Paul Williams / Ochre starfish (Pisaster ochraceus), Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus) in rock pool, Vancouver Island, British Columbia, Canada, July.

Paul Williams / Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus), Vancouver Island, British Columbia, Canada, June.

Paul Williams / Goose barnacles (Pollicipes polymerus) and California mussel (Mytilus californianus), Vancouver Island, British Columbia, Canada, June.

Paul Williams / Ochre starfish (Pisaster ochraceus) California mussel (Mytilus californianus) and Giant green anenome (Anthopleura xanthogrammica) in rock pool, Vancouver Island, British Columbia, Canada. July.

Werner Bollmann / Blue mussels (Mytilus edulis) Vestvagoy, Norway, March 2012.

Sandra Bartocha / Blue Mussels (Mytilus edulis) Bohuslan Archipelago, Sweden, July 2015.

Solvin Zankl / Diver fisherman collecting Chilean blue mussel (Mytilus chilensis) Comau Fjord, Patagonia, Chile, Pacific Ocean, January

Solvin Zankl / Diver fisherman collecting Chilean blue mussel (Mytilus chilensis) Comau Fjord, Patagonia, Chile, Pacific Ocean, January

Solvin Zankl / Local fishermen and boats setting out to collect Chilean blue mussels (Mytilus chilensis) Comau Fjord, Patagonia, Chile, January 2013

Solvin Zankl / Yellow encrusting anemone (Parazoanthus elongatus) and Chilean blue mussel (Mytilus chilensis) Comau Fjord, Patagonia, Chile Pacific Ocean

Solvin Zankl / Diving fisherman collecting Chilean blue mussel (Mytilus chilensis) Comau Fjord, Patagonia, Chile, Atlantic Ocean

SCOTLAND: The Big Picture / Horse mussel (Modiolus modiolus) bed with Brittlestars (Ophiothrix fragilis) and Edible crab (Cancer pagurus), Shetland, Scotland, UK, September.