In reply to Martin Haworth:
You probably know all this, but.......
Have you checked the BMC Access database?
If there are official restrictions they 'should' be listed there, although in this case it's not too helpful as at the moment it just says 'birds' (no species given) occasionally nest on the 'Wild Rover' section (i.e. next to Little Queenie).
Since it's not a regular nesting site, any restrictions aren't automatic by date, but only come into place if birds are actually nesting there (disturbing nesting birds is an offence even if not listed as restricted by BMC!), and it's still quite early in the year for anyone to have noticed whether they are there this year or not!
If you want a more definite answer I could try to contact some birders on Anglesey for you.
Post edited at 22:56