Department of Energy Argonne National Laboratory Office of Science NEWTON's Homepage NEWTON's Homepage
NEWTON, Ask A Scientist!
NEWTON Home Page NEWTON Teachers Visit Our Archives Ask A Question How To Ask A Question Question of the Week Our Expert Scientists Volunteer at NEWTON! Frequently Asked Questions Referencing NEWTON About NEWTON About Ask A Scientist Education At Argonne Returning Spawning Salmon
Name: Sana
Status: student
Age: 16
Location: N/A
Country: N/A
Date: Monday, June 17, 2002


Question:
How do Salmon know how and when to return to the initial habitat, after migrating miles away.


Replies:
Sana,

The current theory is that each stream, river, etc. has a "signature scent". This scent is characterized by the rock and mineral composition that the stream, etc. runs through picking up the chemical components of the rocks and minerals. If this idea does test out and there is one study that indicates it may, all the salmon has to do is find itself nearby in the ocean and it can locate the stream by the streams unique chemical composition or "scent".

We are finding that many animals including fish have the ability to find general direction because they have a built in compass molecules in special cells located in the brain. This compass has been identified in migratory birds. I'm not sure if salmon has been verified to has this too, but I suspect they do.

Most salmon live a set number of years, so when they become sexually mature, they return to breed in their home stream and die of exhaustion from the upstream swim to the streams head waters (or close) where they hatched.

If salmon have this compass and they can detect the signature scent of their home stream, this would explain their behavior. I have to point out that this has not been shown conclusively.

Steve Sample


Click here to return to the Zoology Archives

NEWTON is an electronic community for Science, Math, and Computer Science K-12 Educators, sponsored and operated by Argonne National Laboratory's Educational Programs, Andrew Skipor, Ph.D., Head of Educational Programs.

For assistance with NEWTON contact a System Operator (help@newton.dep.anl.gov), or at Argonne's Educational Programs

NEWTON AND ASK A SCIENTIST
Educational Programs
Building 360
9700 S. Cass Ave.
Argonne, Illinois
60439-4845, USA
Update: June 2012
Weclome To Newton

Argonne National Laboratory