Líffræðifélag Íslands - biologia.is
Líffræðiráðstefnan 2023
Höfundar / Authors: Guðmundur Guðmundsson (1), Tomas Cedhagen (2), Tom Andersen (3) Aarhus University, Department of Biology, Section of Aquatic Biology, Building 1135, Ole Worms allé 1, DK-8000 Aarhus C, Denmark 3.
Starfsvettvangur / Affiliations: (1) Icelandic Institute of Natural History, Urridaholtsstraeti 6-8, IS-210 Gardabaer, Iceland. (2) Aarhus University, Department of Biology, Section of Aquatic Biology, Building 1135, Ole Worms allé 1, DK-8000 Aarhus C, Denmark. (3) University of Oslo, Department of Biosciences, The faculty of Mathematics and Natural Sciences, P.O. Box 1066 Blindern, N-0316 Oslo, Norway
Kynnir / Presenter: Guðmundur Guðmundsson
The nodosariind species are among the few survivors of the Last Global Extinction in the deep sea that occurred during the late Pliocene–middle Pleistocene interval (3.6–0.13 Ma), when over 20% of large (<10 mm) cylindrical Foraminifera, with peculiar mouth structure, selectively went extinct. Knowledge of these extant nodosariinid species in the North Atlantic was limited mainly to a few studies in the late 19th and early 20th centuries. Later and recent studies have emphasized quantitative samples of a few cm3 which rarely collects these larger species. This study analysed material from 879 dredging devices that collects large sample volume. Nodosariinae occurred in 492 samples, comprising 7,598 specimens of about 415,000 specimens of all picked foraminifera. Taxonomy of 14 little-known nodosariinid species was revised and ordination analysis of species distributions is correlated with temperature and salinity gradients within sampling area (753.000 km2) north and south of the Greenland-Scotland Ridge. Eight species are restricted to temperate waters (>2°C) south off Iceland: four species occur mainly north of Iceland; and two species have wide tolerance range for physical variables and are widely distributed within the sampling area. The results shed new light on the habitat preferences of these species and aids in geological interpretations of past environmental changes.