Mysterious white blobs all over algae reef in devon, UK.

[Bexy]

Can anyone help me with this identification dilemma?

The white blobs in this picture are absolutely everywhere on the bedrock reefs outside of Plymouth, UK. Does anyone have a clue what they are? They almost look colonial but colonies never appear larger than seen here (approx 2-3cm) while individual blobs seem to be literally everywhere, though often aggregating in dense patches. They seem to be attached to the substrate, algae,... practically anything!

I've only encountered them on photic (algae dominated) reefs at around 20m depth. I'm stumped! Any clues??

 

[Jim Greenfield]

Suggest you post this on the site of Marine Wildlife of the NE Atlantic:
Glaucus : Marine Wildlife of the NE Atlantic
There are some pretty clued up people specialising in "green water" that contribute to the site and should be able to help
Best of luck

 

[Rick Murchison]

At this resolution they look like Tunicate colonies, but without a closer look I can't say for sure.
Rick

 

[Bexy]

Jim, thanks I've taken your advice and made a post on Glaucus.

Rick, I think they look like colonial tunicates also, I'm just amazed at how prolific they are if that is what they are...

 

[livi120]

Just a guess here, no solid idea really, but to my eyes on the first closer picture they look like whelk egg-cases but much much smaller. Can they be the ribbon/coil like egg-cases of some small marine snail that likes to feed on this algae?

 

[Rick Murchison]

... egg-cases ...

I think that's the next most probable thing. We just need a better picture
Rick