Trace elements in relation to trophic ecology of long-distance migratory shorebirds and seabirds in West Africa

A study of trace elements in long-distance migratory shorebirds and seabirds in the Bijagós Archipelago, Guinea-Bissau, reveals that while exposure to most toxic elements is low, mercury (Hg) poses a potential high toxicity risk for at least one species, the Dunlin. The research analyzed blood samples from 16 species, finding positive relationships between selenium (Se), nickel (Ni), and trophic level (δ15N), as well as between habitat characteristics (δ13C) and Hg, iron (Fe), copper (Cu), manganese (Mn), and arsenic (As). Differences in trace element concentrations were also observed between the two trophic guilds, with seabirds showing higher levels of As, Pb, and Se compared to shorebirds. Despite high Cd and Pb concentrations previously reported in prey species, no toxicological risk was detected in birds for these elements. The study suggests that Hg warrants further monitoring due to its potential threat to coastal bird populations, particularly those experiencing local declines.

Correia, E., Granadeiro, J. P., Vale, C., & Catry, T. (2023). Trace elements in relation to trophic ecology of long-distance migratory shorebirds and seabirds in West Africa. Environmental Pollution, 316, 120674. https://doi.org/10.1016/j.envpol.2022.120674