Fatty acids in thirteen Wisconsin sport fish species

Abstract

Fish are an easily-obtainable source of low-fat protein and fatty acids (FAs), particularly beneficial omega-3 and omega-6 polyunsaturated fatty acids (PUFAs). While data concerning FAs in marine and/or farmed fish are readily available, data regarding spatial variation in FA concentrations in wild, freshwater sport fish species are lacking. To begin addressing this data gap and to provide the general public with more comprehensive consumption advice, we analyzed 13 sport fish species from several of Wisconsin's inland and Great Lakes waters for 16 FA analytes. FA concentrations were compared between species, trophic levels, and with research previously published on freshwater species in our study. We found that fish length was positively correlated with total FA content (r=0.617, P<0.0001) for the whole dataset, but not for any individual species. Salmonids generally contained the highest total FAs while percids and centrarchids contained the lowest concentrations. However, diet was a better predictor of FA concentration than taxonomic family. Species that were completely or partly piscivorous contained higher PUFAs (P≤0.001) than those that consumed primarily invertebrates. We also found that Wisconsin sport fish generally contained lower concentrations of monounsaturated and saturated FAs than those found in reference studies, whereas omega-3:omega-6 FA ratios and concentrations of omega-6 FAs were largely similar. Incorporating beneficial FA data into existing fish consumption advice is a challenge at this time, and it is recommended that additional FA information be obtained with the goal of quantitatively incorporating benefits into risk assessments and advisory protocols.