Associated data to 'Variability in nitrogen-derived trophic levels of Arctic marine biota': Arctic trophic levels

Data on stable nitrogen isotopes for Arctic species, and corresponding trophic level parameters (See equation 1: δ15NBaseline, TLbaseline, Δ15N), were collected by conducting an extensive literature search using the Web of Science. 〖TL〗_consumer=〖TL〗_baseline+(〖δ^15 N〗_consumer- 〖δ^15 N〗_baseline+ ∆D)/∆15N [1] We combined search strings related to stable isotope analysis (e.g. ‘stable isotope analysis’ and ‘nitrogen stable isotopes’) and biota in the European, Canadian and Alaskan Arctic using general terms (e.g. “Arctic biota”) as well as species names (e.g. ‘Ursus maritimus’ and ‘Calanus hyperboreus’). Stable isotope data were either extracted from tables or manually digitized using DigitizeIt (http://www.DigitizeIt.de/). Only stable isotope data sampled from April until October and after the year 2000 were included in the dataset, due to a lack of data outside this timeframe. Distinction was made between benthic and pelagic food webs. Although additional organism-specific and sample-specific parameters (i.e. age, length, body weight, date and sampling tissue) were included in the database, no further sub-setting was based on these parameters. The initial search resulted in 65 useful articles and reports, encompassing 148 species, covering four distinct Arctic areas: Alaskan Beaufort Sea, Canadian Beaufort Sea, Canadian Archipelago and Svalbard. Data pertaining to unique species (i.e. only observed in one of the four areas) were disregarded, resulting in a dataset comprising 107 species (29 pelagic, 78 benthic species), covering approximately 2400 individual records