The present study evaluates the influence of industrialization on suspended particulate matter (SPM) dynamics along the northern coast of Rio de Janeiro, focusing specifically on the Açu Port Industrial Complex (APIC). A 20-year MODIS-Aqua (1 km) dataset (2002–2022) was processed using the OC-SMART atmospheric correction. For SPM estimation, a retrieval approach for coastal turbid waters that integrates two optimized bio-optical algorithms based on Optical Water Types (OWTs) was developed. The validity of this approach was substantiated through the utilization of the GLORIA in situ dataset and satellite matchups, which demonstrated its robust performance across a range of turbidity conditions. Its main innovation lies in the OWT-based fusion of two optimized SPM models, enabling robust retrievals across diverse coastal optical conditions. Statistical analyses based on Census X11 decomposition and the Seasonal Mann–Kendall test revealed strong spatial and temporal variability, with SPM concentrations increasing by up to 60% near the APIC during the study period, coinciding with dredging, port expansion, and sediment disposal. These findings indicate a pronounced anthropogenic signal, while spatial and temporal correlation analyses demonstrated that sediment dispersion is consistently directed northward, primarily controlled by currents and wind forcing. The results indicate that industrial activities augment the supply of sediments, while natural hydrodynamic processes govern their dispersion and transport, emphasizing the impact of human pressures and physical drivers on coastal sediments.

Coastal ecosystems play essential ecological, social, and economic roles at the land-ocean interface and are highly sensitive to environmental changes, whether natural or human-induced. Monitoring these regions is crucial for developing sustainable, ecosystem-based environmental policies (UNESCO-IOC). Brazil, with approximately 8,000 kilometers of tropical and subtropical coastline, hosts diverse coastal and marine ecosystems. However, these areas face significant pressures, including climate change, urban expansion, intensive agriculture, and deforestation. Despite their importance, Brazil, like many coastal regions, lacks extensive, long-term in situ data to assess how these pressures impact biogeochemical quality. Ocean color remote sensing helps fill this data gap by continuously providing key biogeochemical variables—such as phytoplankton biomass, particulate and dissolved matter, and associated organic carbon stocks—for over 25 years. This study demonstrates how optimized ocean color data can offer a comprehensive view of coastal ecosystems' responses to human pressures on both land and ocean. Specifically, MODIS ocean color time series have been analyzed to identify trends in the biogeochemical properties of Brazilian coastal and shelf waters, including estuaries, bays, and major lagoons, over the past two decades (COCOBRAZ ANR FAPESP project). This work illustrates how ocean color data can be a major source of information for supporting the preservation and management of coastal ecosystems.