Over the past decades, the use of remote sensing as tool for marine aquaculture has become increasingly popular. Remote sensing has a remarkable advantage that gives it a unique potential: low-cost acquisition of continuous data across medium-large spatiotemporal scales. Moreover, with the expected rapid advances in technology and increase in Earth observation satellites, the role of remote sensing in marine aquaculture is only expected to grow. One of the main applications of remote sensing for ocean observation is the monitoring of marine phytoplankton - ocean colour remote sensing (OCRS). Phytoplankton, photosynthetic microorganisms, is considered as one of the most important biological components of the marine ecosystem and is widely regarded as a good indicator of changes. Several parameters can be used to evaluate phytoplankton using OCRS. Chlorophyll a (chl a) is the most common as it allows for the monitoring of changes in the biomass in regions of interest. Among the main applications of using chl a in is the identification of productive areas for the establishment or redefinition of aquaculture sites or the monitoring of harmful algal blooms. Chl a can also be used to study phytoplankton bloom phenology, i.e., the timings of the blooms and its main properties. Phenology enables the identification of the blooms, as well as analysing irregularities in the annual and seasonal phytoplankton cycles for a given region. The main goal of this work is to test and evaluate the potential of OCRS for marine offshore aquaculture, using the Western Iberian Coast (WIC; SW Europe) as a case study. This will be done by performing four tasks: 1) assess the mean climatological and seasonal cycles of chl a; 2) evaluate the phenology of phytoplankton blooms; 3) definition of preferential regions for aquaculture using a mixture of phenological, biological and physical indices; and 4) in-depth study of phenology for a given potential aquaculture site. Results will be presented (see figure 1 for examples of preliminary results) and are expected to contribute to establishing OCRS as a gamechanger for managing marine offshore aquaculture.