Animals

Underwater view of a sockeye salmon (Oncorhynchus nerka) spawning pair and a challenger male in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of a sockeye salmon (Oncorhynchus nerka) spawning pair and a challenger male in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of migrating pink salmon (Oncorhynchus gorbuscha) in Hartney Creek, with a Dolly Varden trout (Salvelinus malma) lurking near the bottom, near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of competing male sockeye salmon (Oncorhynchus nerka) in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of a competing sockeye salmon (Oncorhynchus nerka) in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of a male sockeye salmon (Oncorhynchus nerka) in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of male sockeye salmon (Oncorhynchus nerka) aggression in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of a female sockeye salmon (Oncorhynchus nerka) in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of maturing coho salmon (Oncorhynchus kisutch) holding in a pool in Hartney Creek near Cordova, Alaska in autumn; Cordova, Alaska, United States of America

Underwater view of caddisfly larvea consuming a sockeye salmon carcass in Power Creek near Cordova, Alaska in the summer; Alaska, United States of America

Pink and Chum salmon (Oncorhynchus gorbuscha and O. keta) summer spawning migration in a tributary of Prince William Sound, Alaska.

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) spawning pair in an Alaskan stream during the summer; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) spawning pair in an Alaskan stream during the summer; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) spawning pair in an Alaska stream during the summer, South-central Alaska; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) spawning in an Alaskan stream during the summer. The small male is a jack; Alaska, United States of America

Chinook Salmon, also known as King Salmon (Oncorhynchus tshawytscha) schooled in a holding pattern prior to spawning in a tributary of the Deshka River in summer; Alaska, United States of America

Anticipating spawning, male Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) approach a female probing her redd in an Alaskan stream during the summer; Alaska, United States of America

Mature male Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) in an Alaskan stream during the summer, South-central Alaska; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) probes her redd while a male guards in an Alaskan stream during the summer; Alaska, United States of America

Chinook Salmon, also known as King Salmon (Oncorhynchus tshawytscha) schooled in a holding pattern prior to spawning in a tributary of the Deshka River, South-central Alaska; Alaska, United States of America

Coho Salmon, also known as Silver Salmon (Oncorhynchus kisutch) crosses over the tail end of a female as part of courtship in an Alaskan stream during the summer; Alaska, United States of America

This female Sockeye Salmon (Oncorhynchus nerka) is creating a superimposition by excavating on an existing redd, South-central Alaska; Alaska, United States of America

While her alpha male guards, a female Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) excavates her redd in an Alaskan stream near Cordova, South-central Alaska; Alaska, United States of America

Underwater view of a pink salmon (Oncorhynchus gorbuscha) spawning pair in Hartney Creek near Cordova, Alaska in the summer; Alaska, United States of America