Freshwater inputs

Tim Jickells,
Laboratory for Global Marine and Atmospheric Chemistry
University of East Anglia
Norwich UK NR4 7TJ

T.Jickells@uea.ac.uk

I will briefly consider the nature of groundwater, atmospheric and riverine inputs to marine systems noting temporal and spatial variability in magnitude and nature. The talk will mainly focus on the role of nutrient inputs, but will also consider briefly other mechanisms by which freshwater inputs impact phytoplankton growth. The talk will attempt to address the question of whether inputs as measured at a monitoring site can be extrapolated to the key areas relevant to phytoplankton growth.

Time-series observations of phytoplankton community structure are lacking for the Irish Sea making it difficult to evaluate the effects of enrichment. A recent study of Liverpool Bay and Irish coastal waters documented elevated spring production and biomass in the Bay but only small differences in species composition were apparent between the two sites. In offshore western Irish Sea waters, diatom and flagellate dominance of the spring bloom switches from year to year and may indicate that the western Irish Sea is undergoing a transition.