Wildlife

New Explanations Sought for Dolphin Strandings

In waters from Florida to the Caribbean, dolphins are showing up stranded or entangled in fishing gear with an unusual problem: They can’t hear.

A study has found that more than half of stranded bottlenose dolphins and more than a third of stranded rough-toothed dolphins had severe hearing loss. The animals’ hearing impairment may have been a critical factor in their strandings. The causes of hearing loss in dolphins aren’t always clear, but aging, shipping noise and side effects from antibiotics could play roles.

Whether the hearing loss is causing the dolphin strandings — for instance, by steering the marine mammals in the wrong direction or preventing them from finding food — remains an open question.