Thermal limits of krill species from the high-Arctic Kongsfjord (Spitsbergen)

Abstract

MEPS Marine Ecology Progress Series Contact the journal Facebook Twitter RSS Mailing List Subscribe to our mailing list via Mailchimp HomeLatest VolumeAbout the JournalEditorsTheme Sections MEPS 535:89-98 (2015) - DOI: https://doi.org/10.3354/meps11408 Thermal limits of krill species from the high-Arctic Kongsfjord (Spitsbergen) Kim Huenerlage*, Friedrich Buchholz Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research, Am Handelshafen 12, 27570 Bremerhaven, Germany *Corresponding author: kim.huenerlage@awi.de ABSTRACT: The high-Arctic Kongsfjord is mainly influenced by cold Arctic water, but also receives input of warmer water from the Atlantic. In recent years, the proportion of Atlantic inflow from the south has increased. Concurrently, one temperate-boreal (Meganyctiphanes norvegica) and one subtropical-temperate (Nematoscelis megalops) krill species are now regularly found in the Kongsfjord, in addition to the previously prevailing arcto-boreal species Thysanoessa inermis and T. raschii. In light of the recent changes in these species’ biogeographic distributions, we compared their physiological tolerances. Using non-invasive optical oxygen sensors, respiration measurements served to characterize metabolic responses to temperature variations. The 2 Thysanoessa spp. appeared more cold-stenotherm than the other 2 krill species: the upper level of their respiratory capacity was reached at 12°C and they were less tolerant of decreasing oxygen concentrations. This finding is consistent with their arcto-boreal distribution. In contrast, M. norvegica and N. megalops exhibited higher tolerance to temperature changes, robust nutritional condition and sexual maturity. Such physiological plasticity may explain the recent northward expansion of these species’ geographic range. KEY WORDS: Metabolic rates · Respiration · Thysanoessa inermis · Thysanoessa raschii · Meganyctiphanes norvegica · Nematoscelis megalops Full text in pdf format Supplementary material PreviousNextCite this article as: Huenerlage K, Buchholz F (2015) Thermal limits of krill species from the high-Arctic Kongsfjord (Spitsbergen). Mar Ecol Prog Ser 535:89-98. https://doi.org/10.3354/meps11408 Export citation RSS - Facebook - Tweet - linkedIn Cited by Published in MEPS Vol. 535. Online publication date: September 15, 2015 Print ISSN: 0171-8630; Online ISSN: 1616-1599 Copyright © 2015 Inter-Research.