Three long‐finned pilot whales Globicephala melas were equipped with satellite‐linked time‐depth recorders on the Faroe Islands on 15 July 2000. The purpose was to study the diving behaviour and habitat use of free‐ranging pilot whales in the northeast Atlantic. Summarised data on the diving behaviour of the whales were collected for up to 129 6‐hour periods. The maximum depth of dives was 828 m and the mean number of dives below 12 m was 12.2/hour (SD = 8.2). On average, the whales spent 60% of their time above 7 m depth. All three whales had significantly longer surface times when they were outside the continental shelf than when they were on the shelf. The mean vertical speeds ranged from 0.9 m/second for dives to 150 m to 2.3 m/second for dives to 600 m. No dives below 12 m lasted longer than 18 minutes, and more than 60% of dives lasted less than three minutes. The mean number of dives that lasted less than one minute was significantly higher in offshore areas than on the continental slope for all three whales. Compared to other odontocetes of similar size, long‐finned pilot whales apparendy either have a lower dive capacity or utilise a niche in the water column that requires less diving activity.

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Marine fisheries are often allocated to stocks that reflect pragmatic considerations and may not represent the species’ spatial population structure, increasing the risk of mismanagement and unsustainable harvesting. Here we compile mark–recapture data collected across the North Atlantic to gain insight into the spatial population structure of Greenland halibut (Reinhardtius hippoglossoides), an issue that has been unresolved for decades. The dataset contains 168130 fish tagged from 1952 to 2021, with 5466 (3.3%) recaptured individuals. Our results indicate that fish tagged at <50 cm body length migrate at higher rates, suggesting that mark–recapture studies on adult individuals underestimate population-level migration rates. We find evidence for migrations across management units in the North Atlantic indicating two regional offshore populations: one in the Northeast Atlantic, where the West Nordic and Northeast Arctic stocks, currently managed separately, likely belong to a single population that spans from the Kara Sea to Southeast Greenland; and one in the Northwest Atlantic where migration was observed between the Newfoundland and Labrador stock and the Northwest Arctic stock in Davis Strait and Baffin Bay. Our findings indicate complex population structure with implications for international and domestic fisheries management of this long-lived species.

Short-term movements of long-fin ned pilot whales Globicephala melas around the Faroe Islands. -Wildl. Biol. 9: 47-58.On 15 July 2000, a pod of about 80 long-finned pilot whales Globic ephala melas was driven to the coast at Sandavágur, the Faroe Islands (62.055°N, 7.157°W) for the purpose of tagging selected whales with satellite-linked radio transmitters. A transmitter was attached to the anterior flank of the dorsal fin of four beached whales. After the tagging, all four whales were reunited with their pod and the entire pod was driven to sea. The positions of three of the four whales were tracked (one for a period of 47 days) and the results show that the whales separated after a few days and eventually went in different directions. After 10 days, two of the whales were observed together in a pod, and after 19 days two of the whales were located at positions determined to be within 2.3 km of each other. The whales showed a strong affinity for the deep water off the continental shelf. The sex and relatedness of the four, tagged whales were determined from skin biop sies. The tagged whales comprised one adult female with one juvenile in puberty, possibly her male offspring, and two adult males, one of which could be the offspring or the sibling of the female. The swimming speed of the whales was estimated at 0.2-14.5 km/hour, and they travelled average distances of 70-111 km/24 hours with a maximum of 200 km in 24 hours. Considering the mobility of the whales, it seems likely that the catches that occur at the Faroe Islands are recruited from a larger area in the North Atlantic than previously presumed. This suggests that the whales are taken from a larger population than that estimated from coastal areas around the Faroe Islands, hence increasing the probability that the harvest is sustainable.

<p>Maturation, reproduction and early life history of <em>Lophius piscatorius </em>was investigated in Faroese waters. Length at first maturity (L50) was 58 cm for males and 84 cm for females, corresponding to an age of about four years for males and seven years for females. The proportions of females and males were similar in fish less than 55 cm long, and were skewed towards more males in medium sized fish (55–75  cm).  Females  were  predominant  in the larger fish (&gt; 85 cm). Observations of spawning males and females, egg ribbons and pelagic anglerfish larvae, suggest that the main spawning season is from February to April and the spawning area seems to be southwest of the Faroe Plateau and in the Faroe Bank area. The Faroe Plateau probably serves as a nursery ground for juvenile anglerfish. Morphological transformation from larvae to juveniles occurred when the fish were about 7–9 cm long and they settled to the bottom when they were about 11 cm long. Thus, all life stages, as well as nursery areas, spawning areas and feeding areas of anglerfish are found in Faroese waters, indicating a separate stock in the area.</p>