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Játtað í: 2021 Granskingarøki: MARiNAO Verkætlanarslag: PhD Verkætlanarheiti: TOPLINK - Marine top predators as ecosystem indicators in the central North Atlantic Játtanarnummar: 8010 Verkætlanarleiðari: Mads Peter Heide-Jørgensen Stovnur/virki: Greenland Institute of Natural Resources Aðrir luttakarar: Bjarni Mikkelsen, Fernando Ugarte, Eva Garde, Lise Helen Ofstad, Havstovan Verkætlanarskeið: Original: 01/01/2022-31/01/2024 Final: 01/06/2022-31/10/2025 Samlaður kostnaður: 6.357.987 Stuðul úr Granskingargrunninum: 3.973.000 Verkætlanarlýsing: Original This project will use top-predators as indicators for the status and long-term trend of the North-Atlantic ecosystem, with focus on the Greenland-Iceland-Faroe-Scotland Ridge, and explore impact and feedback mechanisms manifested in the indicators. The project will study the ecological role of three common but overlooked top-predators, pilot whale, dolphin and killer whale, of major importance for the central North Atlantic ecosystem. The three whales consume millions of tons of prey every year but the impact from the predation has not been studied before, and the three species are showing signs of changes in distribution that are related to large scale oceanographic changes. Importantly, they are also simultaneously subject to opportunistic hunting activities in both East Greenland and the Faroe Islands, which call for new and updated knowledge. The migrations, stock identity, diving and feeding behavior will be studied with satellite telemetry and the information will be compared to remote sensing data of sea surface temperatures, chlorophyll concentrations and food availability. Samples of the hunt will be collected to estimate feeding habits, reproduction, age and growth, and tissue samples will be sampled for genetic and pollutant analyses. Teeth from historical collections and from modern hunting will be studied with laser ablation methods to identify elemental depositions in order to reveal traces of ecosystem changes over time. We furthermore seek collaboration with a digital game that will illustrate climate models, detect past and future tipping points, and their impact on ecosystem and marine mammals in the North Atlantic. Final The project used satellite tags and stomach samples to assess how oceanographic conditions shape the behaviour of pilot whales, dolphins and killer whales along the Greenland–Iceland–Faroes Ridge. We showed that white-sided dolphins can undertake cross‑basin migrations at steady speeds over several days, highlighting the Irminger Sea as an important autumn feeding area linked to deep‑mixing productivity, and the Faroe–Shetland Channel as a key area in the east. Their trans‑Atlantic movements support treating them as a single stock across the central and eastern North Atlantic. Dolphins separated soon after tagging, consistent with their fluid social structure. Pilot whales showed regional differences in movement and habitat use, likely driven by foraging ecology and oceanographic conditions. Despite genetic connectivity, ecological differentiation appears possible. Pilot whales in the Faroe Islands used large oceanic ranges and deep waters influenced by the subpolar front, while those in East Greenland and Iceland relied heavily on the continental shelf. East Greenland pilot whales had a small summer range in habitat that was inaccessible 25 years ago due to ice cover. In the Faroe Islands, white-sided dolphins fed mainly on blue whiting, Norway pout and some squid. Pilot whales there have relied on squid for 40 years, although fish have increased in their diet over time. In Greenland, white-beaked dolphins specialise on capelin, while pilot whales prefer squid, and killer whales feed mainly on harp seals. Storage and access rights to collected data: Data is available upon request and in the publication’s supplementary material. Data requests can be addressed to the TOPLINK consortium, the PhD student, FAMRI or GINR. Støða: Liðug << Back |
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