Dolphin strandings a crucial resource for scientists

Jan 28, 2013

Two common dolphins rescued and released in Wellfleet, MA, in 2012.
Credit IFAW

There's nothing pretty or happy about marine mammal strandings, but they can be useful. Katie Moore should know; she's manager of marine mammal rescue and response for the International Fund for Animal Welfare, and she's responded to hundreds of strandings.

Cape Cod is one of three major hotspots for marine mammal strandings worldwide. (The others are in Australia and New Zealand.) Each winter, dozens - sometimes hundreds - of dolphins and small whales wash up on the shores of Cape Cod Bay, particularly in Wellfleet. 2012 was a record-breaking year, with 217 common dolphins stranding in four-month period.

While nobody knows exactly why, it's thought that the Cape's shape is a major factor. The flexed arm stretching out into the Atlantic encircles animals, and the sloping beaches and fine sediments that line Cape Cod Bay can make it difficult for marine mammals to navigate.

Mass strandings are emotionally charged events for both responders and the public. The prospect of otherwise healthy dolphins (face it, everybody loves dolphins) languishing on Wellfleet's mudflats can be distressing. And responders face the difficult task of determining whether an animal is, in fact, healthy enough to be released or whether euthanasia is the most humane course of action. In that event, what follows is the somewhat gruesome task of a necropsy, or animal autopsy.

But there is a silver lining. It's hard for scientists to study open-ocean animals, particularly those that are protected as marine mammals are. Strandings offer unique access to both living and dead animals, and have become recognized as a major resource for marine mammal researchers. Studies of hearing, physiology, pollutants, and diseases have all benefited from strandings.

The improved understanding of dolphin physiology that has come from over a decade of stranding science has changed how responders view stranded animals. They now know that most animals in a mass stranding event are healthy, not ill or fatally impaired. As a result, the rate of successful releases has increases dramatically. That, in turn, changes what science is done. But strandings - and stranding science - are likely to be around as long as Cape Cod is.