You would probably have heard of salmon as ‘sentimental’ because they eventually swim to their natal location to reproduce and give birth to their young. This romanticised salmon, however in reality, salmon swims home for a few reasons. How do they trace their way home? When do they know when to travel?
Salmon is the common for several species of fish. The scientific name of the family is Salmonidae. The family includes pink, chinhook, coho and many more. They belong to a special type of family as they practise migration before spawning.
As mentioned in the book ‘The Behavior and Ecology of Pacific Salmon and Trout’ , author Thomas P. Quinn said that salmon diverge at some point when they are about to travel back to their home river. Even when they are mixed with other species, they are able to sense the environmental changes taking place ( temperature of the water and food available) around them and every fish react differently. Not only that, they do converge later before entering the natal river.
One amazing thing is that they must control their travel rate so that no excess energy is loss. A salmon of 60 cm length is reported to be able to swim 2.16 km/h if it swims in a straight line. The distance traveled would not seem short when taking into consideration that salmon is constantly swimming upwards. It is likely to face danger from predators as it uses much energy in swimming upstream. Not only that, salmon’s survival rate is also facing danger from environmental desturction arising from human construction of dams.
No matter how much danger or effort it takes, salmon still has the genetic factor which entice it to go home.
‘The Behavior and Ecology of Pacific Salmon and Trout’ By Thomas P. Quinn. Published by University of Washington Press, 2005. Google book. ( accessed on 8 April)
‘ Do dams make a difference? Similar Survival Rates For Pacific Salmon in Fraser And Columbia Rivers. By ScienceDaily ( Oct 30, 2008) URL: http://www.sciencedaily.com/releases/2008/10/081028074430.htm ( accessed on 8 April)