sonars and strandings: Are beaked Whales the Aquatic Acoustic Canary?

Introduction On the morning of 15 March, 2000, phones began ringing in Washington, Virginia, and Massachusetts. Emails flew between the USA and the Bahamas. The event behind these communications was a mass stranding of beaked whales (Ziphiidae) in the northern Bahamas extending from Grand Bahama to the tip of Abaco (Evans and England, 2001). Over two days, 17 whales were reported on shore, of which nearly half succumbed to the stress and trauma of stranding. Four years earlier, in 1996, 12 overtly healthy Cuvier’s beaked whales (Ziphius cavirostris) beached and died near ship based trials of mid and low frequency sonars in Kyparissiakos Gulf, off the Peloponnesian coast of Greece. It soon became evident that the Bahamian stranding, like the one in Greece, coincided with naval sonar exercises in nearby waters immediately prior to the beachings of these normally elusive, deep diving, deep water whales (Figure 1). Since then, there have been multiple similar events: Madeira (2000), Canary Islands (2002, 2004), Hawai’i (2004), Madagascar (2008), and again Greece (Corfu 2011, Crete 2014), some involving military vessels and sonars; others, industrial and research vessel sonars, fueling demands that scientists solve the question of the relationship between marine mammal strandings and intense sound sources (Frantzis, 1998; Freitas, 2004; Ketten et al., 2004; D’Amico et al., 2009; Fernandez et al., 2012). Darlene R. Ketten