Threat from the aliens

I FIND it rather worrying that our rivers appear to have received an influx of alien species.

Several reports have surfaced to suggest that catfish and sturgeon have been banked from a number of rivers, and this is alarming.

These fish do not belong in our waterways and if they breed successfully they could have a disastrous effect on our rivers.

Any stillwaters that have them stocked must make sure there is absolutely no way these fish could escape – through flooding, for example – and anyone caught illegally slipping the odd fish in should be severely dealt with. Brian Gordon, Preston