This document was created as part of the H2020 All Atlantic Ocean Sustainable, Profitable and Resilient Aquaculture (ASTRAL) project, to support Work Package 5 Climate – Ocean – Food. The study aimed to conduct a literature review towards the identification of the biotic and abiotic conditions favouring the development of harmful algal blooms (HABs) for selected case study sites, commenting both on future HAB-related risks associated with climate change and the recommended HAB-related variables and parameters to be monitored. Although the ASTRAL project focuses primarily on integrated multi-trophic aquaculture (IMTA) production, this document provides an informative overview with a much broader scope. The document is split into several sections including; An extensive literature study on abiotic and biotic factors affecting HAB were performed; Several factors favouring HABs have been identified with stratification and eutrophication playing an important role; A list was compiled with recommendations for environmental monitoring which was supplemented with case studies on HAB occurrence at the various IMTA labs; Suitability of earth observation data at a regional scale was assessed by a literature study and a case study at IMTA lab South Africa; Vulnerability of IMTA labs to climate change and an in-depth case study of the potential area for the IMTA lab in Argentina was conducted. The results obtained will be essential to i) boost research and innovation for new and cost-effective monitoring in real-time mode technologies, in line with the uptake, mode of action and consequences, and ii) propose optimal monitoring recommendations to minimise risks related to climate change and environmental stressors of ASTRAL IMTA-systems.