Impact of heavy metals (Cu, Fe, Pb, Zn) on carbon and nitrogen uptake of the diatom-bearing benthic foraminifera Heterostegina depressa

Author(s): Mario Bubl, Petra Heinz, Wolfgang Wanek, Michael Schagerl, Thilo Hofmann, Michael Lintner
Abstract: Foraminifera are protists primarily living in benthic marine and estuarine environments. We studied uptake of inorganic carbon (C) and nitrogen (N) of the photosymbiont-bearing benthic coral reef foraminifera Heterostegina depressa in the presence of heavy metals. Incubation experiments were accomplished with artificial seawater enriched with copper, iron, lead and zinc at two different concentration levels (10 and 100 fold enriched in contrast to the usual culture medium). Additionally, isotopically labelled ¹³C-sodium bicarbonate and ¹⁵N-ammonium chloride were added to trace their assimilation over time (1 d, 3 d, 5 d, 7 d). Pulse-amplified modulated fluorescence measurements were performed to measure the potential impacts of heavy metals on chlorophyll fluorescence of the photosymbiont. Increased levels of copper (430.5 μg Cu/l) exhibited the greatest toxicity, while for low levels no effect on the overall metabolism of the foraminifera and the fluorescence activity of the photosymbiont could be detected. Iron (III) increased the symbiont activity, independent of concentration applied (44.5 and 513.3 μg Fe/l), which indicates Fe-limitation of the algal symbiont. Lead enrichment showed no detectable effect even at high concentration. Low concentrations of zinc (35.1 μg Zn/l) promoted the metabolism of the foraminifera, while high concentrations (598.4 μg Zn/l) were toxic. At low levels, two metals (Fe and Zn) promoted symbiont activity, at high levels, iron still boosted photosynthesis, but Zn and Cu had a negative impact on the obligatory photosynthetic symbionts.
Organisation(s): Department of Palaeontology, Department of Microbiology and Ecosystem Science, Functional and Evolutionary Ecology, Department of Environmental Geosciences
External organisation(s): Polish Academy of Sciences (PAS)
Journal: Heliyon
Volume: 10
No. of pages: 7
ISSN: 2405-8440
DOI: https://doi.org/10.1016/j.heliyon.2024.e27229
Publication date: 03-2024
Peer reviewed: Yes
Austrian Fields of Science 2012: 106026 Ecosystem research, 105906 Environmental geosciences
Keywords
ASJC Scopus subject areas: General
Sustainable Development Goals: SDG 14 - Life Below Water
Portal url: https://ucrisportal.univie.ac.at/en/publications/fdf01dd2-9d1f-425b-af56-2dabaf4e120e

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