This dataset was created for niche modelling (GBM model) with weekly maximum HAB species cell counts per ID (this ID matching Climate_run_corr.rds and Projection_corr.rds) and combined with Climate_run_corr.rds. This 20 year dataset contains data on weekly maximum cell abundance of harmful taxa, namely, Dinophysis acuta, Dinophysis acuminata, total Dinophysis spp., “Pseudo-nitzschia delicatissima” complex, “Pseudo-nitzschia seriata” complex, total Pseudo-nitzschia spp., Karenia mikimotoi and total Karenia spp. and environmental data, Sea Surface Temperature, Near Bottom Temperature, Sea Surface Salinity, Near Bottom Salinity and Potential Envergy Defecit in the period from 1st January 1997 to 31st December 2016; this time period matches the hindcast numerical model output (20 year hindcast [1997-2016], SW_IRL_ROMS_Hindcast). None Suggested Citation: Yamanaka, Tsuyuko; Fabri-Ruiz, Salomé; Nagy, Hazem; Pereiro, Diego; Cusack, Caroline; Nolan, Glenn; Dabrowski, Tomasz; Clarke, Dave. (2021) Harmful Algal Blooms (HABs) weekly maximum and environmental dataset 1997-2016 North East Atlantic Ocean. Marine Institute, Ireland. doi:10/fvsf.