Vaxandi hávaði í hafinu: er tilvist hinnar leyndardómsfullu andarnefju (Hyperoodon ampullatus) ógnað? - verkefni lokið

Fréttatilkynning verkefnisstjóra

11.7.2024

Almennt er lítið vitað um lifnaðarhætti þessarar djúpkafandi hvalategundar. Mikil þörf er á aukinni þekkingu á atferli og vistfræði hennar, þannig að unnt sé að taka vel ígrundaðar ákvarðanir um verndun tegundarinnar og meta áhættu af völdum hljóðmengunar fyrir hvalina. Í rannsóknaverkefninu var notast við djúpsjávarhljóðnema og gervihnattasenda, auk annarra rannsóknaaðferða, til að kanna ferðir og atferli andarnefju. Niðurstöður benda til þess að frjósama svæðið á mörkum Íslandshafs og Noregshafs sé helsta fæðuöflunarsvæði tegundarinnar, jafnvel þótt þekkt sé að hvalirnir stundi ennfremur djúpar fæðuöflunarkafanir þegar þeir leita suður á bóginn. Slík djúpköfun reynist að meðaltali ná niður á eins kílómetra dýpi og standa yfir í um 49 mínútur. Rannsóknir á magainnihaldi strandaðra einstaklinga leiddi í ljós að fæða þeirra samanstóð aðallega af smokkfiski, einkum af tegundinni dílasmokki (Gonatus fabricii). Andarnefja sást stöku sinnum inni í íslenskum fjörðum og virtist nýta firðina sem skjól, en ekki fyrir fæðuöflun. Hluti stofnsins sem lifir í Norðurhöfum virðist ferðast suður Atlantshafið í byrjun sumars. Hvalirnir ná því að fara allt suður til Azoreyja og til baka á innan við tveimur mánuðum. Ástæða þessa óvenjulega fars gæti verið þörf andarnefjunnar fyrir að fara í húðlos eða húðfelli og losa sig þannig við áföst sníkjudýr.

English:
Noise disturbance is considered a threat of great concern for northern bottlenose whales because of the species’ dependence on sound for foraging, navigation and communication. Most of the global population is thought to reside in the deep offshore waters to the north and east of Iceland, but individual groups make occasional forays into the fjords, increasing their risk of stranding. Very little is known about this deep-diving whale in general, so basic behavioural and ecological knowledge is required to make informed conservation decisions and to assess the risk of noise disturbance. This project used deep-sea acoustic recorders, satellite tags and other observation methods to learn about the movements and behaviour of northern bottlenose whales. Results suggested that the frontal zone between the Iceland Sea and Norwegian Sea is indeed a prime foraging habitat for the species, although tagged whales continued to make deep foraging dives further south. Such deep dives were on average 1.0 km deep and 49 min long. Analyses of the stomach contents of stranded individuals confirmed that their diet mainly consisted of squid, especially Gonatus fabricii. Northern bottlenose whales were occasionally observed in the Icelandic fjords and appeared to use these waters as a refuge and not for foraging. A proportion of the Nordic Seas population seems to migrate south into the Atlantic at the start of summer, with whales making round-trip migrations to the warm waters near the oceanic archipelago the Azores at 40° northern latitude, and back, within 2 months’ time. The main driver of this extraordinary migration might be the need to molt skin and thus shed parasites.

Information on how the results will be applied:
This project resulted in fundamental knowledge of northern bottlenose whales including when,
where and why animals move; information that allows for a better assessment of the species’
vulnerability to manmade disturbance such as noise. This is especially important because levels of
underwater noise in their habitat are predicted to increase over the next decade; for example, with the opening a Trans-Arctic shipping route and the Finnafjord harbour. Knowing the areas that are important for these whales, when they are there and why, will lead to improve dynamic spatial
management of the marine environment and contribute to the conservation of the species. The
extensive underwater acoustics data set collected in this project provides a valuable baseline in the future for studying change in the underwater soundscape and ecosystem.

A list of the project’s outputs:
Haas, CE, Neubarth, BK, Miller, PJO, Hooker, SK, Svavarsson, J & Wensveen, PJ (2023). Acoustic
behaviour of northern bottlenose whales (Hyperoodon ampullatus) in Icelandic inshore waters.
Proceedings of the 10th Convention of the European Acoustics Association, Forum Acusticum 2023.
Wensveen, P, Kagerer, P, Haas, C, Neubarth, B & Marchon, T (2023). HYPMO-23 Cruise report.
Technical report.
Northeast Atlantic Northern Bottlenose Whale Photo-ID Catalogue. Version 1. Available online:
https://hypmo.org/catalogue/

Heiti verkefnis: Vaxandi hávaði í hafinu: er tilvist hinnar leyndardómsfullu andarnefju (Hyperoodon ampullatus) ógnað?/Noise in a changing ocean: a new threat to the elusive bottlenose whale (Hyperoodon ampullatus)?
Verkefnisstjóri: Paulus Jacobus Wensveen, Háskóla Íslands
Tegund styrks: Verkefnisstyrkur
Styrktímabil: 2020-2022
Fjárhæð styrks kr. 52.514.000
Tilvísunarnúmer Rannís: 207081