Norbert Wu / Oceanic White-tip Shark (Carcharhinus longimanus) with Pilot Fish (Naucrates ductor), Bahamas, Caribbean

Andy Rouse / Manta ray (Manta birostris) swimming on ocean floor Coral Bay, Australia

Alex Mustard / Diver blowing bubble rings, while resting on the sand, East End, Grand Cayman, Cayman Islands, British West Indies, Caribbean Sea, January 2011.

Juergen Freund / Outrigger boat in Big Lagoon, with its karst limestone cliffs, emerald waters and shallow coral reefs in the white sand. North Palawan, Philippines, May 2009.

Juergen Freund / Aerial view of coral cays and white sand bars surrounding Bugsuk Island, Farm 1 of Jewelmer pearl farm. This private island has been highly protected since the 1970's and is in pristine environmental...

Juergen Freund / Aerial view of coral cays and white sand bars surrounding Bugsuk Island, Farm 1 of Jewelmer pearl farm. This private island has been highly protected since the 1970's and is in pristine environmental...

Juergen Freund / Aerial view of a coastal island with white sand beaches, Palawan, Philippines, May 2009.

Daniel Heuclin / Rio Grande Cottonwood tree (Populus fremonti wislizenii) on a sand "pedestal" White Sands National Park. New-Mexico, USA, August 2009

Floris van Breugel / View of snow-like dunes of the White Sands National Park. These sand grains consist of tiny crystals of gypsum. New Mexico, USA, April 2010

Alex Mustard / Tiger shark (Galeocerdo cuvier) portrait over white sand. Little Bahama Bank, Bahamas.

Alex Mustard / A lone Caribbean reef shark (Carcharhinus perezi) cruises over sand ripples. Walkers Cay, Northern Bahama Islands, Republic of Bahamas.

Solvin Zankl / These hatchlings of an Olive ridley sea turtle (Lepidochelys olivacea) should be buried and protected under 40 cm of warm sand, but a domestic dog dug them out at Ostional beach in Costa Rica. Novembe...

David Woodfall / Shelduck (Tadorna tadorna) moulting birds at high tide roost, Bridgewater Bay NNR, Severn estuary This is a nationally significant site for this species, Somerset, England, August 2009

Rob Tilley / White sand dunes against blue sky, White Sands National Park, New Mexico, USA, February 2009

Rob Tilley / White sand dunes against blue sky, White Sands National Park, New Mexico, USA, February 2009

Rob Tilley / White sand dunes against blue sky, White Sands National Park, New Mexico, USA, February 2009

Jouan & Rius / White sand dune in Mungo National Park, New South Wales, Australia

Niall Benvie / Sand spurrey flower {Spergularia rubra} Spain

Solvin Zankl / Dancing White Lady Spider (Leucorchestris arenicola) 'dancing' in defensive threat display on sand dune, Namib Desert, Namibia

Jouan & Rius / Antelope footprints in the white sand, Kalahari desert, South Africa

Albert Lleal / Electron microscope view of bryozoan colony fragment isolated from beach sand, Formentera, Balearic Islands, Spain

Juergen Freund / Woman's bare legs and feet on white sand, Broome's Cable Beach, Western Australia

Luiz Claudio Marigo / Negro river with beach of white sand, Sao Gabriel da Cachoeira, Amazonas, Brazil

Flip Nicklin / Sandbar Shark (Carcharhinus plumbeus) underwater portrait, bottom-dwelling coastal species, worldwide distribution

Konrad Wothe / Coral reef in lagoon surrounded by white sand beaches and palm trees, Rani Island, Irian Jaya, Indonesia

Fred Bavendam / Whitemargin Stargazer (Uranoscopus sulphureus) lying buried in sand where it waits to ambush prey, Lembeh Strait, Indonesia

Flip Nicklin / Oceanic White-tip Shark (Carcharhinus longimanus) underwater portrait, North America

Gavin Hellier / Tropical sea and beach, Seychelles, Indian Ocean

Juan Manuel Borrero / Illustration of Hirundinidae family: Common Sand Martin (Riparia riparia), Northen House-Martin (Delichon urbicum), Common Swift (Apus apus) and Barn Swallow (Hirundo rustica). Pencil and watercolor p...

Tim Fitzharris / Sand dunes, White Sands National Park, New Mexico

Tim Fitzharris / Sand dunes, White Sands National Park, New Mexico

Norbert Wu / Oceanic White-tip Shark (Carcharhinus longimanus), Bahamas, Caribbean

Norbert Wu / Oceanic White-tip Shark (Carcharhinus longimanus), Bahamas, Caribbean

Norbert Wu / Oceanic White-tip Shark (Carcharhinus longimanus), Bahamas, Caribbean

Norbert Wu / Oceanic White-tip Shark (Carcharhinus longimanus), Bahamas, Caribbean

Norbert Wu / Oceanic White-tip Shark (Carcharhinus longimanus) with Pilot Fish (Naucrates ductor), Bahamas, Caribbean

Norbert Wu / Mangrove (Rhizophoraceae) and Eelgrass (Zostera sp) provide shelter for young fish, Bahamas, Caribbean

Norbert Wu / Mangrove (Rhizophoraceae) and Eelgrass (Zostera sp) provide shelter for young fish, Bahamas, Caribbean

Floris van Breugel / Darkling Beetle (Tenebrionidae) on sand in White Sands National Park, New Mexico, USA, April.

Solvin Zankl / The white carbonate sand from Raja Ampat, Indonesia, is generated by a vast diversity of organisms: e.g. foraminifera, sponges, brachiopods, echinoderms, bryozoa and mollusks. Diagonal of frame approx...

Solvin Zankl / Handful of white sand from a beach in Raja Ampat, Indonesia, consists to a large extent of skeletal parts of small animals or even plants.

Tom Vezo / Evening Primrose (Oenothera sp) flowers in desert, Joshua Tree National Park, California

Tom Vezo / Evening Primrose (Oenothera sp) flowers in desert, Joshua Tree National Park, California

Enrique Lopez-Tapia / Golden wheel / Cartwheeling spider (Carparachne aureoflava), Namib desert, Namibia, November

Konrad Wothe / Gypsum in sand dunes, Erg Murzuk, Libyan desert, Libya, Sahara, North Africa, November 2007

Konrad Wothe / Camargue horses (Equus caballus) walking along sand dunes, Camargue, France, April

Hanne & Jens Eriksen / Dromedary / Arabian camel (Camelus dromedarius) flock in sand desert amongst the dunes, UAE, December.

Daniel Heuclin / Bleached earless lizard (Holbrookia maculata ruthveni) camouflaged on sand, White Sands National Park, New Mexico, USA, May

Daniel Heuclin / Sand Verbena (Abronia angustifolia) White Sands National Park, New Mexico, USA

Konrad Wothe / Soaptree Yucca (Yucca elata) flowering on gypsum dune field, sunset, White Sands National Park, New Mexico, USA, November

Konrad Wothe / Soaptree / Yucca (Yucca elata) flowering on gypsum dune field, White Sands National Park, New Mexico, USA, November

Philippe Clement / Pholadidae on beach showing Common piddock (Pholas dactylus), American piddock (Petricola pholadiformis) and White piddock (Barnea candida) shells, Normandy, France

Philippe Clement / White furrow shell (Abra alba) on beach, Belgium

Philippe Clement / Common whelk (Buccinum undatum) shells on beach, Brittany, France

Jim Brandenburg / Lesser Earless Lizard (Holbrookia maculata), White Sands National Park, New Mexico

Kirkendall-Spring / Sand dunes on Saint Simons Island, Georgia, USA, October 2008

Kirkendall-Spring / Sand dunes on Saint Simons Island, Georgia, USA, October 2008

Ernie Janes / Grey seal (Halichoerus grypus) pup on sand dune, Norfolk, UK, December

Ernie Janes / Common seal (Phoca vitulina) on beach under wooden structure, UK

Rod Williams / Black-backed Magpie (Gymnorhina tibicen) Burleigh Heads, SE Queensland, Australia, March

Juergen Freund / Aerial view of coastal island with white sand beaches, Palawan, Philippines, May 2009.

Nick Upton / White limestone cliffs with sections that have collapsed into the sea. "Le Grain de Sable" (grain of sand) sea stack is central. Bonifacio, southern tip of Corsica, France, May 2010.

Nick Upton / White limestone cliffs with sections that have collapsed into the sea. "Le Grain de Sable" (grain of sand) sea stack is to the right. Bonifacio, southern tip of Corsica, France, May 2010.

Juergen Freund / Aerial view of Coastal island with white sand beaches and limestone face cliffs, Philippines, May 2009.

Juergen Freund / White sandy beach of one of the Raja Ampat islands. Raja Ampat, West Papua, Indonesia, February 2010.

Juergen Freund / Thorny seahorse (Hippocampus hystrix) hiding by a similarly-coloured sponge. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / White sandy beach of one of the Raja Ampat islands. Raja Ampat, West Papua, Indonesia, February 2010.

Juergen Freund / Humpback / Devil scorpionfish (Scorpaenopsis diabolus) on the sand. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Threadfin sand diver (Trichonotus elegans) swimming over seabed, Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Longspine waspfish (Paracentropogon longispinus) on the sandy sea bed. Lembeh Strait, North Sulawesi, Indonesia.

Juergen Freund / Leatherback turtle (Dermochelys coriacea) egg on the sand. Warmamedi beach, Bird's Head Peninsula, West Papua, Indonesia, July 2009.

Juergen Freund / Beautiful blue and white Nudibranch (Chromodoris kuniei) on the sand. Lembeh Strait, Sulawesi, Indonesia

Daniel Heuclin / Discarded drinks cans / litter on the sand. White Sands National Park, New Mexico, USA

Daniel Heuclin / Discarded drinks cans / litter on the sand. White Sands National Park, New Mexico, USA

Daniel Heuclin / Little white whiptail lizard (Cnemidophorus inornatus) moving through sand, White Sands National Park. New-Mexico, USA Controlled conditions.

Daniel Heuclin / Dune Darkling beetle (Eleodes suturalis) in head-stand posture, White Sands National Park, New-Mexico, USA

Daniel Heuclin / Rio Grande Cottonwood tree (Populus fremonti wislizenii) on a sand "pedestal" White Sands Natinal Monument. New-Mexico, USA, August 2009

Robert Thompson / Aerial view of Cruit Island Lower and the Rosses, County Donegal, Republic of Ireland, September 2009

Angelo Gandolfi / Weedy Dogfennel (Chamaemelum mixtum) flowering on seashore, Italy, May 2010

Angelo Gandolfi / View of the white cliffs of Bonifacio. The large boulder (right) fell from the main block 800 years ago. It's called "grain de sable" (grain of sand). Corsica island, France, February 2010

Christophe Courteau / White Impala (Aepyceros melampus) not an albino, just an unusual pale form, Sabi Sand Private Game Reserve. South Africa, June

Christophe Courteau / White rhinoceros (Ceratotherium simum) calf in bush, Sabi Sand Private Game Reserve, South Africa, June

Christophe Courteau / White rhinoceros (Ceratotherium simum) calf in bush, Sabi Sand Private Game Reserve, South Africa, June

Gerrit Vyn / Oil spill response vehicles grooming a white sand beach before sunrise. Many clean up efforts from the BP Deepwater Horizon oil leak were cosmetic in nature and aimed to cover up the damage. These veh...

Michele Westmorland / White sand beach at Grace Bay, with people sea kayaking, Provodenciales Island, Turks and Caicos, Caribbean. June 2007.

Robert Thompson / White rocks, Portrush, North Antrim coast, County Antrim, Northern Ireland, UK

Georgette Douwma / Burrowing sea cucumbers (Neothyonidium magnum) one white and one black, buried deep in the sand, feeds by filtering the water column with its tentacular crown, successively bringing each arm into its...

Jouan & Rius / White Sand beach in Exmouth peninsula, Coral coast, Western Australia. July 2009

Jouan & Rius / White sand beach in Exmouth peninsula, Coral coast, Western Australia. July 2009

Jouan & Rius / Splendid everlastings (Helipterum splendidum) flowering in red sand, within dry semi-desert, Murchison valley, Western Australia. August 2009

Jouan & Rius / Splendid everlastings (Helipterum splendidum) flowering in red sand, within dry semi-desert, Murchison valley, Western Australia. August 2009

Jouan & Rius / Splendid everlastings (Helipterum splendidum) flowering in red sand, Western Australia. August 2009

Jouan & Rius / Splendid everlastings (Helipterum splendidum) flowering in red sand, within dry semi-desert, Murchison valley, Western Australia. August 2009

Jouan & Rius / Splendid everlastings (Helipterum splendidum) flowering in red sand, Western Australia. August 2009

Pete Oxford / White-fronted capuchin monkey (Cebus albifrons) foraging in the sand for food, Puerto Misahualli, Amazon rainforest, Ecuador, South America

Aflo / Rear view of two Atlantic spotted dolphins (Stenella frontalis) just below the surface, White Sand Bank, Bahamas