Comprehensive assessment of legacy organic contaminants and trends in lake trout from Cayuga Lake, New York: 2011–2017

Abstract

A seven-year assessment of lake trout contaminants and statistical trend modeling was conducted on Cayuga Lake, New York as the reference monitoring site for the USEPA Great Lakes Fish Monitoring and Surveillance Program (GLFMSP). In all, over 200 individual compounds including polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), organochlorine pesticides (OCPs), polychlorinated napthalenes (PCNs), polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs) were monitored for the 2011–2017 study period. Legacy contaminants such as PCBs, OCPs, and PBDEs dominate the whole-fish lake trout contaminant profile in the 24–147 ng/g mean concentration range. Total dioxin-like contaminants monitored included PCDD/Fs, CP-PCBs, and PCNs with a mean concentration range of 2.0–516 pg/g. TEQ concentrations for the dioxin-like compounds ranged between 0.3 and 5.3 pg-TEQ/g, and total TEQ averaged 7.2 pg-TEQ/g for whole-fish lake trout. Contaminant trends were modeled using log-linear correlations for both whole-fish lake trout and lake trout eggs. All select compounds modeled for whole-fish lake trout showed significant decreases (average −53.4%) over the study period. Tissue residue guidelines for the protection of wildlife were uniformly exceeded for both mammals and birds based on mean 2011–2017 total TEQ concentrations measured. All lake trout skin-on fillets from Cayuga Lake analyzed exceed the USEPA human health screening value of 0.15 pg-TEQ/g-ww. Whole-fish lake trout from Cayuga Lake have significantly lower mean total TEQs (6.5 pg-TEQ/g) as compared with the average total TEQ in the Great Lakes (range: 21.9–50.8 pg-TEQ/g) (U = 10.000, p < 0.001), although rates of contaminant decline, contaminant ratios, and half-life (t1/2) are comparable.