Reconstruction of salinity in the Holocene Black Sea has been an ongoing debate over the past four decades. Here we calibrate summer surface water salinity in the Black Sea, Sea of Azov and Caspian Sea with the process length of the dinoflagellate cyst Lingulodinium machaerophorum. We then apply this calibration to make a regional reconstruction of paleosalinity in the Black Sea, calculated by averaging out process length variation observed at four core sites from the Black Sea with high sedimentation rates and dated by multiple mollusk shell ages. Results show a very gradual change of salinity from ∼14 ± 0.91 psu around 9.9 cal ka BP to a minimum ∼12.3 ± 0.91 psu around 8.5 cal ka BP, reaching current salinities of ∼17.1 ± 0.91 psu around 4.1 cal ka BP. The resolution of our sampling is about 250 years, and it fails to reveal a catastrophic salinization event at ∼9.14 cal ka BP advocated by other researchers. The dinoflagellate cyst salinity-proxy does not record large Holocene salinity fluctuations, and after early Holocene freshening, it shows correspondence to the regional sea-level curve of Brückner et al. (2010) derived from Balabanov (2007).
Bibliographical noteFunding Information:
Kenneth N. Mertens is a Postdoctoral scholar of FWO Belgium. This research was conducted by the lead author at Nagasaki University, Japan thanks to a JSPS fellowship. Financial support to Thomas J. Verleye was provided by the Institute for the Encouragement of Innovation through Science and Technology in Flanders (IWT). Petra Mudie, Ali Aksu, Richard Hiscott and Vera Pospelova are grateful for financial support from the Natural Sciences and Engineering Research Council of Canada (NSERC). Lee Bradley and Fabienne Marret thank the Leverhulme Trust for financial support. The officers and crew of RV Koca Piri Reis are thanked for facilitating the collection of the MAR cores in 2002 and 2005. Petra Mudie, Lee Bradley and Fabienne Marret acknowledge the help of Helen Gillespie, Memorial University of Newfoundland, in processing of samples from the MAR cores. Anna Linegar helped calibrate raw 14 C dates. Dr. Marcel van der Meer (NIOZ) is thanked for providing samples of boxcore BC53. Jennifer Cranshaw is acknowledged for clarifying the amount of core-top loss for MAR05-13P, and its correlation with MAR05-4G. We are grateful to Dr Igor Bondarev, National Academy of Science of Ukraine, Sevastopol, for diving to sample for living dinoflagellate cysts on the NW Black Sea shelf during INQUA 501 field trip 2. We thank Dennis Dunn, Adam Willingham, and Carrie Wolfe (the Southern California Marine Institute) for their assistance in sediment sampling in San Pedro Harbor, California. Neslihan Balkis is thanked for help with obtaining salinity data and Helmut Brückner for communications on sea-level variations in the Black Sea. The comments of wo anonymous reviewers were appreciated.
- Black Sea
- Caspian Sea
- Lingulodinium machaerophorum
- Marmara Sea
- RDNA analysis
- Sea of Azov