Seasonal stratification is a widespread phenomenon of shelf seas which influences climate both regionally and through land sea heat exchange and globally through impacts on marine bioproduction and therefore the carbon cycle. This proposal seeks to investigate the long term (103 -104 years) dynamics of shelf sea stratification with the aim of defining the climatic role of physical and biogeochemical processes operating in extensive shallow seas during eustatic highstands. The proposal builds on Holocene modelling and observational pilot study from the Celtic sea by (1) an investigation of stable isotopic (oxygen, carbon) content of living benthic foraminifera from across the Celtic sea frontal region and (2) stable isotopic and faunal investigation of AMS 14C-dated Holocene cores underlying mixed, frontal and stratified localities in this area