DOM consumption and demethylation of MeHg as potential drivers of low MeHg in Mediterranean Sea sponges and benthic fish: a modeling perspective

Amptmeijer, David J.; Hanz, Ulrike; Schrum, Corinna; Bieser, Johannes

doi:10.5194/bg-23-4057-2026

Articles | Volume 23, issue 12

https://doi.org/10.5194/bg-23-4057-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Special issue:

Mercury science to inform international policy: the Multi-Compartment...

https://doi.org/10.5194/bg-23-4057-2026

© Author(s) 2026. This work is distributed under
the Creative Commons Attribution 4.0 License.

Articles | Volume 23, issue 12

Research article

|

22 Jun 2026

Research article |

| 22 Jun 2026

DOM consumption and demethylation of MeHg as potential drivers of low MeHg in Mediterranean Sea sponges and benthic fish: a modeling perspective

David J. Amptmeijer, Ulrike Hanz, Corinna Schrum, and Johannes Bieser

Model code and software

Model_code_MERCY_ECOSMO-Sponge_Biaoccumulation David Amptmeijer https://doi.org/10.5281/zenodo.19880931

Short summary

Sponges have unusually low methylmercury (MeHg) and high inorganic mercury (iHg) bioaccumulation compared to other macrobenthos. This pattern has been attributed to MeHg demethylation by symbiotic bacteria. Our model demonstrates an alternative explanation that dissolved organic matter (DOM) consumption by sponges can increase iHg and decrease MeHg levels. Low MeHg in sponges at the food web base may further limit MeHg bioaccumulation in higher trophic levels.