Abstract
Planktonic foraminifera (PF) life cycles are highly sensitive to marine conditions, which are evolving rapidly due to anthropogenic climate change. Even though PF shells in the sedimentary record serve as prominent proxies of past ocean conditions, very little is still known about their life cycles, particularly in oligotrophic environments. Here, we present a full annual record of PF fluxes (> 63 µm) from the oligotrophic Gulf of Aqaba, northern Red Sea, sampled at daily timescales during 2015–2016 using an automated time-series sediment trap. These results are coupled with daily surface chlorophyll-a concentrations, sea surface temperatures (SSTs), particulate organic carbon and bulk fluxes, together with monthly resolved vertical profiles of chlorophyll-a, temperatures and nutrient concentrations. The annual cycle of PF fluxes is controlled by SST changes that drive water column mixing and changes in food availability. PF species flux patterns and succession dynamics vary throughout the year, displaying large variability on previously undocumented daily-weekly timescales, and are not synchronized with lunar periodicity. On daily timescales, spring blooms show a complex structure and interplay between SSTs, chlorophyll-a surface concentrations and PF fluxes. These events deliver about a third of the total annual PF flux over a period of several weeks.
| Original language | English |
|---|---|
| Article number | 17456 |
| Journal | Scientific Reports |
| Volume | 10 |
| Issue number | 1 |
| DOIs | |
| State | Published - 15 Oct 2020 |
| Externally published | Yes |
Bibliographical note
Publisher Copyright:© 2020, The Author(s).
Funding
We thank B. Yarden for assistance in sample handling and acknowledge the efforts and dedication of the IUI marine crew: S. Baruch, I. Daskal, O. Ben-Shaprut, E. Sestieri, M. Ohavia, S. Isaacs and A. Rivlin. Y. Shaked and the National Monitoring Program are thanked for their support and sharing results. Comments and suggestions by Lennart de Nooijer and another anonymous reviewer helped greatly improve this manuscript and we further thank M. Frada and Y. Lindemann for fruitful discussions. This work was supported by scholarships from the Advanced School for Environmental Studies, HUJI, and the Mediterranean Sea Research Center of Israel (to NC), the Schulich Ocean Studies Centre Initiative Grant #3 (to SSK and AT) and Israel Science Foundation Grants #927/15 and 834/19 (to AT).
| Funders | Funder number |
|---|---|
| Mediterranean Sea Research Center of Israel | |
| Schulich Ocean Studies Centre Initiative | |
| Israel Science Foundation | 834/19, 927/15 |
