Jan Hamrsky,Jan Hamrsky / Trumpet animalcules (Stentor polymorphus) with algal symbionts (Chlorella), Europe, controlled conditions

SINCLAIR STAMMERS / Phase contrast photomicrograph of Blue green alga / Cyanobacteria (Spirulina platensis) each algal filament or Trichome is 5 microns in diameter.

Sue Daly / Hawksbill turtle (Eretmochelys imbricata) with algal growth on carapace, Cebu, Philippines, March, Endangered species

Nick Garbutt / Algal mats in front of Punch Bowl thermal pool. Near Daisy Geyser Basin, Yellowstone National Park, USA.

Heather Angel / Feeding trails made by snail using radula strip with rows of tiny teeth on geen algal film on glass pane. Tropical butterfly house, Kunming, Yunnan Province, China.

Alex Mustard / Foam on the surface of the ocean, probably caused by a algal bloom (Phaeocystis globosa) Lands End, Cornwall, England, United Kindom. British Isles. North East Atlantic Ocean

John Cancalosi / Snapping turtle (Chelydra serpentina) in blue-green algal bloom (Woronichinia naegeliana). Microcystin produced is toxic to wildlife and humans. Maryland, USA. October 2018.

John Cancalosi / Snapping turtle (Chelydra serpentina) in blue-green algal bloom (Woronichinia naegeliana). Microcystin produced is toxic to wildlife and humans. Maryland, USA. October 2018.

John Cancalosi / Snapping turtle (Chelydra serpentina) in blue-green algal bloom (Woronichinia naegeliana). Microcystin produced is toxic to wildlife and humans. Maryland, USA. October 2018.

John Cancalosi / Snapping turtle (Chelydra serpentina) amongst leaves in blue-green algal bloom (Woronichinia naegeliana). Microcystin produced is toxic to wildlife and humans. Maryland, USA. October 2018.

Ashley Cooper / Blue Green algae on the shores of Lake Windermere, Ambleside, Lake District, UK. Blue Green algae is toxic and is becoming far more frequent as temperatures rise due to climate change. June 2014

Alan Williams / Algal bloom or scum forming on small lake near Burton, Cheshire, UK, July.