The most significant environmental impacts are related to construction activity in Muuga Harbour, Saaremaa Harbour and Paldiski South Harbour.

Marine environment monitoring was also performed in the Naissaar sand deposit in connection with extraction of sand for the expansion of the eastern part of Muuga Harbour. The monitoring was performed by experts from the Marine Systems Institute at the Tallinn University of Technology, the University of Tartu’s Estonian Marine Institute and the Estonian Ornithological Society.

Marine environment monitoring has been conducted at Muuga Harbour since 1995. The objective of the monitoring is to assess the impact arising from the port’s activities and the impact of filling and dredging operations in years past on the zoobenthos, flora, fish and coastal processes in the near vicinity.

In connection with the construction of Saaremaa Harbour, monitoring of the marine environment and bird life was performed after construction. The main objective of the monitoring is to assess the impact arising from the port’s activities on the environment in the Küdema Bay, which is a bird area of international importance, and the Natura 2000 Küdema Bay special area of conservation. Experts concluded that the impact of Saaremaa Port on the birds and other mammals, plant communities and coastal processes is practically non-existent. Thanks to the serious attitude from the Port of Tallinn in regard to compliance with the monitoring obligation, the waters of Küdema Bay are one of the most closely studied seabird areas in Estonia.