The ringed-billed gull flew to the stream on the beach between 3 and 4 hours after high tide (c12:00pm on Thurs), and after a wash, flew off. The common gull with the green ring with white lettering that Derek saw was also present but I could only read the last two digits which were 17, the rest of the ring was always under the water, until it flew out of range. The redshank "A3" was present, ringed originally on 14/03/2016, and also seen on 05/02/2017, when "A1" was alongside.
The number of oystercatchers seemed lower than usual (c.30 present) though difficult to get an accurate figure because of disturbance both from humans and gulls. Every time one caught a worm it had to fly off, or it would have it stolen by a common gull. Even flying off didn't guarantee it got it's meal, as the act of flying drew attention to it, and half the gulls on the beach chased it. It was the same for curlews, though they seemed to have developed a way of swallowing their catch so quickly that the gulls were disappointed. The common gulls seemed to know this and preferred to be near an oystercatcher than a curlew. It struck me that gulls could perhaps have a far bigger influence on feeding oystercatchers than disturbance effects from dog walkers/bait diggers/birders?