Country diary: Nature red in tooth and – quite literally – claw | Charlie Elder

River Culm, Devon: I joined a search for white-clawed crayfish, whose disastrous decline has taken place out of sight, but not out of mind

The river unwinds beneath overhanging trees, its broad back gently massaged by submerged knuckles of rock and trailing fingers of vegetation. Wading into the shallows, the conservationists James Maben and Charly Mead search amid tangles of tree roots and pull up short lengths of black plastic tubing bound together like oversized panpipes. They peer into the black cylinders, before emptying the silty contents into a bucket.

So far this morning the riverbed traps along this stretch of the River Culm have drawn a blank. But this time we are in luck. There in the bucket, resembling a little brown lobster, is a crayfish. More importantly, a white-clawed crayfish – and one that could help secure a future for this threatened freshwater species.