Northern bottlenose whales are deep-diving cetaceans of the North Atlantic. Strandings, sonar disturbance, and entanglement in fishing gear are primary welfare threats.
Northern bottlenose whales are highly social animals that may suffer acutely from both injury and social disruption. When military sonar exercises cause whales to surface rapidly, gas bubble formation in tissues causes severe pain analogous to decompression sickness in divers. Stranded animals often show evidence of internal haemorrhage and extreme distress. The deep-sea habitat of bottlenose whales means most welfare incidents go unobserved, and the full scale of sonar-related harm is likely underestimated.