Coastal development can significantly impact nearby shorelines, raising concerns about erosion and sustainability. This study investigates the long-term effects of the Tangier Med port on the coastlines of Dalia and Ksar Sghir beaches in Morocco using remote sensing techniques and the Digital Shoreline Analysis System (DSAS). A multi-decadal approach analyzed shoreline changes for pre-construction (1988-2005) and post-construction (2004-2022) periods. Our findings reveal contrasting patterns. Ksar Sghir displayed accretion, due to port infrastructure disrupting natural sediment transport. Dalia beach exhibited a mixed response with ongoing erosion and localized accretion, influenced by the construction of a fishing port on the eastern side of the beach. To gain further insights into the future trajectory of these shorelines, we employed a Kalman filter model to predict shoreline positions for the year 2034 and 2044. These predictions highlight the potential for continued divergence between the beaches. Dalia beach faces potential infrastructure damage on the western side due to ongoing erosion, while the eastern side may require increased dredging to maintain fishing port access. Ksar Sghir beach, on the other hand, is projected to experience continued accretion with minimal anticipated negative impacts. This research offers valuable insights into the differential impacts of port development on adjacent coastlines. It highlights the importance of long-term monitoring and pre-construction data for understanding coastal interventions. Additionally, incorporating shoreline forecasting can aid in developing sustainable management strategies for both coastlines and port functionality.