Sargassum muticum

Rob Spray Overdue short edit of the dive around the oyster raft to check out the site before the survey... lots of weed and squirts!

Pamela Stephens Facebook This is just a message to say how very nice it was to see you both on Dawn's birthday. I was wrong about the broadcast in the morning - the comic thing was part of woman's hour. It was just by accident I chose this e-mail of yours to reply to. I wanted to report that we signed a petition about the protection of some of the Suffolk coast to be presented next year. I have doubts about my computer skills so I won't write too much. Love M xxx

Jens Christensen Hi Rob. Interesting construction, and video. How long has it been sitting in the water, and what camera did You use for this video?

Jens Christensen Seems to be a lot of Sargassum muticum on the mooring of the construction. Is it as abundant on the Seefloor?

Rob Spray I'd guess this raft was 5+ years old but may be recovered for maintenance annually so its true age might be hard to establish. This was filmed using a Canon HF200 HD camcorder. The seafloor can be seen in the part 2 and 3 videos. Some sargassum down there but not very much.

David Kipling Very squirty, as you say! Floating man-made structures seem perfect for them - clean surface for planktonic larvae to settle on, little by way of predation being raised up off the seabed (although I notice a crab or two had swum onto it!), and being designed for oysters presumably stuck somewhere with a nice gentle current to keep them fed. Loads of Styela clava. At about 4 min in there is a good shot of a colonial ascidian (I assume, unless it's a dripping sponge of some form) with a rather worryingly pendulous growth habit. What is it? It reminds me of the pictures of Didemnum vexillum I've seen (eeek!). http://www.marlin.ac.uk/PDF/Aliens_2.pdf

David Kipling Indeed - so what does Rohan Holt think it is?

Rob Spray a Diplosoma... no full guess :-(

David Wilson There seems to be much more Sargassum muticum in Poole Harbour this year. More than I ever remember seeing before. Has this been noticed anywhere else?

Paul Semmens Seems there's a lot more of it here in West Cornwall as well. Its almost fills some rockpools.