Deep divers inshore drive
Northern bottlenose whales up Loch Sunart in August 2023, photographed and reported by Whale Tracker, PeterSelway
Inshore movement of deep diving whales in Scottish coastal waters documented by community sightings volunteers.
Data collected by HWDT’s Whale Track sightings community 2019-2023 shows a predictable occurrence of northern bottlenose whale sightings in Scottish inshore waters in late summer, early autumn. Northern bottlenose whales move on to the continental shelf from deeper oceanic waters, mainly between July and October. The same trend is shown in historical whaling records and strandings data. When in inshore waters they are typically reported in the deep areas of seabed for example around Skye.
Data gathered by the Whale Track community between 2019 - 2023, detailing the number of sightings of northern bottlenose whales reported
A pair of northern bottlenose whales were reported right up Loch Creran in 2020 by Whale Tracker, ruth-gonzalez.
Northern bottlenose whales are deep-water specialists found in the North Atlantic Ocean. The preferred prey of the northern bottlenose whale is squid, and they can dive to at least 1500 metres for up to two hours to catch their prey.
The northern bottlenose whale is a beaked whale (family Ziphiidae) that has a very distinctive bulbous melon (forehead) and a pronounced beak. Sound is important to northern bottlenose whales; they make a complex range of calls for navigation, foraging and communicating with one another.
Males possess two, slightly forward-pointing teeth at the front of the lower jaw, which are used by competing males to ‘joust’ each other. They also have ‘pectoral pockets’; indentations in the flanks to place the pectoral fins to increase streamlining during deep dives.
Community monitoring is incredibly valuable for elusive species like the deep divers such as northern bottlenose whales. Enabling researchers to detect trends and identify peaks in sightings which wouldn’t be possible through dedicated surveys alone.
Northern bottlenose whales are sensitive to underwater sound and are well documented to be impacted by military sonar. The fact that the presence of this vulnerable species in coastal waters coincides with a large-scale military training exercise, NATOs Joint Warrior, on a near annual basis is a serious conservation concern.
HWDT have long-standing concerns about the impact that Joint Warrior exercises (and the testing period prior to these exercises) have on many species of cetaceans. Cetaceans are reliant on using sound to navigate, find food and communicate, and are extremely sensitive to underwater noise pollution. Military sonar used during these operations produces an intense loud noise and scientific literature clearly links disturbance, at-sea injury and mass strandings of cetaceans to the use of military sonar.
Through Whale Track, community sightings are providing valuable information about the presence and behaviour of cetaceans, and through HWDT’s dedicated research expeditions volunteers are documenting the underwater soundscape in the region to better understand the threats and how to best protect cetaceans in Scottish waters. Every sighting is important.