The use of dinoflagellate cysts to separate human-induced from natural variability in the trophic state of the Po River discharge plume over the last two centuries

A determination key for modern dinoflagellate cysts

“…They have proven to be good tracers of marine primary productivity, reflecting changes in the trophic state of aquatic ecosystems, such as those due to human-induced pollution (Pospelova et al 2002;Krepakevich & Pospelova et al 2010;Satta et al 2010;Shin et al 2010;Zonneveld et al 2012). …”

Climate of the past 2500 years in the Gulf of Taranto, central Mediterranean Sea: A high-resolution climate reconstruction based on δ18O and δ13C of Globigerinoides ruber (white)

“…Chen et al, 2011;Cini Castagnoli et al, 1990;Grauel, 2012;Grauel et al, 2013;Taricco et al, 2009;Versteegh et al, 2007;Zonneveld et al, 2012). However, marine sediment records from the near coastal environment in the Gulf of Taranto have to be interpreted with caution because of seasonally highly variable hydrographic conditions and variable terrestrial inputs (Grauel et al, 2013).…”

Marine productivity leads organic matter preservation in sapropel S1: palynological evidence from a core east of the Nile River outflow

“…P. dalei is a cosmopolitan euryhaline species (Zonneveld et al, 2013). A recent study on eutrophication trends in the Mediterranean Sea reveals that production of cysts of P. dalei increases when upper water column phosphate concentrations increase (Zonneveld et al, 2012). The large peak in the AR of both species, recorded at the onset of sapropel deposition, therefore suggests a rapid shift, within a century, towards nutrient-rich, (seasonally) highly stratified surface waters.…”

“…Dinocysts are sensitive recorders of environmental conditions of the surface waters (Zonneveld et al, 2013) also in the area where our core was collected (e.g., Elshanawany et al, 2010). Therefore their fossil assemblages, concentrations and accumulation rates in marine sediments can be successfully employed to reconstruct palaeoenvironmental surface water conditions, providing information on nutrient availability, productivity, temperature, salinity, stratification, and oxygenation (e.g., Dale, 1996;De Vernal and Marret, 2007;Zonneveld et al, 2008Zonneveld et al, , 2012. Heterotrophic cysts are usually very abundant in high productivity zones (De Vernal and Marret, 2007, and references therein) and are therefore used to indicate trends in productivity.…”

“…The maximum in the dinocyst AR mainly results from peaks of L. machaerophorum, cysts of P. dalei and heterotrophic protoperidinioids. High occurrences of L. machaerophorum have been found in eutrophic areas under the influence of river plumes (Sangiorgi and Donders, 2004;Sangiorgi et al, 2005;Zonneveld et al, 2009), in areas where (seasonal) stratification occurs. P. dalei is a cosmopolitan euryhaline species (Zonneveld et al, 2013).…”