Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) in the act of spawning in an Alaska stream during the autumn; Alaska, United States of America

A courting male Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka), crosses over a female in an Alaskan stream during the summer; Alaska, United States of America

Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) in the act of spawning in an Alaska stream during the autumn; Alaska, United States of America

Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) in the act of spawning in Sheridan River (Copper River Delta) tributary stream during autumn; Alaska, United States of America

Female Coho Salmon, also known as Silver salmon (Oncorhynchus kisutch) commencing to spawn about to be joined by a jack in an Alaskan stream during autumn; Alaska, United States of America

Male Coho Salmon, also known as Silver salmon (Oncorhynchus kisutch) with battle scars from fighting with other males over spawning rights in an Alaskan stream during autumn; Alaska, United States of America

To encouage his mate to spawn, a male Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) gapes in an Alaskan stream during the autumn; Alaska, United States of America

A male Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) comes alongside and quivers a female as part of courtship in an Alaskan stream during the autumn; Alaska, United States of America

Alpha male Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) maintains his position just ahead of a rival effectively blocking it's view of the female on his other side in an Alaskan stream during autumn; Alaska, United States of America

Dolly Varden Charr (southern form; Salvelinus malma lordi) male within the flooded ruins of an historical Alaska Territory salmon hatchery during the autumn; Alaska, United States of America

Brown bear (Ursus arctos) carrying sockeye salmon (Oncorhynchus nerka) in rapids of Brooks River, Katmai National Park and Preserve, Southwest Alaska

Pink Salmon (Oncorhynchus gorbuscha) probes her redd in an Alaskan intertidal stream during summer.

Close up of Rainbow Trout (Oncorhynchus mykiss); Alaska, United States of America