Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Review
. 2023 Oct;32(8):994-1009.
doi: 10.1007/s10646-023-02679-y. Epub 2023 Jun 16.

Are tunas relevant bioindicators of mercury concentrations in the global ocean?

Anaïs Médieu  1 , Anne Lorrain  2 , David Point  3
Affiliations
Review

Are tunas relevant bioindicators of mercury concentrations in the global ocean?

Anaïs Médieu et al. Ecotoxicology. 2023 Oct.

Abstract

Humans are exposed to toxic methylmercury mainly by consuming marine fish. The Minamata Convention aims at reducing anthropogenic mercury releases to protect human and ecosystem health, employing monitoring programs to meet its objectives. Tunas are suspected to be sentinels of mercury exposure in the ocean, though not evidenced yet. Here, we conducted a literature review of mercury concentrations in tropical tunas (bigeye, yellowfin, and skipjack) and albacore, the four most exploited tunas worldwide. Strong spatial patterns of tuna mercury concentrations were shown, mainly explained by fish size, and methylmercury bioavailability in marine food web, suggesting that tunas reflect spatial trends of mercury exposure in their ecosystem. The few mercury long-term trends in tunas were contrasted and sometimes disconnected to estimated regional changes in atmospheric emissions and deposition, highlighting potential confounding effects of legacy mercury, and complex reactions governing the fate of mercury in the ocean. Inter-species differences of tuna mercury concentrations associated with their distinct ecology suggest that tropical tunas and albacore could be used complementarily to assess the vertical and horizontal variability of methylmercury in the ocean. Overall, this review elevates tunas as relevant bioindicators for the Minamata Convention, and calls for large-scale and continuous mercury measurements within the international community. We provide guidelines for tuna sample collection, preparation, analyses and data standardization with recommended transdisciplinary approaches to explore tuna mercury content in parallel with observation abiotic data, and biogeochemical model outputs. Such global and transdisciplinary biomonitoring is essential to explore the complex mechanisms of the marine methylmercury cycle.

Keywords: Biomonitoring; Methylmercury; Minamata Convention; Spatial gradients; Standardized monitoring guidelines; Temporal trends.

PubMed Disclaimer

References

    1. AMAP, 2021. AMAP Assessment 2021: Mercury in the Arctic. Arctic Monitoring and Assessment (AMAP). Tromso, Norway
    1. Angot H, Hoffman N, Giang A, Thackray CP, Hendricks AN, Urban NR, Selin NE (2018) Global and Local Impacts of Delayed Mercury Mitigation Efforts. Environ Sci Technol 52:12968–12977. https://doi.org/10.1021/acs.est.8b04542 - DOI
    1. Axelrad DA, Bellinger DC, Ryan LM, Woodruff TJ (2007) Dose–Response relationship of prenatal mercury exposure and IQ: An integrative analysis of epidemiologic data. Environ Health Perspectives 115:609–615. https://doi.org/10.1289/ehp.9303 - DOI
    1. Barbosa RV, Point D, Médieu A, Allain V, Gillikin DP, Couturier LIE, Munaron J-M, Roupsard F, Lorrain A (2022) Mercury concentrations in tuna blood and muscle mirror seawater methylmercury in the Western and Central Pacific Ocean. Marine Pollut Bull 180:113801. https://doi.org/10.1016/j.marpolbul.2022.113801 - DOI
    1. Bearhop S, Ruxton GD, Furness RW (2000) Dynamics of mercury in blood and feathers of great skuas. Environ Toxicol Chem 19:1638–1643. https://doi.org/10.1002/etc.5620190622 - DOI

LinkOut - more resources