Abstract
useful tool in (paleo)climatology since it captures inter- and
intra-annual variability in environmental conditions. Trace
element and stable isotope analysis with improved sampling
resolution now allows in situ determination of the composition of mollusk shell volumes precipitated at daily to
sub-daily time intervals. Here, we discuss hourly resolved
Mg /Ca, Mn /Ca, Sr /Ca, and Ba /Ca profiles measured by
laser ablation inductively coupled plasma – mass spectrometry (ICP-MS) through shells of the photosymbiotic giant
clams (Tridacna maxima, T. squamosa, and T. squamosina)
and the non-photosymbiotic scallop Pecten maximus. Precise sclerochronological age models and spectral analysis allowed us to extract daily and tidal rhythms in the trace element composition of these shells. We find weak but statistically significant expressions of these periods and conclude that this cyclicity explains less than 10 % of the subannual variance in trace element profiles. Tidal and diurnal rhythms explain variability of, at most, 0.2 mmol mol−1
(∼ 10 % of mean value) in Mg /Ca and Sr /Ca, while ultradian Mn /Ca and Ba / Ca cyclicity has a median amplitude
of less than 2 µmol mol−1 mol mol−1
(∼ 40 % and 80 % of
the mean of Mn /Ca and Ba /Ca, respectively). Daily periodicity in Sr /Ca and Ba /Ca is stronger in Tridacna than
in Pecten, with Pecten showing stronger tidal periodicity.
One T. squamosa specimen which grew under a sunshade
exhibits among the strongest diurnal cyclicity. Daily cycles
in the trace element composition of giant clams are therefore unlikely to be driven by variations in direct insolation
but rather reflect an inherent biological rhythmic process affecting element incorporation. Finally, the large amount of
short-term trace element variability unexplained by tidal and
daily rhythms highlights the dominance of aperiodic processes in mollusk physiology and/or environmental conditions over shell composition at the sub-daily scale. Future
studies should aim to investigate whether this remaining variability in shell chemistry reliably records weather patterns or
circulation changes in the animals’ environment.
| Original language | English |
|---|---|
| Pages (from-to) | 3027-3052 |
| Number of pages | 26 |
| Journal | Biogeosciences |
| Volume | 20 |
| Issue number | 14 |
| DOIs | |
| Publication status | Published - 28 Jul 2023 |
Bibliographical note
Publisher Copyright:© Copyright:
Funding
The authors would like to thank Leonard Bik for his help with the sample preparation and Maarten Zeilmans for his help with the high-resolution imaging of the samples at Utrecht University. This study is part of the UNBIAS project, jointly funded by the Flemish Research Foundation (FWO; grant no. 12ZB220N) post-doctoral fellowship (Niels J. de Winter) and a Marie Skłodowska-Curie Actions (MSCA) Individual Fellowship (grant nos. H2020-MSCA-IF-2018, 843011 – UNBIAS; awarded to Niels J. de Winter). Gert-Jan Reichart and Lennart de Nooijer acknowledge funding from the Netherlands Earth System Science Center (NESSC; grant no. 024.002.001) from the Dutch Ministry for Education, Culture and Science (gravitation grant no. NWO 024.002.001). Bernd R. Schöne acknowledges funding from the Deutsche Forschungsgemeinschaft (DFG; grant nos. SCHO 793/21 (HIPPO) and SCHO 793/23). Julien Thébault was funded by the French National Research Agency (ANR; grant no. ANR-18-CE92-0036-01) awarded within the framework of the French-German collaborative project HIPPO (HIgh-resolution Primary Production multiprOxy archives). This research has been supported by the European Commission, Horizon 2020 Framework Programme (UNBIAS (grant nos. H2020-MSCA-IF-2018, 843011)); the Fonds Wetenschappelijk Onderzoek (grant no. 12ZB220N); the Aard- en Levenswetenschappen, Nederlandse Organisatie voor Wetenschappelijk Onderzoek (grant no. 024.002.001); the Deutsche Forschungsgemeinschaft (grant nos. SCHO/793/21 and SCHO 793/23); and the Agence Nationale de la Recherche (grant no. ANR-18-CE92-0036-01).
| Funders | Funder number |
|---|---|
| Aard- en Levenswetenschappen | |
| Dutch Ministry for Education, Culture and Science | NWO 024.002.001 |
| European Commission, Horizon 2020 Framework Programme | |
| UNBIAS | |
| H2020 Marie Skłodowska-Curie Actions | H2020-MSCA-IF-2018, 843011 |
| Deutsche Forschungsgemeinschaft | SCHO 793/21, SCHO 793/23 |
| Agence Nationale de la Recherche | ANR-18-CE92-0036-01 |
| Fonds Wetenschappelijk Onderzoek | 12ZB220N |
| Nederlandse Organisatie voor Wetenschappelijk Onderzoek | 024.002.001 |
| Netherlands Earth System Science Centre |