Taxonomic units, civilization, volcanism: Their influence on the chemical composition of ostracod carapaces (Kagoshima Bay, Kyushu Island, Japan)
Résumé
To test the influence of both civilization and volcanism on the chemical composition of ostracod carapaces, 32 wellpreserved valves from Kagoshima Bay (Kyushu Island, South Japan) were analysed by means of spark source mass spectrometry. In Kagoshima Bay, the extent of pollution corresponds to human activities. Kagoshima Bay is also an area of important volcanic activity: emissions from Sakurajima volcano are very frequent. The species analysed were Argilloecia hanaii , Callistocythere undulatifacialis , Pontocythere subjaponica and Loxoconcha tosaensis . Twenty-three chemical elements were detected. Among them, 11 were always above the limit of detection: Al, B, Cl, F, Fe, K, Na, P, S, Si and Zn. The correlation between Zn and Fe was characteristic of the volcanic environment. Two discriminant analyses were performed using either the location area or the species as grouping variables. An association between Zn and S is possible; it could be related to volcanic activity. The chemical composition of carapaces is ascribed to taxonomic units rather than the environment.