Short communicationMaternally transferred mercury in wild largemouth bass, Micropterus salmoides

- Previous work suggests maternal Hg transfer in teleosts is consistently low.
- We provide evidence that teleosts can have high maternal Hg transfer.
- Females with low Hg had similar and low concentrations of Hg in their eggs.
- Females with high Hg had Hg in eggs that increased with somatic tissue Hg.
- Egg Hg from high Hg females exceeded adverse effect levels.

Maternal transfer of mercury in fish represents a potential route of elimination for adult females and a risk to developing embryos. To better quantify maternal transfer, we measured Hg in female largemouth bass (Micropterus salmoides) muscle and eggs from six waterbodies. Mercury in eggs from two waterbodies exceeded a US federal screening level (0.3 μg g−1) and was likely high enough to cause adverse reproductive effects. We found a curvilinear relationship between female and egg Hg. Fish with <0.37 μg g−1 Hg had low levels of Hg in eggs; those with Hg >0.37 μg g−1 showed a direct relationship between egg and muscle Hg (Log10 egg Hg = −1.03 + 1.18 * log10 muscle tissue Hg + 2.15 * (log10 muscle tissue Hg + 0.35)2). We also report higher maternal transfer (0.2-13.2%) and higher ratios of egg to muscle tissue Hg (4-52%) and egg to whole body Hg concentrations (7-116%) than previously observed for teleost fish.