Assessing Marine Endocrine-Disrupting Chemicals in the Critically Endangered California Condor: Implications for Reintroduction to Coastal Environments

Coastal reintroduction sites for California condors (Gymnogyps californianus) can lead to elevated halogenated organic compound (HOC) exposure and potential health impacts due to the consumption of scavenged marine mammals. Using non-targeted analysis based on comprehensive two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GCXGC/TOF-MS), we compared HOC profiles of plasma from inland and coastal scavenging California condors from the state of California (CA), and marine mammal blubber from CA and the Gulf of California off Baja California (BC), Mexico. We detected more HOCs in coastal condors (32 +/- 5, mean number of HOCs +/- SD, n = 7) than in inland condors (8 +/- 1, n = 10) and in CA marine mammals (136 +/- 87, n = 25) than in BC marine mammals (55 +/- 46, n = 8). Sigma DDT-related compounds, Sigma PCBs, and total tris(chlorophenyl)methane (Sigma TCPM) were, respectively, similar to 7, similar to 3.5, and similar to 148 times more abundant in CA than in BC marine mammals. The endocrine-disrupting potential of selected polychlorinated biphenyls (PCB) congeners, TCPM, and TCPMOH was determined by in vitro California condor estrogen receptor (ER) activation. The higher levels of HOCs in coastal condors compared to those in inland condors and lower levels of HOC contamination in Baja California marine mammals compared to those from the state of California are factors to consider in condor reintroduction efforts.

Automated summary

Coastal reintroduction sites for California condors can result in increased exposure to halogenated organic compounds. The plasma of coastal condors contains more HOCs compared to inland condors, and the HOC contamination in marine mammals from California is higher than in those from Baja California.