| one publication added to basket [62408] | Stable isotopic compositions of overwintering copepods in the arctic and subarctic waters and implications to the feeding history
Sato, M.; Sasaki, H.; Fukushi, M. (2002). Stable isotopic compositions of overwintering copepods in the arctic and subarctic waters and implications to the feeding history. J. Mar. Syst. 38(1-2): 165-174. http://dx.doi.org/10.1016/s0924-7963(02)00175-6
In: Journal of Marine Systems. Elsevier: Tokyo; Oxford; New York; Amsterdam. ISSN 0924-7963; e-ISSN 1879-1573, more
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| Keywords |
Body conditions
Composition > Biochemical composition
Food preferences
Organic matter > Particulates > Particulate organic matter
Overwintering
Calanus glacialis Jaschnov, 1955 [WoRMS]; Copepoda [WoRMS]; Metridia longa (Lubbock, 1854) [WoRMS]
PNE, Barents Sea [Marine Regions]
Marine/Coastal |
| Author keywords |
copepods; stable isotope; feeding history; lipids; polar seas |
| Authors | | Top |
- Sato, M.
- Sasaki, H.
- Fukushi, M.
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| Abstract |
Highly abundant zooplankton dominated by copepods was found in the upper 200 m water column off the west of Spitsbergen in winter, although copepods in high-latitude environments during the overwintering period are known to reside in deep waters. We examined the possible feeding activities of these surface dwelling, overwintering copepods through their stable isotope compositions (15N and 13C), and their internal lipids. The differences in the 15N values (15N enrichment factor) between the particulate organic matter (POM) at the surface layers and the dominant copepods in winter showed that the averaged 15N enrichment factor in Calanus glacialis (+2.7‰) and Metridia longa (+2.8‰) were higher than that in Calanus finmarchicus (+1.7‰). This suggests that C. glacialis and M. longa might be occasional omnivorous feeders, because the 15N enrichment factor of these two copepods were relatively close to the previously reported value (e.g. +3.4±1.1‰, [Geochim. Cosmochim. Acta 48 (1984) 1135]) for a stepwise increase of the value with the food chain. The estimated lipid isotopic ratios (13C) of C. finmarchicus and M. longa tended to decrease with the decreasing lipid contents (lipid carbon/total carbon), suggesting that some lipid components with heavy isotopes were removed from the total lipids. The isotopic changes of lipids with the lipid contents probably reflect the metabolic processes of lipid utilization of arctic and subarctic copepods during the overwintering period. |
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