Obiettivo
This project investigates factors influencing the patterns of phytoplankton dominance found in European coastal waters. The ultimate aim is to provide a scientific base for the hypothesis that phytoplankton classes occupy different ecological niches defined by the degree of stratification and either nutrient availability or water column clarity.
Factors which affect phytoplankton class dominance were studied in coastal waters of Ireland and Spain. Both physical (advection) and biological (growth) phenomena were found responsible in controlling dominance of either diatoms or dinoflagellates. Within rias at both sites, water exchange occurring as a consequence of upwelling or other physical events was the key driving variable affecting class dominance. The effect was either simply exchange of communities or, it is argued, provision of a range of dilution rates down the water column during efflux or influx events thereby biasing community structure to faster growing species in the surface layers and slower growing ones in the pycnocline.
Research will concentrate on sites in SW Ireland and NW Spain. Our approach will combine field studies of phytoplankton populations (their location, biomass and in-situ growth rates), together with a close monitoring of the chemical and physical environment. The latter will be facilitated by the use of moored instrumentation, which will enable us to monitor the effects of transient changes.
By increasing our understanding of environmental influences on populations and processes at the base of the food chain, the project will improve our ability to understand and model coastal ecosystems and provide an insight into the physiological mechanisms responsible for exceptional blooms of dinoflagellates, sometimes economically damaging, which periodically occur in European waters.