Population dynamics and production of the small copepod Oithona spp. in a subarctic fjord of West Greenland

• Published in: Polar Biology
• Main Authors: Zamora, Sara, Kjellerup, Sanne, Swalethorp, Rasmus, Saiz, Enric, Nielsen, Torkel G.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: Springer 2014
• Subjects: Fecundity; Production; Oithona; Greenland; Population dynamics; Small copepod; Polar Biology; Subarctic; Copepods
• Online Access: http://hdl.handle.net/10261/99744; https://doi.org/10.1007/s00300-014-1493-y

13 pages, 9 figures, 1 table The small cyclopoid copepod Oithona is widely occurring in polar areas; however, knowledge of its biology and ecology is very limited. Here, we investigate the population dynamics, vertical distribution, and reproductive characteristics of Oithona spp. from late winter to summer, in a subarctic fjord of West Greenland. During winter-early spring, the abundance of Oithona spp. was low (1.8 × 103 ind. m-2) and the population was mainly composed of late copepodites and adults, whereas in summer, abundance peaked and younger stages dominated (1.1 × 106 ind. m-2). In general, all stages of Oithona spp. remained in the upper 100 m, with nauplii exhibiting a shallower distribution. Although no general seasonal migration was found, a deeper distribution of the adult females in winter was observed. The mean clutch size of Oithona spp. varied from 16 to 30 eggs per female, peaking in summer. Egg production rates (EPR) were low in winter-early spring (0.13 ± 0.03 eggs female-1 day-1) and reached maximum values in summer (1.6 ± 0.45 eggs female-1 day-1). EPR of Oithona spp. showed a significantly positive relationship with both temperature and protozooplankton biomass, and the development of the population seemed to be appreciably affected by temperature. Oithona spp. remained active throughout the study, stressing the key importance of these small copepods in high-latitude ecosystems, especially in periods when larger copepods are not present in the surface layer. © 2014 Springer-Verlag Berlin Heidelberg This study was supported by the Greenland Climate Research Centre through the project 6505 to T.G. Nielsen. The research leading to these results has received funding from the European Commission FP7 EURO-BASIN (Grant Agreement: 264 933), and from the Spanish Ministry of Economy and Competitiveness through a Ph.D. fellowship (BES-2008-004231) to S. Zamora-Terol, and the project CTM2007-60052 to E. Saiz Peer Reviewed