The causes of mortality of stranded animals are multiple. A distinction is made between those of natural and man-made origin.
The stranded dolphins were old, very young or pregnant females.
Death is caused by a virus, bacteria or parasites.
The animal was attacked by a predator.
Inter or intra specific competition
The animals fought and their fight resulted in death.
Anthropogenic (man-made) causes
The intensification of maritime traffic is causing deadly collisions with large marine mammals.
Oil spills, micro-plastics, chronic chemicals, noise pollution, the degraded marine environment affects their survival.