Common macrofaunal dominant species in the sediments of some north Norwegian and Svalbard glacial fjords

Abstract

Based on own data from the north Norwegian Holandsfjord and two Svalbard fjords (the Van Mijenfjord and the Raudfjord), and literature data from three other fjord regions at Svalbard, soft-bottom communities are analysed and discussed in order to identify common and numerically dominant species in glacier-derived fine-particulated inorganic impacted sediments. The most abundant common taxa in the inner and presumed most glacier-impacted parts of the Holandsfjord, the Van Mijenfjord and the Raudfjord were the surface-feeding detrivorous polychaetes Laonice cirrata, Chaetozone setosa, Myriochele sp. and Terebellides stroemi, the subsurface-feeding detrivorous polychaetes Scoloplos armiger, Ophelina acuminata, Maldane sarsi and Praxillella spp., the carnivorous polychaete Lumbrineris sp., and the subsurface detrivorous bivalves Yoldiella lenticula, Nuculoma tenuis, Nuculana pernula and Thyasira. In addition to these taxa, results from the other reviewed surveys in Svalbard indicate that glacier-influenced fjords may also be numerically dominated by the presumed surface-feeding detrivorous polychaete Levinsenia gracilis, the subsurface-feeding detrivorous polychaete Heteromastus filiformis, the carnivorous polychaetes Harmothoe and Aglaophamus malmgreni, and the subsurface-feeding detrivorous bivalves Yoldiella frigida, Yoldiella nana and Portlandia arctica. The generally quite frequent Heteromastus filiformis, Maldane sarsi and Praxillella, which feed head down at some depth in the sediments, may contribute, through selective feeding and recycling of organic carbon by depositing faecal products at the sediment surface, to the maintenance of relatively high faunal abundances in the organically poor sediments of glacier-influenced fjords.