Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2017

Erindi/veggspjald / Talk/poster E4

Trophic relationships and the role of Calanus in the oceanic ecosystems south and north of Iceland

Höfundar / Authors: Hildur Pétursdóttir

Starfsvettvangur / Affiliations: Hafrannsóknastofnun (Marine and Freshwater Research Institute)

Kynnir / Presenter: Hildur Pétursdóttir

The waters south and north of Iceland vary greatly both oceanographically and biologically with the rather stable and warm Atlantic waters south and west of Iceland and the more variable and cold Arctic and sub-Arctic waters, north and east of Iceland. The aim of this study was to increase the knowledge on the role of Calanus copepods and trophic relations of the key components of the oceanic ecosystems south-west and north of Iceland. The trophic relationships and energy transfer to higher trophic levels were estimated by using fatty acid trophic markers and by applying stable isotopes of carbon and nitrogen. The energy rich Calanus species are key links between primary producers and higher trophic levels in the Icelandic waters. The Calanus species dominate the zooplankton biomass around Iceland and their markers (20:1n9 and 22:1n11) are found in high amount in animals at higher trophic levels. Calanus finmarchicus plays important role as a forage species in the Atlantic water south-west of Iceland while its high importance is replaced by the larger lipid rich C. hyperboreus in the Arctic and sub-Arctic waters north of Iceland. Even though Calanus based food-web is the main driver in both areas, there exist a pathway where Calanus species are of less importance and the energy is channeled via euphausiids to higher trophic levels. This study presents novel important knowledge on the food web structures and carbon flow in Icelandic waters.