Data supporting Comparison of feeding niches between Arctic and northward moving sub-Arctic marine mammals in Greenland

Data supporting the paper:

Land-Miller, H., A. Roos, M. Simon, R. Dietz, C. Sonne, S. Pedro, A. Rosing-Asvid, F. Rigét, and M. McKinney. 2023. Comparison of feeding niches between Arctic and northward moving sub-Arctic marine mammals in Greenland. Marine Ecology Progress Series.

This data is in five files:

1. greenland_marmam_metadata.csv contains metadata for all samples used in this project, including sample identifiers:

• Sample: unique sample ID per individual animal
• Species

and details of collection, including Year, Location (general area), Lat, Long, and Date. It also includes other data on the animal (Sex, Age, Length), when available, as well as the co-author who provided the sample to the project (Sample sender) and the tissues available/analyzed for each individual (Tissues received).

2. all_sample_locations.csv includes latitude/longitude of each sample for mapping. Latitude and longitude are consistent with the full metadata file when coordinates were available, and estimated based on general sampling area (Location or Area) when not. The variable estimate denotes samples for which coordinates were estimated.

3. fatty_acids_greenland_marmams.csv contains fatty acid data for all samples. Variables 8:00 to 24:1n9 represent the proportion of each individual fatty acid, out of total fatty acids in that sample. Data are represented as whole number percents (i.e., 10 = 10% and all fatty acids sum to 100 for each sample). 

4. CNS_greenland_McGill.csv contains bulk stable isotope data for all samples analyzed at McGill. In addition to Sample and Species, this includes:

• treatment: whether a sample was lipid-extracted (LE) or non-lipid-extracted (nLE) prior to analysis
• d15N: stable isotope ratio δ¹⁵N
• d13C: stable isotope ratio δ¹³C
• d34S: stable isotope ratio δ³⁴S
• perc.C: mass percent of carbon in the sample
• perc.N: mass percent of nitrogen in the sample
• perc.S: mass percent of sulfur in the sample
• C.N.ratio: mass ratio of carbon to nitrogen in the sample 

5. CN_greenland_nLE_copenhagen.csv contains stable isotope data for non-lipid-extracted samples analyzed at the University of Copenhagen for δ¹³C and δ¹⁵N. Variables treatment, d13C, and d15N are consistent with CNS_greenland_McGill.csv.