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Associations Between Urogenital Carcinoma and DECA-BDE (BDE-209) Among wild California Sea Lions (Zalophus californianus) and Steller Sea Lions (Eumetopias jubatus)

Dec 1, 2023


Urogenital carcinoma (UGC) is prevalent among California sea lions (Zalophus californianus), while less is known concerning UGC among Steller sea lions (Eumetopias jubatus). Our objective was to investigate associations between UGC and polybrominated diphenyl ethers (PBDEs) among both sea lion species. Twenty-nine California sea lions and 20 Steller sea lions were lethally removed from the Columbia River Basin, Oregon, USA between 2020 and 2021, under Section 120 of the Marine Mammal Protection Act. UGC was diagnosed through gross necropsy and histopathology. Forty PBDE congeners were analyzed in blubber, including BDE-209, a potential carcinogen. Twenty (69 %) California sea lions and one (5 %) Steller sea lion were diagnosed with UGC. All cases were identified as early stage UGC, aside from one California sea lion with more advanced stage UGC. Among California sea lions, associations between PBDEs and UGC were analyzed using logistic regression. In the adjusted model, BDE-209 (log2-transformed) was associated with increased odds of UGC [Odds Ratio (OR): 4.68, 95 % confidence interval: 1.04, 21.0, OR p-value = 0.044). This is the first study to report BDE-209 concentrations in sea lion blubber. The percentages of California and Steller sea lions diagnosed with UGC were higher than expected for wild (non-stranded) sea lions. Our results suggested blubber BDE-209 was potentially associated with UGC in California sea lions in the Columbia River Basin.

Other keywords: toxic contaminants


Sarah Rothenberg, Brianna Beechler, Julia Burco, Samantha Rae, Sheanna Steingass, Dianne Barton, Jennifer Johns, Duncan Russell, Kristen Deignan, Megan Blackledge, and Autumn Nation


Rothenberg, S.E., B.R. Beechler, J.D. Burco, S. Rae, S.M. Steingass, D. Barton, J.L. Johns, D.S. Russell, K. Deignan, M.M. Blackledge, A. Nation. 2023. Associations between urogenital carcinoma and DECA-BDE (BDE-209) among wild California Sea lions (Zalophus californianus) and Steller Sea lions (Eumetopias jubatus). Science of the Total Environment 900:166412. Online at 10p.



Report No.


Media Type

Journal Article