Spatial variability of carbon (δ¹³C) and nitrogen (δ^15N) stable isotope ratios in an Arctic marine food web

Abstract

Stable isotopes of carbon (δ 13 C) and nitrogen (δ 15 N) were used to examine trophic structures in an arctic marine food web at small and large spatial scales. Twelve species, from primary consumers to Greenland shark, were sampled at a large spatial scale near the west and east coasts of Greenland. There was a significant positive latitudinal effect on δ 15

Assessing the diet of North American Atlantic salmon (Salmo salarL.) off the West Greenland coast using gut content and stable isotope analyses

“…In contrast, SIA data, which incorporate dietary assimilation signals over a period of months, noted statistically significant absolute differences among sites in δ 13 C' across all 3 years, and among sites in the δ 15 N data in 2011. Such differences could be related to differential inshore and offshore feeding for δ 13 C', and variation in baseline δ 15 N along the West Greenland coast owing to the impact of different water masses mixing, changes in open water period, or temperature (Hansen, Hedeholm, Sünksen, Christensen, & Grønkær, ). Spatial variations in potential sea surface temperature, as well as variations in the presence and mixing of water masses along the West Greenland coast (particularly Polar Water, Irminger Water and Modified Irminger Water) have been reported (Ribergaard, , , ).…”

“…Statistical testing of δ 15 N and δ 13 C' values indicated significant longer‐term temporal variation, potentially as a result of these variations in prey items among years, as well as interannual differences in inshore–offshore feeding (Hansen et al., ; Rikardsen & Dempson, ). It is also possible that physical oceanic differences among years such as temperature, the type of water masses present at each site, and changes in the open water period are responsible for stable isotope variation (Hansen et al., ). Climate‐induced variation in prey resources has been similarly suggested as the reason for the inter‐annual variation in the diet of Pacific salmon ( Oncorhynchus spp.)…”

Marine trophic niche use and life history diversity among Arctic charrSalvelinus alpinusin southwestern Greenland

“…To correlate Arctic charr δ 13 C and δ 15 N signatures to the signatures of their potential marine diet, marine prey stable isotope values for polar cod ( Boreogadus saida (Lepechin)), Atlantic cod ( Gadus morhua (L.)), American plaice ( Hippoglossoides platessoides (Fabricius)), capelin ( Mallotus villosus (Cuvier)), krill ( Thysanoessa raschii (SARS)), copepod ( Calanus finmarchius (Gunnerus)) and shrimp ( Pandalus borealis (Krøyer))) were obtained from Hansen et al . (), while data on amphipods ( Thermisto spp. ), armhook squid ( Gonatus fabricii (Lichtenstein)) and sandlance ( Ammodytes spp.)…”

“…Krøyer))) were obtained fromHansen et al (2012), while data on amphipods (Thermisto spp. ), armhook squid (Gonatus fabricii (Lichtenstein)) and sandlance (Ammodytes spp.)…”

“…were obtained fromDixon et al (2019) andPower (unpublished data). In western Greenland, δ 13 C and δ 15 N signatures change with latitude(Hansen et al, 2012), so samples of potential marine prey from the Nuuk area(Dixon et al 2019;Hansen et al, 2012; Power unpublished data) were related to Arctic charr from the Kapisillit watercourse, while samples from the Qaqortoq area(Hansen et al, 2012; unpublished data) were related to Arctic charr from the Equalit and Quinqua watercourses.…”