RAS source details
Dale, T., S. Kaartvedt, B. Ellertsen & R. Amundsen. (2001). Large-scale oceanic distribution and population structure of Calanus finmarchicus, in relation to physical environment, food and predators. Marine Biology. 139 (3): 561-574.
83369
Dale, T., S. Kaartvedt, B. Ellertsen & R. Amundsen
2001
Large-scale oceanic distribution and population structure of Calanus finmarchicus, in relation to physical environment, food and predators.
Marine Biology
139 (3): 561-574.
Publication
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The investigation was carried out from 62°N to 73°N and from 14°E to 11°W in the Norwegian Sea during 19 June±12 July 1997. Regional di/erences in the phase of the seasonal development of the plankton community were evident, most pronounced across the Arctic front. In the Coastal and eastern Atlantic domains, post-bloom conditions prevailed, characterised by low chlorophyll a (chl a) levels and a phytoplankton assemblage dominated by coccolithophorids and small ¯agellates. During the study period, egg production rates of Calanus ®nmarchicus were low (<10 eggs female±1 day±1 ), older copepodite stages dominated, and the seasonal descent to deeper waters had started. In the Arctic domain, bloom conditions were evident by high chl a levels and a high abundance of large diatoms. Egg production rates were higher (a maximum of 29 eggs female ±1 day±1 ), but the dominance of stages CI±CIII indicated that considerable spawning had already occurred prior to the spring bloom. The seasonal descent had barely started. Both invertebrate and ®sh predators were most abundant in the Coastal and eastern Atlantic domains, with abundance strongly decreasing northwestwards. No tight relationship between total abundance of invertebrate or ®sh predators and that of C. ®nmarchicus was apparent. However, a weak, but signi®cant, relationship between abundance of young stages of chaetognaths and Euchaeta spp. versus young stages of C. ®nmarchicus was found, indicating that these invertebrate predators develop parallel to the development of the new cohort of C. ®nmarchicus. In early summer, C. ®nmarchicus had reached overwintering stages, and had started to accumulate in deeper waters in areas with the highest abundance of horizontally migratory planktivorous ®sh.
Calanus finmarchicus (Gunnerus, 1770) (additional source)
