in correlation with military exercises in Greece, the Bahamas, Madeira, and the Canary Islands. The livers of these animals had the most damage. In 2019, a review of evidence on the mass strandings of beaked whale linked to naval exercises where sonar was used was published. It concluded that the effects of mid-frequency active sonar are strongest on Cuvier's beaked whales but vary among individuals or populations, and the strength of their response may depend on whether the individuals had prior exposure to sonar. The report considered that the most plausible explanation of the symptoms of decompression sickness such as gas embolism found in stranded whales to be the whales' response to sonar. It noted that no more mass strandings had occurred in the Canary Islands once naval exercises where sonar was used were banned there, and recommended that the ban be extended to other areas where mass strandings continue to occur. Four species are classified by the IUCN as "lower risk, conservation dependent": Arnoux's and Baird's beaked whales, and the northern and southern bottlenose whales. The status of the remaining species is unknown, preventing classification. Captivity Beaked whales live very short lives in captivity when compared to other cetaceans such as common bottlenose dolphins and short-finned pilot whales, most surviving only a few days out of the ocean. The longest time period for a beaked whale living in captivity was 25 days. Alexander and Nicholas, two male beaked whales—their species unknown, though they were thought to be either Hubbs' beaked whale or Blainville's beaked whale—had become stranded in California on 24 August 1989. They were taken to Marine World California. Both of the whales would die of pneumonia; Nicholas died on 8 September and Alexander died 10 days later. A handful of other beaked whales have been briefly kept in captivity. A juvenile female Cuvier's beaked whale was found stranded on a kelp bed off of Santa Catalina Island on 23 February 1956. She was taken to Marineland of the Pacific, where she was named Martha Washington. On 16 June 1969, a Cuvier's beaked whale live stranded in St. Augustine. The whale, thought to be a male, was then transported to Marineland of Florida. It is unknown what happened to the whale, but it was still alive on 18 June 1969. References External links The Beaked Whale Resource Beaked whales - into the abyss - BBC News article Diving