Re-hashing a 25 year old theory on how Salmon might find their way back to their Scottish birthplace

The Scotsman, Tall and Handsome Built ^ | December 2, 2008 | Ben Bailey

[SunkenCiv]

Every year, 20 million of them leave Scottish rivers and travel thousands of miles to Norway and Greenland to feed. Remarkably, they then return to Scotland, often to within 100 metres of where they were hatched, in a process that can take more than two years.

How salmon complete such voyages across sea and ocean without getting lost has baffled scientists for generations. But a new theory proposes that the fish use the earth's magnetic field to locate their origins in Scottish rivers.

Scientists believe that, in a process called "natal honing", salmon imprint the magnetic signature of their home once reaching adulthood...

The Earth's magnetic field varies across the globe – each oceanic region has a different magnetic signature. Researchers believe that by remembering the unique "magnetic address" of their birthplace, fish may be able to distinguish that location from all others.

Salmon and sea turtles often bypass suitable breeding grounds on their vast journeys in favour of the places they were born. Scientists believe the fish do this due to previous breeding success at a particular site...

Scientists agree the Earth's magnetic field changes over time and probably helps animals arrive only in the general area of their birthplace. Then, once an animal is close to their target, other senses, such as vision or smell, may be used. Salmon are known to use their sense of smell to locate spawning grounds once they are close.

[driftless2]

Some river around Banchory. Where one of my wife’s sisters lives.

[Pontiac]

certain Alaskan salmon adapted some 2000 y ears ago, when a volcano erupted and completely blocked their access to the rivers and streams where they spawned.

Don’t tell the environmentalist or the EPA. They would have a meltdown.

If that is true we could start building Hydroelectric Dams again.

[colorado tanker]

Maybe these guys can give us the answer:

[Mears]

I would strongly suggest the movie “Salmon Fishing in The Yemen”.

Very funny !