AROUND the canal at Farnhill there are frequent sightings of mink and American Signal Crayfish (Craven Diary, September 30).

My girlfriend’s dog greedily crunches up any leftovers of crayfish on the canal towpath. So plentiful are the crayfish, I have heard fishermen complain about them attacking the bait on hooks.

The other day, we spotted a mink busily chomping on a crayfish in a crevice next to Milking Hill swing bridge.

Both are introduced, and very invasive species. This must be a rare example of an introduced invasive species, higher up the food chain predating on another?

Before I moved here in 2016, I became acquainted with a bloke who used creels to catch these crayfish in the River Great Ouse near Olney (famous for the annual pancake race). They were then processed and dispatched to a ready market in Sweden. Now there’s a thought!

John Van der Gucht

Cross Hills