HRZZ: Pollen in the Adriatic Sea: input dynamics, chemical characterization and effects on primary production (POLLMAR)
Principal investigator
Future climate change scenarios predict that pollen concentrations in the air will increase as pollination period lengthen due to increased atmospheric CO2 concentrations and higher temperatures. Land-sea interactions will become more intense, and because pollen contains a significant amount of organic nutrients, it is one of the allochthonous inputs to natural waters that may alter ecosystem dynamics. Although pollen input to freshwater systems (especially lakes) has been well studied, there is no information on effects of pollen input on phytoplankton production, a base of the marine trophic pyramid, in nearshore seawater. The phenomenon of yellow sea surface has been documented in recent years along the Adriatic coastal region from Kvarner, Šibenik, Split to Dubrovnik, and no one knows how long the pollen remains on the surface, how far it spreads at depth, and what consequences it leaves in the seawater. The interdisciplinary POLLMAR project will bring together experts in atmospheric chemistry, aerobiology, marine biogeochemistry, and oceanology to study, for the first time, the aerial pollen flux into the coastal areas of the central Adriatic Sea during the main pollination season (February to July). Laboratory experiments will investigate the dynamics of various pollen grain rupture under seawater and brackish water conditions, will identify and quantify the subpollen organic material leached, and will characterize the airborne pollutants that adsorb on the pollen grain surface. Finally, the microcosmos incubation experiment of collected pollen grains compared to dissolved organic subpollen matter will elucidate the effect of pollen input on marine primary production. This research is relevant to the Adriatic Sea as well as other oligotrophic coastal areas of the Mediterranean, which can respond rapidly to environmental stressors, especially occasional and excessive nutrient inputs from land and the atmosphere.