A new hypothesis for the Holocene appearance of coccolithophores in the Black Sea

Abstract

A recent accelerator mass spectrometer (AMS) radiocarbon study of Black Sea Holocene sediments has resolved a long-standing chronology controversy involving radioisotope and varve- counting methodologies. The revised chronology combined with model results of the salinity evolution of the Black Sea since the last glacial maximum does not support the hypothesis of a salinity-controlled Holocene invasion of the Black Sea by coccolithophores, a planktonic golden-brown unicellular marine algae. Rather, evidence presented here is used to suggest these organisms were inadvertently transported from the Mediterranean Sea by sailing vessels during the Greek exploration and colonization of the Black Sea in the seventh and eighth centuries BC. As such this may be one of the earliest examples of anthropogenic transport of marine organisms between ocean basins, and a good example of the difficulties inherent in distinguishing natural from anthropogenic effects when studying Holocene biological systems.