Since healthy whales are equipped with several abilities to detect their surrounding thoroughly, it is often difficult to explain why healthy individuals find themselves stranded in shallow water. New research presented by Jesse Granger at the Society for Integrative and Comparative Biology meeting in Austin, Texas, has shed light on a possible explanation.
Granger and her colleagues reviewed gray whale stranding data from the U.S. West Coast between 1985 and 2018. Surprisingly, they found that gray whales were nearly five times more likely to strand when there was a high prevalence of sunspots. Sunspots are darker regions on the sun’s surface that are caused by concentrations of magnetic field flux. Most solar storms originate in such magnetically active regions around visible sunspot groupings, resulting in a high level of radio wave emission. While most of this electromagnetic radiation does not make it to the earth’s surface, Granger explains that “there’s a huge chunk in the radio frequency wave range that does make it all the way to the Earth. And it has been shown in several species that radio frequency noise can disrupt a magnetic orientation ability”.
Though it is still unsure whether whales use magnetoreception, migratory species such as gray whales are likely candidates to rely on magnetic cues for their navigation. A change in the magnetic field due to an increase in radio frequency might then lead the whale to read the map of the area incorrectly. As a consequence, they deter them from their route and end up stranded in unsuitable territories.
Until now, this study – as well as similar ones on the topic – solely shows that there is a correlation between the number of stranded whales and high density of sunspots. Whether whales are actually influenced by a change in radio frequency and what the underlying mechanism might be is thus still unclear. Further research will be necessary to determine if whales do have a magnetic compass or if a different, yet undiscovered phenomenon might cause this effect.
The coverage of the research presentation can be found at https://www.livescience.com/solar-storms-and-gray-whale-strandings.html
Comentarios