Solar Driven Geomagnetic Anomalies and Sperm Whale (Physeter macrocephalus) Strandings Around the North Sea: An Analysis of Long Term Datasets

To stimulate the discussion about possible reasons for whale strandings, we suggest solar driven geomagnetic variations as one further explanation for this phenomenon. Following this hypothesis that whales may strand due to geomagnetic disturbances we compared annual means of stranding event numbers of sperm whales (Physeter macrocephalus) along the North Sea coasts with yearly averaged numbers of geomagnetic anomaly intensities (aaindices). Based on a Generalised Additive Model technique, our new approach suggests that over the last 400 years 20% of the stranding events can be correlated with aa-index variabilities. Furthermore, the increased stranding numbers of the last decades could be explained by the exceptional intensive disturbances of the earth’s magnetic field in the same period.