Publication Date:
2023-10-28
Description:
Stable isotope (SI) ratios of carbon (d13C) and nitrogen (d15N) were measured in omnivorous and carnivorous deep-sea copepods of the families Euchaetidae and Aetideidae across the Atlantic sector of the Southern Ocean to establish their trophic positions. Due to high and variable C/N ratios related to differences in lipid content, d13C was corrected using a lipid-normalisation model. d15N signals ranged from 3.0-6.9 per mil in mesopelagic species to 7.0-9.5 per mil in bathypelagic congeners. Among the carnivorous Paraeuchaeta species, the epi- to mesopelagic species Paraeuchaeta antarctica had lower d15N values than the mesopelagic P. rasa and bathypelagic P. barbata. The same trend was observed among omnivorous Aetideidae, but was not significant. In the most abundant species P. antarctica, individuals from the western Atlantic had higher d13C and d15N values than specimens at the eastern stations. These longitudinal changes in d13C and d15N values were attributed to regional differences in hydrography and sea surface temperature (SST), in particular related to a northward extension of the Antarctic Polar Front (APF) at the easternmost stations. The results indicate that even in a mesopelagic carnivorous species, the changes in surface stable isotope signatures are pronounced.
Keywords:
ANT-XXIII/5; AWI; Carbon/Nitrogen ratio; Date/Time of event; Depth, bottom/max; Depth, top/min; Element analyser isotope ratio mass spectrometer (EA-IRMS); Elevation of event; Event label; Latitude of event; Life stage; Longitude of event; MSN; Multiple opening/closing net; Number of individuals; Polarstern; Priority Programme 1158 Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas; PS69; PS69/342-1; PS69/343-1; PS69/344-1; PS69/345-1; PS69/346-1; PS69/347-1; PS69/348-1; PS69/349-1; PS69/350-1; PS69/351-1; Species; SPP1158; Station label; δ13C; δ15N
Type:
Dataset
Format:
text/tab-separated-values, 488 data points
Permalink
