Acoustic diversity of Arctic marine mammals of Fram Strait
Although the Fram Strait presumably provides an important habitat for several marine mammals, including several baleen whale, toothed whale and seal species, the migratory behavior and both the spatial and temporal distribution of marine mammals in Arctic waters remain poorly under-stood. While some of the marine mammals inhabit Fram Strait year-round, others are only pre-sent for some months when migrating towards high-latitude waters during summer. This study presents baseline data of the spatial and temporal distribution of marine mammals in Arctic Fram Strait. As marine mammals are known to produce various vocalizations in different behavioral contexts, acoustic presence of marine mammals in Fram Strait was studied. Between 01 July and 30 November 2012 passive acoustic data were collected at 78° 49, 76’ N to 0° 25, 77’ E. During the recording period blue whales (Balaenoptera musculus), fin whales (Balaenoptera physalus), bowhead whales (Balaena mysticetus), narwhals (Monodon monoceros), sperm whales (Physeter macrocephalus) and harp seals (Pagophilus groenlandicus) were acoustically present. Further-more, the vocalizations of detected marine species are presented in this study. Variations of pre-viously classified call types of bowhead whales, harp seals and sperm whales were recorded. Additionally, a presumably unknown call type of narwhals was found. The results show temporal acoustic presence of bowhead whales and narwhals in October and November and acoustic ab-sence from July - September. Their presence in fall may indicate that they either overwinter or remain longer in central Fram Strait. Furthermore, fin whale calls were heard from July until October and were absent in November. Blue whales and harp seals were acoustically present throughout the recording period. Sperm whales were acoustically present in July and September and acoustically absent in June, August, October and November. Therefore, it can be assumed that Fram Strait may serve as a feeding ground for fin whales, blue whales, harp seals and sperm whales. Since many of the marine mammals are listed as critically endangered, it is important to know where they are distributed. The results of this study will help to better understand the dis-tribution patterns of marine mammals in Arctic Fram Strait.