Alex Mustard / Portrait of a male short snouted seahorse (Hippocampus hippocampus) in sea oak seaweed (Halidrys siliquosa). Devon, England, United Kingdom. British Isles. English Channel. North East Atlantic Ocean.

Nick Hawkins / Sugar kelp (Sacchinaria latissima) off Nova Scotia, Canada. September

SCOTLAND: The Big Picture / Kelp forest (Laminaria digitata) with small fish, Shetland, Scotland, UK, July.

Franco Banfi / Sugar kelp (Saccharina latissima) and Sea anemones (Actiniaria) on rock near iceberg. Tasiilaq, East Greenland. April.

Franco Banfi / Sugar kelp (Saccharina latissima) near iceberg, view upwards to gap in sea ice. Tasiilaq, East Greenland. April.

Sue Daly / Furbelows seaweed (Saccorhiza polyschides), with fronds moving in the current, Sark, British Channel Islands, UK, June.

Solvin Zankl / Thongweed (Himanthalia elongata) edible plant sold as 'Sea Spaghetti' for human consumption. From Roscoff, France, April. Preserved specimen.

Solvin Zankl / Kelp forest (Laminaria hyperborea), Atlantic Ocean, North West Norway, March.

Orsolya Haarberg,Orsolya Haarberg / Brown Algae (Fucus dustuchus) making patterns in snow and sand. Skagsanden beach, Nordland, Norway, February. Highly commended in Plants category of the GDT 2011 competition

Nick Upton / Common Shore crab (Carcinus maenas) on clump of Toothed wrack (Fucus serratus) exposed on shore at low tide, St. Bees, Cumbria, UK, July.

Robert Thompson / Bladder wrack seaweed {Fucus vesiculosis} Northern Ireland, UK

Ross Hoddinott / Bladder wrack (Fucus vesiculosus) seaweed, Sandymouth bay, Cornwall, UK. March