Planktonic foraminifera as bio‐indicators for monitoring the climatic changes that have occurred over the past 2000 years in the southeastern Tyrrhenian Sea

Abstract

A high-resolution integrated study has been performed in a super-expanded marine record (sedimentation rate spanning from 11 cm/100 years to 20 cm/100 years) from the continental shelf area of the southeastern Tyrrhenian Sea. Planktonic foraminiferal distribution illustrates 6 major environmental changes during the past 2000 years: (i) the Roman Period-Dark Age transition (from herbivorous-opportunistic to carnivorous species); (ii) the Dark Age-MCA transition (from carnivorous to herbivorous-opportunistic species); (iii) the Medieval Classic Anomaly-Little Ice Age transition (a further and definitive change from carnivorous to herbivorous-opportunistic species); (iv) the period during the Maunder event between approximately 1720 AD and 1740 AD (turnover from the carnivorous planktonic foraminifer Globigerinodes ruber to the herbivorous-opportunistic planktonic foraminifer Turborotalita quinqueloba); (v) the Industrial Period (dominance of herbivorous-opportunistic planktonic foraminifera); and (vi) the Modern Warm Period at approximately 1940 AD (the last turnover in favor of herbivorous-opportunistic planktonic foraminifers, associated with an increase in benthic foraminifera). Our studies lead us to link this latter feature to an anthropogenic impact associated with the damming of Sele River (Salerno Gulf) at 1934 AD, which induced a change in the sediment input with a strong decrease in coarse-grained fraction and a probable alteration in nutrient supply. The δ(18) OG. ruber record of the past 2000 years shows the alternation of warm/wet and cold/dry events related to the Roman Period, the Dark Age, the Medieval Classic Anomaly, the Little Ice Age, the Industrial Period and the Modern Warm Period. The 5 evident δ(18) OG. ruber oscillations (between approximately 1325 AD and 1940 AD) coincide with the 5 minima in the solar activity record (Wolf, Spörer, Maunder, Dalton and Damon events).

Sea Surface Temperatures and Paleoenvironmental Variability in the Central Mediterranean During Historical Times Reconstructed Using Planktonic Foraminifera

“…The planktonic foraminifera assemblages at St 342 and 407 are compatible with data of the top ecobiozone from central‐western Mediterranean sites, highlighted by the dominance of G. ruber , G. bulloides and G. inflata and the low abundance of G. sacculifer and N. incompta (Capotondi et al, ; Lirer et al, ; Margaritelli et al, ; Sbaffi et al, ; Sprovieri et al, ; Vallefuoco et al, ). Moreover, some of the peaks that characterize Tyrrhenian Sea and Menorca Basin historical records (Lirer et al, ; Margaritelli et al, ; Margaritelli et al, ) also occur in the Sicily Channel, such as the G. truncatulinoides peak in coincidence of the Maunder minimum and the G. ruber peak at ~1950 CE (Figure ). The latter is only visible in St 342 (Figure ), highlighting local variability even in sedimentary records that are a few kilometers far each other.…”

“…2013; Margaritelli et al, 2016;Sbaffi et al, 2001;Sprovieri et al, 2003;Vallefuoco et al, 2012). Moreover, some of the peaks that characterize Tyrrhenian Sea and Menorca Basin historical records (Lirer et al, 2014;Margaritelli et al, 2016;Margaritelli et al, 2018) also occur in the Sicily Channel, such as the G. truncatulinoides peak in coincidence of the Maunder minimum and the G. ruber peak at~1950 CE (Figure 2). The latter is only visible in St 342 (Figure 2), highlighting local variability even in sedimentary records that are a few kilometers far each other.…”

Paleontology and evolution‐part II

“…Conversely, an example of the evolution of marine communities over a very short time scale is provided by Lirer et al (2014), who analyze the climatic changes that occurred during the past 2000 years in a highresolution, integrated study of a super-expanded marine record from the southeastern Tyrrhenian Sea. These authors identify 5 major environmental changes, marked by changes in the relative frequency of herbivorous versus carnivorous and opportunistic versus generalist planktonic foraminifera.…”

Paleontology and evolution–part I

“…The evolution of marine communities can be analyzed under 2 perspectives: the deep time dimension of the paleoecological modifications, as that involved by the GOBE, and the changes of their structure over short time scale. This approach was followed by Lirer et al (2014) to monitor the climatic changes that occurred during the last 2000 years. With a high-resolution, integrated study of a super-expanded marine record from the SE Tyrrhenian Sea, the authors identify 5 major environmental changes (transition from the Roman period to the Dark Age, the Dark Age to the Medieval Classic Anomaly, the Medieval Classic Anomaly to the Little Ice Age, and the Maunder event and the period at ca.…”

“…The evolution of marine communities can be analyzed under 2 perspectives: the deep time dimension of the paleoecological modifications, as that involved by the GOBE, and the changes of their structure over short time scale. This approach was followed by Lirer et al (2014) This issue also includes a number of papers devoted to taxa that lived on islands, from very large (Australia, Worthy et al 2014) to small ones (Mallorca, Bover et al 2014). Islands have long been recognized as laboratories for biological studies, as well as a precious source to the understanding of time and mode of Evolution and of the processes that determine global biotic diversity.…”