Narwhals, by contrast, did not exhibit a similar decline. These patterns are consistent with historical records showing that commercial whalers primarily targeted bowhead whales.

There are over 90 whale species. Some of the most famous whale species are humpback whales, sperm whales, blue whales and narwhals. Despite their name, killer whales — or orcas — are not whales.

Narwhals have fascinated and confounded humans for centuries. Now an exhibition at Salem’s Peabody Essex Museum is diving into the mystery, history and science of these elusive tusked ...