Mixenden

Photos taken late morning of a couple of the birds mentioned by Dave.
It's a 'Continental' cormorant, P. c. sinensis. The rear edge of the bare yellow skin drops vertically from the gape.

(Vinicombe et al in the Helm guide to Bird Identification, 2014, say that the shape of the 'gular patch' is the only way confidently to separate the two races).