Dolphin Deaths on the Rise in 2013 A number of things can cause dolphins to strand, including harmful algal blooms, infectious viruses, injuries due to ship strikes, pollutants and human-made runoff, NOAA said. Although the cause has not been determined, early tissue analysis showed that one suspect could be morbillivirus, an infectious pathogen, said Teri Rowles, national marine mammal stranding coordinator for NOAA Fisheries.