While I was in Finland this year, I found some crayfish in the lake where my uncle's cottage is. There was a disease years ago that killed almost all the crayfish in the area. The lake my grandmother's cottage is at still doesn't seem to have gotten the crayfish back, even though the two lakes are connected. Anyways, I found a whole bunch of crayfish at the other lake, so I was happy they're coming back. Oddly, some of the crayfish I caught were almost all blue. It was pretty cool finding blue crayfish in the lake. Most of them are a grayish brown.

Dont suppose you took any pictures did you ?

I can't remember if I did. I have a feeling I did take some. I'll have to check the pictures from this summer.

I couldn't find any pictures. I don't think I had a camera with me when I found the crayfish. I'm pretty sure the species was Astacus astacus. It's one of the two native species in Finland. The other native species is Astacus leptodactylus, and Pacifastacus leniusculus is an introduced species. It was the American crayfish plague that killed a lot of the native crayfish. The introduced species was more resistant to the plague though. I just found this on a Finnish site about the crayfish species in Finland. "Jokiravun väritys vaihtelee tumman ruskean, mustan, vaaleanruskean, sinisen, punaisen ja jopa valkean välillä, riippuen jokiravun elinympäristöstä ja ravinnosta." It translates into, "The European crayfish's (European, noble, or broad-finger crayfish are the common names in English. "river crab" is the literal translation of "jokirapu") coloring changes from dark brown, black, lightbrown, blue, red, and even white, depending on the crayfish's habitat and what it eats." I couldn't find anything about the other two species being blue. The crayfish I found also looked more like Astacus astacus than the other species. I was happy to see any crayfish at all in the lake. I've never caught any crayfish there before. My uncle did see some before though. Maybe the the crayfish will start to appear more often now.

Glad you translated that for me/us Yes it would be nice to think that the native crayfish can repopulate the lake. Just goes to show why we should never introduce any species that is not native to the enviroment/country, as more often than not a native species will allways suffer

Such as the Normans into England ?

And the yob that brought eight rabbits over here, and was very pleased with himself, when a short while later, he was able to go outside and shoot thousands of them every week !

Cane Toads.

Cats.

Dogs to an extent.

Guppies (sort of).

European Carp.

Star Fish is the current threat here. Introduced via the purging of ships ballast.

And right now, several species of Jelly Fish are popping up from Australia up into upper S.E.Asia, where they've not been seen before. Attributed to the tsunami, and it's effects on ocean currents.

Several coastal locations in Malaysia, during December, reported un-identified 'pods' washing up on shore.