MYN / Carsten Krieger / Sea Lettuce (Ulva lactuca) on Common Limpet (Patella vulgata) from tide pool, County Clare, Republic of Ireland, December. Meetyourneighbours.net project

MYN / Carsten Krieger / Sea Lettuce (Ulva lactuca) on Common Limpet (Patella vulgata) from tide pool, County Clare, Republic of Ireland, December. Meetyourneighbours.net project

MYN / Carsten Krieger / Sea Lettuce (Ulva lactuca) from tide pool, Carageen, County Clare, Republic of Ireland, December. Meetyourneighbours.net project

MYN / Carsten Krieger / Sea Lettuce (Ulva lactuca) from tide pool, County Clare, Republic of Ireland, December. Meetyourneighbours.net project

Nick Upton / Sea lettuce / Green laver (Ulva lactuca) growing in a rockpool alongside Coralweed (Corallina officinalis). Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Sea lettuce / Green laver (Ulva lactuca) growing in a rockpool alongside Coralweed (Corallina officinalis). Rhossili, The Gower Peninsula, UK, July.

Nick Upton / Common brittle star (Ophiothrix fragilis) well camouflaged among mix of red and green algae including Coralweed (Corallina officinalis), Harpoon weed (Asparagopsis armata) and Sea lettuce (Ulva lactuc...

Nick Upton / Gametophyte of Harpoon weed (Asparagopsis armata), an invasive red alga attached with barbed branchlets to Sea lettuce (Ulva lactuca) in a rockpool low on the shore, near Falmouth, Cornwall, UK, Augus...

Nick Upton / Red hornweed (Ceramium virgatum) growing in a rockpool low on the shore alongside Coralweed (Corallina officinalis) and Sea lettuce (Ulva lactuca), Wembury, Devon, UK, August.

Nick Upton / Netted dog whelks (Nassarius reticulatus) scavenging on rocks among Sea Lettuce (Ulva lactuca) and Irish moss / Carrageen (Chondrus crispus) seaweeds exposed on a low spring tide, Rhossili, The Gower...

Nick Upton / Colourful mix of Bushy rainbow wrack (Cystoseira tamariscifolia) with turquoise iridescent tips to its fronds and red Harpoon weed (Asparagopsis armata) surrounded by Coralweed (Corallina officinalis)...

Nick Upton / Bloody Henry starfish (Henricia oculata) exposed on a low spring tide on rocks next to a clump of Sea lettuce (Ulva lactuca) Crail, Scotland, UK, July