As development of offshore aquaculture projects increases, daily monitoring of net pens becomes increasingly difficult and the need for remotely sensed monitoring tools becomes more of a priority. Increased dissolved nutrients resulting from offshore aquaculture pens could have an impact on phytoplankton composition and the potential to trigger the onset of harmful algal blooms (HABs) . The impact of these blooms on the aquaculture industry amounts to approximately $8 billion/year globally due to mass mortalities in finfish, shellfish harvesting bans due to accumulation of phycotoxins, and human health costs. Currently, there are multiple commercial, academic, and government agencies working on remote sensing technologies to monitor offshore aquaculture facilities. This technology-based discussion aims to review current remote sensing technologies specifically used to monitor HABs and their applications to the offshore aquaculture industry . This review highlights current remote sensing HAB monito ring technologies along with their successes, limitations, knowledge gaps, and research needs. These technologies will be essential tools for early detection, tracking, and forecasting of HABs to improve fish health and operational efficiency of offshore aquaculture facilities.