Dataset: Fatty acid composition of McMurdo Benthos

Methodology: 
Sample collection and field treatment: Sediment cores were collected at the “Jetty” dive site location in September, November and February 2012-2013.  These were sieved on a 300-micron sieve to collect macrofauna and members of the abundant species Spiophanes tcherniai (a spionid polychaete) and Edwarsia spp.  (a sand anemone) were picked under a dissecting microscope and placed in filtered seawater overnight to allow gut evacuation. At this point, individuals were frozen separately at -80 C prior to lipid extraction.

Sampling and analytical procedures:
Samples were freeze-dried and their lipids extracted using one-step extraction-transesterification procedure of Lewis et al. (2000) as used in Thurber (2014). In brief, individuals were placed in pre-cleaned and extracted sample vials, heated to 90 deg. C for one hour in a solution of methanol, chloroform, and hydrochloric acid (10:1:1 by volume) before cooling and water added to break the phase.  Fatty acid methyl esters (FAMEs) were extracted in sequential addition of hexane:chloroform (4:1) and water further removed through the addition of sodium sulfate.  The FAMEs were then ready for quantification on a GC-FID. 

Isotopic analysis was measured on a Thermo 1310 gas chromatograph with a Flame Ionization detector using a TR-WaxMS column (30mx 0.32mm x 0.25 um).  Peak identification was by comparison to known standards (for example the Supulco 32 FAME mixture).