An algae-clad stone groyne at Mudeford, Dorset, England, United Kingdom, Europe

The rocky shore of West Weares on Portland, looking towards Chesil Beach, Jurassic Coast, UNESCO World Heritage Site, Dorset, England, United Kingdom, Europe

Traditional sea salt production, Salinas de Janubio, Lanzarote, Canary Islands, Spain, Atlantic, Europe

Water rich in blue-green algae (cyanobacteria), mineral salts and fine silica mud at the geothermal spa that owes its existence to the Svartsengi geothermal power plant, Blue Lagoon, near Reykjavik, Iceland, Polar Regions

Water rich in blue-green algae (cyanobacteria), mineral salts and fine silica mud at the geothermal spa that owes its existence to the Svartsengi geothermal power plant, Blue Lagoon, near Reykjavik, Iceland, Polar Regions

Water rich in blue-green algae (cyanobacteria), mineral salts and fine silica mud at the geothermal spa that owes its existence to the Svartsengi geothermal power plant, Blue Lagoon, near Reykjavik, Iceland, Polar Regions

Rocks at Castle Sands in St. Andrews, Fife, Scotland, United Kingdom, Europe

Vibrant pink water lily blooming in a tranquil pond with green algae and lily pads, reflecting serene beauty in nature at Kew Gardens, London, England, United Kingdom, Europe

The intertidal zone of the Quantock Coast, West Somerset, contains an abundance of geology and wildlife. It is a Site of Special Scientific Interest (SSSI) and is of international geological importance.

A rocky shoreline covered with clusters of blue-black mussels. The mussels cling tightly to the rocks, creating a textured surface. Some green algae is visible in the water pools among the rocks, reflecting sunlight.

Aerial of San Antonio church, Island of Mozambique, UNESCO World Heritage Site, Mozambique, Africa

footballer sweep (neatypus obliquus) diagonal yellow bands are edged in black and stand out against the silvery-blue body, wild, day, marine protected area, reef, in small schools diving off Rottnest Island, Western Australia, Indian Ocean. MORE INFO: other name stripey, eating green algae as they sweep over the reef.

Toxic blue green algae on Haweswater reservoir during a hot summer, Lake District, Cumbria, England, United Kingdom, Europe

Toxic blue green algae on Haweswater reservoir during a hot summer, Lake District, Cumbria, England, United Kingdom, Europe

A warning sign about Blue Green Algae in Cavendish Dock in Barrow in Furness, Cumbria, England, United Kingdom, Europe

Toxic blue green algae on Haweswater reservoir during a hot summer, Lake District, Cumbria, England, United Kingdom, Europe

Toxic blue green algae on Haweswater reservoir during a hot summer, Lake District, Cumbria, England, United Kingdom, Europe

Toxic blue green algae on Haweswater reservoir during a hot summer, Lake District, Cumbria, England, United Kingdom, Europe

Algae covered pebbles on the beach at night, Ponta do Sol, Madeira, Portugal

Cisterne of Habbaba, Yemen

A bass fisherman casts for fish in the Toxic Blue Green Algae in the Copco Reservoir in Northern California.

A bass fisherman casts for fish in the Toxic Blue Green Algae in the Copco Reservoir in Northern California.

A water quality researcher samples Toxic Blue Green Algae in the Copco Reservoir in Northern California.

Surgeonfish aggregate on the north coast of Komodo Island. Surgeonfishes are small-scaled, with a single dorsal fin and one or more distinctive, sharp spines that are located on either side of the tail base and can produce deep cuts. They are primarily algae eaters, Komodo Island, Indonesia

Sunlight streaming through a forest of giant kelp (Macrocystis pyrifera), off Santa Barbara Island, California, United States of America

Green sea turtles (Chelonia mydas), an endangered species, gathering at a cleaning station off Maui, Maui, Hawaii, United States of America