@Gazza, bumping this up as I took a side-scan screenshot of bream nests over the weekend and thought I'd update this thread.
Here you can clearly see the bream nesting sites showing as circular, honeycomb-like structures on the right hand side of this sonar pass. I was scouting around for a new mark on the weekend as my regular spots were already taken. As soon as I spotted these I dropped a line over and bingo! Fish first drop.
Full report over on Outlaws in case you want to read it: https://www.offshoreoutlaws.co.uk/topic/2357-may-14th-on-the-bream/