Habitat use of the northern bottlenose whale (Hyperoodon ampullatus) near Jan Mayen, North Atlantic

Habitat use of the northern bottlenose whale Hyperoodon ampullatus in the Northeast Atlantic is poorly understood. This study aimed to identify locally utilised habitat features and create predictions of northern bottlenose whale habitat use over a wider area around the island of Jan Mayen, Norway. Bottlenose whales were sighted regularly near Jan Mayen in June 2014–2016 at higher rates than over a wider study region reported in other studies, indicating that the Jan Mayen habitat may be a hotspot of bottlenose whale presence in early boreal summer. Habitat models were created by fitting generalised additive models of selected environmental variables to sighting occurrence and additional whale sightings given a first encounter (total number of sightings – 1) recorded in June 2014–2016. Higher occurrence was estimated at steeper topography and April-average chlorophyll concentration below 0.4 mg m–3. Additional whale sightings given a first encounter were predicted to be higher at water ...,
Visual sighting data of bottlenose whales were collected in June in 2014, 2015, and 2016, with search effort concentrating along the submarine canyon from north to southeast of Jan Mayen Island. Visual surveys were conducted by 2 dedicated observers from the deck whenever weather conditions permitted. Both observers made visual scans from bow to stern, with one observer searching across the starboard and the other across the port of the boat, together covering 360° around the vessel. Binoculars were used to confirm whale species and location once an animal was spotted.

When a sighting was made, the time, whale location (latitude and longitude), estimated sighting distance, bearing, group size, animal heading, and level and duration of seeking (behavioural indication of attractive movement towards the research vessel, as suggested by Whitehead & Hooker 2012) were recorded. Vessel GPS location and speed were automatically logged every 5 s in 2014 and 2015, and every 1 s in 2016.

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