batch_auto_20260713 202607131256465730 BOEM ESP geoESPIS ESPIS@boem.gov Bureau of Ocean Energy Management Inter-disciplinary Study of the Possible Link Between Space Weather, Geomagnetic Storms and Cetacean Mass Strandings Heliophysics Science Division NASA Goddard Space Flight Center Cetacean mass strandings are one of the long-standing mysteries in marine biology and many explanations have been proposed for the often-fatal animal behavior. Geomagnetic activity is one of the proposed explanations and in this study, we investigate whether there is statistical evidence for a possible connection. Mass stranding records from Cape Cod, U.S., the United Kingdom and New Zealand, together with global geomagnetic indices and local geomagnetic observations, are utilized in this investigation. Both event-based and rigorous statistical analyses are applied to test the possible causal association between mass strandings and geomagnetic activity. While seasonal statistical association is found between cetacean mass strandings and geomagnetic field variations, the connection is likely spurious and rises due to the seasonal dependence present in both types of data. No statistical association is found in 30-day or shorter time scales that are believed to be relevant for possible animal response to changes in geomagnetic conditions. If geomagnetic activity plays any role in mass strandings, the connection has to be very subtle and likely coupled with a complex combination of multiple environmental factors. The importance of various environmental factors likely depends on the stranding locations and individual cetacean species and consequently, the reported findings apply directly only to the Cape Cod, United Kingdom and New Zealand stranding cases studied. 135000 U.S. Department of the Interior, Bureau of Ocean Energy Management, Environmental Studies Program https://doi.org/10.13039/100012475 M16PG00026 10.67297/9A1DB9 https://boem.gov/awardpages/100153