Quantifying Spatio-temporal risk of Harmful Algal Blooms and their impacts on bivalve shellfish mariculture using a data-driven modelling approach

•Low biomass Dinophysis blooms impact shellfish aquaculture in Northern Europe.•Impacts were modelled using decadal HAB monitoring data for the UK and France.•Generalised Additive Models capture seasonal change and spatiotemporal interactions.•Dinophysis toxin levels in shellfish were predicted for locations with unseen data.•Model framework indicates long-term HAB risk for shellfish aquaculture planning.