Watershed Symposium 2022

Utah Lake is such an important part of Utah and should be well managed. Part of that management is studying the fish within and determining if those fish could adversely effect those who fish at the lake. In our study we are looking at trace metal content specifically since many trace metals like Arsenic can severely effect human beings.

Utah Lake (Central Utah, USA) is a shallow, hypereutrophic lake, and the third largest freshwater body west of the Mississippi River. It serves as the main irrigation source for the surrounding area which contains more than 600,000 people. Utah Lake is surrounded by multiple anthropogenic and natural sources of trace metal pollution that affect the fish which are consumed by residents. The purpose of the study is to analyze the content of selected trace metals in four popular sport fish: White Bass (Morone chrysops), Black Bullhead (Ameiurus melas), Northern Pike (Esox lucius), and Common Carp (Cyprinus carpio). One hundred fifty-nine fish were collected from the Provo Bay area of Utah Lake, divided into male and female, dissected, and separated into two sets of tissues (offal and filet). The samples were weighed (0.0005g) in replicates of three, digested in the MARS using EPA method 3015, and analyzed in the ICP-OES for trace metal (As, Cd, Cr, and Pb) content. Statistical analysis was performed using the R programming language. Results reveal that trace metal levels present in the fish tested exceeded standards set by the European Union; As was detected at 0.295 ppm (p<0.0001), Cd at 0.040 ppm (p<0.100), and Pb at 0.415 ppm (p<0.001). For the most part trace metal levels were higher in the offal tissues compared to the filets. For example, Pb, Cd, and Cr levels were moderate to highly significant (p<0.01 to p<0.0001) and found in concentrations of 0.360 ppm, 0.020 ppm, and 0.280 ppm in the filets and 0.63 ppm, 0.105 ppm, and 0.82 ppm in the offals, respectively. In contrast with the overall trend, Arsenic in the filets of White Bass, Common Carp, and Northern Pike are 2.27, 1.45, and 1.44 times higher than in the offal tissues. Northern Pike also broke the trend in Lead levels where the filets had a concentration of 0.340 ppm versus 0.240 ppm in the offal tissues. These results, while preliminary, show that people who eat certain fish from Utah Lake may be at risk of exposure to toxic levels of trace metals. Furthermore, this study could help regulatory agencies manage trace metal release into Utah Lake.