This Pink or Humpback Salmon (Oncorhynchus gorbuscha) takes a deep breath so as to increase its oxygen intake as it journeys up his natal stream during the spawning run. These "Humpies" return from the sea every 3-4 years, initially guided by the earth's lines of magnetic force, then smell, to find their waters of birth. This information gathered from research and discussions with marine biologists. Hopefully I have not lead you astray.
This image was taken in Walker Cove Creek in Misty Fjord National Monument of Southeast Alaska. The camera data in the EXIF file is not accurate as selections for my Nikon AW1 with 11.5-27mm f3.5 lens are not available.
One thing I would like to mention is the dangers imposed by bears. Both Brown and Black Bears are in the area and are attracted to spawning streams. I had a "lookout" while I photographed who was alert for danger. No doubt about it, we were trespassers as the bears owned any part of this stream they wanted!