Whale Strandings: Five Questions Answered

HOBART, Australia: The death of around 200 pilot whales on a Tasmanian beach has renewed questions about what caused these mass strandings and whether they can be prevented.

Karen Stockin, a whale stranding expert at Massey University of New Zealand, answers five key questions:

Q: What causes mass strandings?

A: Scientists are still trying to figure this out. They know that there are multiple types of stranding events, with multiple explanations that may overlap. The causes can be natural, based on bathymetry – the shape of the ocean floor – or they can be species-specific.

Pilot whales and several species of smaller dolphins are known to strand regularly, especially in the Southern Hemisphere, according to Stockin. In some cases, a sick whale has made its way to shore and a whole pod has unknowingly followed them.

Q: Does this happen in certain regions?

A: There are a few global hotspots. In the Southern Hemisphere, Tasmania and New Zealand’s Golden Bay have seen several cases, and in the Northern Hemisphere, US Cape Cod Bay, Massachusetts, is another hotspot.

In these areas, there are similarities between beach topography and environmental conditions. For example, Cape Cod and Golden Bay share a narrow, prominent coastal feature and shallow waters with large tidal variations. Some people call these areas “whale traps” because of how quickly the tide can retreat.