Chris Gomersall / 2020VISION / Sanderling (Calidris alba) in winter plumage feeding on tideline, The Wash, Norfolk, March. Did you know? The Sanderling is the only British wading bird that has no back toe; this gives it a distincti...

Brent Stephenson / Steller's Sea Lions (Eumetopias jubatus) resting on rocks above the tideline. Zodiac with tourists watching in the background. The Brothers, Alaska, United States, July.

Roger Powell / Two Redshank (Tringa totanus) walking along the tideline, Boulmer, Northumberland, UK

Yva Momatiuk & John Eastcott / Gentoo Penguin (Pygoscelis papua) chick begging parent for food, on beach, fall, Gold Harbour, South Georgia Island, Southern Ocean, Antarctic Convergence

Tui De Roy / Green Sea Turtle (Chelonia mydas) female hauling out on beach, Bartolome Island, Galapagos Islands, Ecuador

Ernie Janes / Debris from the 2004 Tsunami amongst flowers above tideline in Southern Thailand

Chris Gomersall / 2020VISION / Sanderling (Calidris alba) adult in winter plumage vocalising on tideline and pausing to preen with its foot, The Wash, Norfolk, England, UK, March

Ernie Janes / Common sunstar (Crossaster papposus), Starfish (Asterias sp), Razor shells, crabs, clams and other seashells stranded on tideline after a storm, Norfolk, UK, November

Ernie Janes / Common sunstars (Crossaster papposus), Starfish (Asterias sp), Razor shells and clams stranded on tideline after a storm, Norfolk, UK, November

Ernie Janes / Mass of dead Seven-spot ladybirds (Coccinella septempunctata) on tideline, Norfolk, UK, August

Juergen Freund / A man and woman walking along the tideline of a white sandy beach. Daram Island, Misool, Raja Ampat, West Papua, Indonesia, January 2010.

Markus Varesvuo / Bar-tailed Godwit (Limosa lapponica) adult female hunting for food on tide line, Finland, July

Pete Oxford / Pacific Green Sea Turtle (Chelonia mydas agassizi) on beach, Cape Douglas, Fernandina Island, Galapagos Islands, Ecuador

Edwin Giesbers / Long-tailed / Crab-eating macaque (Macaca fascicularis) foraging on exposed tideline, Bako National Park, Sarawak, Borneo, Malaysia

Roger Powell / White-tailed eagle (Haliaeetus albicilla) feeding on carcass that has washed up on the tideline, Varanger Fjord, Arctic Norway. June

Roger Powell / White-tailed eagle (Haliaeetus albicilla) leaping along shoreline, Varanger Fjord, Arctic Norway. June

Roger Powell / White-tailed eagle (Haliaeetus albicilla) standing on seaweed detritus, on the tideline, Varanger Fjord, Arctic Norway. June

Roger Powell / Ruff (Philomachus pugnax) Reeve (female) feeding along the tideline, Varanger fjord, Arctic Norway. June

Roger Powell / White-tailed eagle (Haliaeetus albicilla) juvenile, feeding on carcass that has washed up on the tideline, Varanger Fjord, Arctic Norway. June

Roger Powell / Sanderling (Calidris alba) searching for food along the tideline, Boulmer, Northumberland, UK

Roger Powell / Sanderling (Calidris alba) running quickly across the tideline, Boulmer, Northumberland, UK

Roger Powell / Redshank (Tringa totanus) walking along the tideline, Boulmer, Northumberland, UK

Roger Powell / Three Redshanks (Tringa totanus) walking along the tideline, Boulmer, Northumberland, UK

Roger Powell / Redshank (Tringa totanus) walking along the tideline, Boulmer, Northumberland, UK

Roger Powell / Small flock of light-bellied Brent Geese (Branta bernicla hrota) flying to their roosting ground as high tide approaches, Holy Island, Northumberland, U.K.

Gary K. Smith / Tideline with mass of Razor shells (Ensis siliqua) washed ashore, Norfolk, UK, November 2009

Tom Marshall / New Zealand pipit (Anthus novaeseelandiae) at tideline, Ashley Estuary, Canterbury, New Zealand, July

Tom Marshall / White faced heron (Ardea / Egretta novaehollandiae) feeding on tideline, Kaikoura, New Zealand

Oriol Alamany / Beach, Zapadni Bay with Rush Point in the distance, Saint George Island, Pribilof Islands, Alaska, USA

Alan Williams / Knot (Calidris canutus) flock landing to join other waders at the tideline in winter plumage, Liverpool Bay, UK, November

Gary K. Smith / Razor shells {Ensis siliqua} washed up on tideline, Norfolk, UK, october.

Gary K. Smith / Sanderling {Calidris alba} running along tideline, North Norfolk, UK,

Roger Powell / Purple Sandpiper {Calidris maritima} at feeding area in rotting kelp, Varanger, Norway

Roger Powell / Purple Sandpiper {Calidris maritima} feeding in tidal pool, Varanger, Norway

Roger Powell / Common Gull {Larus canus} flying along high tideline feeding area, Varanger, Norway

Roger Powell / Turnstone {Arenaria interpres} walking through feeding area amongst bladderack seaweed, Varanger, Norway

Paul Hobson / Sanderling {Calidris alba} running along the tideline, Yorkshire, UK

Dave Bevan / Purple sandpiper (Calidris maritima) feeding amongst the rotting seaweed on tideline, UK

Dave Bevan / Common starling (Sternus vulgaris) feeding amongst rotting seaweed on tideline, UK

Dave Bevan / Kittiwake (Rissa tridactyla) collecting seaweed from beach for nest building, UK

Dave Bevan / Redshank (Tringa totanus) feeding on tideline, North Wales, UK, March

Dave Bevan / Redshank (Tringa totanus) feeding on tideline, North Wales, UK, March

Roger Powell / Drake Common Shelduck {Tadorna tadorna} walking along tideline, Lindisfarne (Holy island), Northumberland, UK

Roger Powell / Common Shelduck {Tadorna tadorna} female watching over feeding male, Lindisfarne (Holy island), Northumberland, UK

Dave Bevan / Rook (Corvus frugilegus) feeding at tideline on seashore, North Wales, UK, February

Steve Knell / Purple sandpiper {Calidris maritima} standing on tideline. Norway, 2006

Ingo Arndt / Common Seal (Phoca vitulina) resting in shallow water, North Sea, Helgoland, Germany

Rolf Nussbaumer / Long-billed Curlew (Numenius americanus) eating crab, Padre Island National Seashore, Texas, USA. December 2001

Pete Oxford / Galapagos Sea Lion (Zalophus wollebaeki) at shoreline, vulnerable, Gardner Bay, Espanola Island, Galapagos Islands, Ecuador

Pete Oxford / Galapagos Sea Lion (Zalophus wollebaeki) at shoreline, vulnerable, Gardner Bay, Espanola Island, Galapagos Islands, Ecuador

Pete Oxford / Sally Lightfoot Crab (Grapsus grapsus) in rock crevice near tideline, Santiago Island, Galapagos Islands, Ecuador

Pete Oxford / Sally Lightfoot Crab (Grapsus grapsus) in rock crevice near tideline, Santiago Island, Galapagos Islands, Ecuador

Tim Fitzharris / Storm cloud over beach, Canaveral National Seashore, Florida

Jose B. Ruiz / Neptune grass {Posidonia oceanica} washed up on beach. Spain Mediterranean

Norbert Wu / Oil spill clean up on beach, Huntington Beach, California

Norbert Wu / Oil spill on beach, Huntington Beach, California