In amongst Frogbit (flowers provide scale). I'd welcome an identification.
No interactions present.
I have these in my garden pond, (posted earlier in the year), but they're multicoloured there. The shape looked right, but the colour wrong: so thanks again for solving this one.
NB you've given the habitat as marine, it seems
Senior moment there: will edit it now.
Lat/Lng: 52.4515, -0.1889
OS grid ref: TL231852