Nick Hawkins / Chum salmon (Oncorhynchus keta) migrate up a small river near Bella Bella, British Columbia, Canada. September

John Waters / Small group of Rainbow trout (Oncorhynchus mykiss) swimming in the River Kennet, Berkshire, England, UK, March.

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) mother watching cub catching salmon, Katmai National Park, Alaska, USA, August

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cubs with salmon, Katmai National Park, Alaska, August. Small reproduction only.

Loic Poidevin / Grizzly bear (Ursus arctos horribilis) cubs with salmon, Katmai National Park, Alaska, August. Small reproduction only.

Charlie Summers / Black Bear (Ursus americanus) with Pink Salmon (Oncorhynchus gorbuscha) catch, Anan Creek, Alaska, July.

Michel Roggo / Brown bear (Ursus arctos beringianus) fishing for Sockeye salmon in the Ozernaya River, Kamtchatka, Russia, August

Chris & Monique Fallows / Pink Salmon (Oncorhynchus gorbuscha) migrating in small shallow river, Prince William Sound, Alaska, USA.

Alex Mustard,Alex Mustard / Rainbow trout (Oncorhynchus mykiss) under trees, Capernwray Lake, Lake District, England, UK.

Alex Mustard,Alex Mustard / A female (in front) and male Sockeye salmon (Oncorhynchus nerka) over eggs in their spawning river. Adams River, British Columbia, Canada, October.

Alex Mustard / A split level photo of group of Sockeye salmon (Oncorhynchus nerka) fighting their way upstream as they migrate back to the river of their birth to spawn, trees showing autumnal colours. Adams River,...

Michel Roggo / Sockeye / Red Salmon (Oncorhynchus nerka) on spawning migration; males surrounding a female. Adams River, British Columbia, Canada, October.