No interactions present.
Are you sure this isn't bubbles of oxygen trapped in algae? Each one looks separate to me, rather than clumped together. They also look all different sizes, and I can't see any embryos...
Could be my eyes...
Hard to see for sure from the photo... They were in one small patch in the water.
Lat/Lng: 56.0181, -2.8551
OS grid ref: NT467809