Alaska Blackfish (ALBL)

Alaska Blackfish (ALBL) Amphipod (AMPH) Arctic Flounder (ARFL) Arctic Grayling (ARGR) Broad Whitefish (BRWH) Fairy Shrimp (FAIR) Least Cisco (LECI) Ninespine Stickleback (NIST) Rainbow Smelt (RASM) Slimy Sculpin (SLSC) Threes-spined Stickleback (THST)

Online Resource 1: Results from prey-on-prey simulations using Quantitative Fatty Acid Statistical Analysis (QFASA) methods. The prey-on-prey analysis is an iterative process (in our case performed 100 times) where the prey data are randomly split into two sets for each prey type – a set that acts as the prey data and a set that is modeled as the predator data without calibration coefficients (Iverson et al. 2004). The simulation output can be used to determine how well QFASA can distinguish among prey item types based on how well QFASA correctly classifies the FA signatures of each prey type. Prey codes include: ALBL – Alaska blackfish (Dallia pectoralis), AMPH – amphipod species, ARFL – Arctic flounder (Liopsetta glacialis), ARGR – Arctic grayling (Thymallus arcticus), BRWH – broad whitefish (C. nasus), FAIR – fairy shrimp species, LECI – least cisco (Coregonus sardinella), NIST – ninespine stickleback (Pungitius pungitius), RASM – rainbow smelt (Osmerus mordax), SLSC – slimy sculpin (Cottus cognatus), , and THST – three-spined stickleback (Gasterosteus aculeatus).