New publication: Parental crude oil exposure shapes offspring development in Atlantic cod
A new study published in Marine Pollution Bulletin reveals that crude oil exposure during reproduction affects Atlantic cod offspring in profoundly different ways depending on whether the mother or father was exposed — with maternal exposure proving lethal to embryos and paternal exposure linked to delayed larval mortality.
We are excited to share a new publication from our team, now out in Marine Pollution Bulletin. The study, led by PhD candidate Claudia Erhart, investigated how exposure of adult Atlantic cod to crude oil during their reproductive period affects the next generation — and whether mothers and fathers contribute differently to these outcomes.
Using in vitro cross-fertilization, the team created four offspring groups from exposed and unexposed parents, and followed embryonic development from fertilization to hatching using RNA sequencing, chemical analyses, and phenotypic assessments. The results reveal striking differences between maternal and paternal exposure pathways. Offspring from exposed mothers failed to survive to hatching: their eggs were smaller, carried maternally transferred petroleum compounds, and showed severe suppression of genes essential for early embryonic development, including the critical maternal-to-zygotic transition. Paternal exposure, in contrast, had minimal effects on early gene expression and morphology — but was associated with reduced survival in the larval stage, pointing to subtle, delayed effects potentially mediated through epigenetic mechanisms.
These findings highlight the importance of considering adult reproductive exposure and sex-specific parental contributions when assessing ecological risks of oil contamination in the marine environment.
This study represents a key milestone in Claudia's PhD research and is part of the TOXIGEN project (Research Council of Norway, grant #334541) and the FRAM Centre flagship project PARENTOX (2020).
Congratulations to the entire team!
Full reference: Erhart, C., Nahrgang, J., Odei, D.K., Frantzen, M., Sørensen, L., Creese, M.E., Puvanendran, V., Hansen, Ø.J., Hansen, B.H., Meador, J.P., & Yadetie, F. (2026). Maternal and paternal crude oil exposure differentially shapes early developmental transcriptomes and survival outcomes in Atlantic cod (Gadus morhua). Marine Pollution Bulletin, 226, 119374. https://doi.org/10.1016/j.marpolbul.2026.119374