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

Animals

Underwater view of developing sockeye salmon (Oncorhynchus nerka) eggs in Power Creek near Cordova and Prince William Sound; Alaska, United States of America

Animals

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

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

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

Animals

Underwater view of migrating pink salmon (Oncorhynchus gorbuscha) in Hartney Creek near Cordova, Alaska in the summer; 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

Underwater view of a female pink salmon (Oncorhynchus gorbuscha) probing with her anal fin in Hartney Creek near Cordova, Alaska in the summer; Alaska, United States of America

Underwater view of a pink salmon (Oncorhynchus gorbuscha) spawning pair with an aggressive sneaker male gaping in Hartney Creek near Cordova, Alaska in the summer; 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

Mature Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) male in nuptial (breeding) coloration 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 Alaskan stream during the summer; Alaska, United States of America

Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) male crosses over a female as part of courtship in an Alaskan stream during the summer; 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

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

Incidental tree branch bites can result from the aggressive behavior of male Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) competing to spawn in an Alaskan stream during the summer; Alaska, United States of America

Underwater view of King Salmon (Class Actinopterygii) in Moose Creek, a tributary of the Deshka River, South-central Alaska; Alaska, United States of America

A female Sockeye Salmon, also known as Red Salmon (Oncorhynchus nerka) attacking a female who is excavating a redd that is too close to hers in an Alaskan stream during the 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

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

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