snails, detritus and their own young, that they have quickly grown into an aquatic army of almost plague proportions.
- » See also: #4 Copenhagen, Denmark: Great Bicycle City Photo Tour
- » Get EcoWorldly by RSS or sign up by email.
River banks, already under pressure from flooding (and interest rates - sorry), are beginning to collapse as the crayfish burrow up to three feet into the banks, laying more than 250 eggs at once. At the same time, the fact that absolutely everything is on the Signal’s menu means that all other species effectively face the firing squad when the Signal crayfish arrives, either by land or water - the Signal can walk for several miles on dry land in search of new killing zones.
This all sounds nasty enough, but what surprised me even more is just how large the problem of species invasion has become. The Guardian has a short slide-show of foreign invaders, and introduced-species.co.uk is currently tracking 91 different invasive species and their impacts on native eco-systems.
What can we do about this? Not very much it seems. Every time mankind tries to manipulate our environment we usually seem to make a huge mess. Scientists are currently considering plans to breed large numbers of sterile male crayfish, releasing them into the world to upset breeding rates - probably not a bad plan, although adding even more of the monsters to the population does appear risky in the short term.
As usual, the problem comes down to ourselves, the original invasive species. One day we might find a way to stop making these mistakes, but until then we’ll just have to live with the consequences of our good intentions. At least crayfish taste good.
Image credit: david.nikonvscannon at Flickr under a Creative Commons license









Great pic!
I always wonder, who’s to say that we aren’t programmed to introduce these new species? The assumption that man is somehow separate from, and a negative influence on nature strikes me as at best bizarre; at worst it ignores the teachings of just about every religion, science and philosophy known to man.
The assumption stands firmly on the ground of another assumption; that we have free will. Since that subject is far too complex for a comment, I thought I’d just note that the grey squirrels mentioned in the Guardian pics link you gave are themselves being threatened by black squirrels… see http://www.guardian.co.uk/environment/2008/apr/26/endangeredspecies
Thanks for your thoughts Matt..
The only distinction I can draw is that most species tend to live as a part of nature as an integral part of its systems, giving and taking as nature’s systems constantly change and adjust. Humans, on the other hand, don’t live as part of nature, rather we tap it as a resource. Or at least this is what we have done since the dawn of the industrial revolution (which was a great thing for us)..
But we are about to digress into a whole new blog post here…
An armor-plated alien invader is eating its way through wildlife in Britain s waterways
The problems started during the 1970 s when Signal crayfish bread in farms for the restaurant trade managed to escape. So successful have they been, with their lack of natural predators, rapid breeding rate, and willingness to eat absolutely everything including plants, insects, fish, snails, detritus and their own young, that they have quickly grown into an aquatic army of almost plague proportions.
What can we do about this? Not very much it seems. Every time mankind tries to manipulate our environment we usually seem to make a huge mess. Scientists are currently considering plans to breed large numbers of sterile male crayfish, releasing them into the world to upset breeding rates - probably not a bad plan, although adding even more of the monsters to the population does appear risky in the short term.
Yes, some bright fool thought WoW, I can raise these mud bugs , cook them and make a fortune and they never once thought that the Crayfish lives in ditches or any other damp place and reproduce like mad, they eat like crazy and all it takes is one slip and poof they escape back into nature and take over the kingdom.
Congratulations once more humans, again you mess with nature out of greed and pay the price…
Nuff Said…..
StarDust
Nice pic but afraid it’s not an American Signal Crayfish freshwater, that’s a saltwater species, go to the Environment Agency website to get all the info.
Let the real predators in Britain have at ‘em! Tell humans where, when and how to catch and eat them and put no limits on the catch. The problem will soon rectify itself when the real predators are let loose!