Juergen Freund / Sargassum seaweed (Sargassum sp) floating on the sea surface, Palawan, Philippines, May

Norbert Wu / Atlantic Spotted Dolphin (Stenella frontalis) playing with Sargassum weed, Little Bahama Bank, Caribbean

Nick Upton / Japanese wireweed / Japanese weed / Japweed (Sargassum muticum), an invasive species from the western Pacific spreading in Europe and the UK, buoyed up by air bladders in a rockpool, Wembury, Devon, U...

Juergen Freund / Sargassum seaweed (Sargassum sp) floating at the surface, split level, El Nido, Palawan, Philippines, May.

Juergen Freund / Sample of Brown algae {Sarcassum cf myriosystum} from Coral Reef census, Lizard Island, Queensland, Australia, April 2008. To store the algae, specimens are pressed and dried out in a herbarium press,...

Juergen Freund / Sample of Brown algae {Sarcassum cf myriosystum} from Coral Reef census, Lizard Island, Queensland, Australia, April 2008. To store the algae, specimens are pressed and dried out in a herbarium press,...

Robert Thompson / Sargassum seaweed {Sargassum muticum} Ballyhenry Point, Strangford Lough, County Down, Northern Ireland, UK, September

Robert Thompson / Sargassum seaweed {Sargassum muticum} Ballyhenry Point, Strangford Lough, County Down, Northern Ireland, UK, September

Adrian Davies / Japweed {Sargassum muticum} alien introduced species of seaweed, Prawle Point, Devon, UK

Norbert Wu / Sargassum Weed (Sargassum sp) growing on bottom will break off to form large floating patches of sargasso weed, Bahamas, Caribbean

GEORGETTE DOUWMA / Golden seahorse {Hippocampus whitei} amongst Sargassum weed, Sydney, Australia

GEORGETTE DOUWMA / Golden seahorse {Hippocampus whitei} amongst Sargassum weed, Sydney, Australia