Study shows land-locked Atlantic salmon also use magnetic field to navigate

A new study shows that Atlantic salmon use the Earth's magnetic field as a navigational tool-much like their cousins, Pacific salmon-and do not lose that ability to multiply after having been transplanted into a land-locked lake.

The findings suggest that Atlantic salmon, which are widely used in aquaculture, may have greater potential to navigate and thus invade novel habitats if they escape their pens, researchers say.

Results of the study are published in this journal Proceedings of the National Academy of Sciences.

This is the first time in which one of the following is used for navigation. A landmark 2014 study by Oregon State University shows that Chinook salmon are using the ocean to target their oceanic foraging grounds.

Researchers at the Oregon Hatchery Research Center with several "arenas" surrounded by wooden coils wrapped in copper wire to mimic Earth's magnetic field, and tested 1,150 juvenile Atlantic salmon transported from Oregon's Hosmer Lake.

Atlantic salmon had first been brought to the land-locked lake of Maine some 60 years ago, and the researchers were curious to see if they had navigational abilities similar to ocean-going salmon, according to lead author Michelle Scanlan, faculty research assistant in OSU's College of Agricultural Sciences and lead author on the PNAS article.

"Pacific salmon oceanic range," Scanlan said. "If we put them in an extreme northern field, would they be 'race-correct' and align themselves in a southerly direction, and vice versa? And the answer was yes. field signal. "

Atlantic salmon is of particular concern because of an incident in August of 2017, when 200,000 to 300,000 Atlantic salmon escaped to aquaculture in Washington's Puget Sound. Eight months later, one of the fish was reportedly caught 40 miles up the Skagit River, raising concerns about the native salmon impact and the ecosystem.

Atlantic salmon farms.

The study also raises some interesting questions, said Nathan Putman, a senior scientist with LGL Ecological Research Associates in Bryan, Texas, who led the 2014 Pacific salmon navigation study as a post-doctoral scholar at OSU.

"Why did not the Hosmer Lake fish lose their ability to navigate?" Putman said. It is possible that they have some finer-scale navigation tools at their disposal to a lake. of spatial tasks that might be more useful than a little bit more of a question of maneuvering through the water column. "

A study by the same researchers published in February Biology Letters found that larval salmon uses the magnetic field when emerging from "redds" or nests and into the water column-suggesting salmon do not have any fine-scale magnetic tools that may be fully identified.

We have a broad scale, however, the use of the magnetic field explains, in part, how salmon can find the way to their river of origin.

"Said Amanda Pollock, a graduate student in the US Department of Fisheries and Wildlife and co-author on the study. "That gets them close to their olfactory senses and senses their kick in."

And that ability is retained over many generations of landlocked individuals.

Explore further:
Newly-hatched salmon use geomagnetic field to learn which way is up

More information:
Michelle M. Scanlan el al., "Magnetic map in nonanadromous Atlantic salmon," PNAS (2018). www.pnas.org/cgi/doi/10.1073/pnas.1807705115