Keskkonnamoju hindamise eesmärk on selgitada, hinnata ja kirjeldada Naissaare liivamaardla mäeeraldistest Naissaare 1 ja Naissaare 2 kaevandamise eeldatavat moju keskkonnale, analüüsida selle moju vältimise voi leevendamise voimalusi. AS Tallinna Sadam taotleb Naissaare ja Littegrundi madala piirkonnas madalmeres kaevandusluba eesmärgiga kaevandada liiva Muuga sadamas ehitustööde tarbeks. Liiva kasutatakse täitematerjalina uute kaide rajamisel. Ehitustöödeks vajalik liiva maht on 5 miljonit m3. Maardla asub Muuga sadamale suhteliselt lähedal, mis holbustab selle transporti ja kasutamist. Liiva transport mööda merd on logistiliselt sadama ehitusele koige otstarbekam ja samas ka keskkonnale väiksema mojuga kui liiva vedamine maismaalt.
Mining from the Naissaar 1 and Naissaar 2 mining claims is accompanied by the following environmental impacts: Formation of suspended matter generates negative impact of little importance on water quality. The impact of suspended matter reaches approximately to a distance of 1 km from area of extraction. The excavation on the seafloor formed in the result of sand extraction generates negative impact of little importance on wave activity, currents and sediment transport. Suspended matter creates negative impact of little importance on phytobenthos. Extraction creates negative impact on zoobenthos. Removal of zoobenthos causes negative impact of little importance on the fish via the food chain. To mitigate the negative impact of suspended matter we recommend leaving ca 4-hour break between the pumping of sand during which the suspended matter can deposit. This means using one trailing suction hopper dredger at a time. In such case the required sedimentation period will form on the account of delivering the sand and pumping it out. During this time interval the generated suspended matter will deposit. The results of monitoring during sand extraction from Naissaar and Prangli deposits have shown this. To reduce the impact on wave activity, currents and sediment transport we recommend to preserve the sand planned to be left in the slopes of the excavation. Thus, the slopes of the excavation become shelving and the deposits are more intensively carried into the excavation. To mitigate the negative impact on phytobenthos we recommend leaving ca 4-hour break between the pumping of sand during which the suspended matter can deposit. To mitigate the impact on zoobenthos we recommend extracting the sand during a single stage, so the communities of zoobenthos will start recovering in this area. To avoid the impact on ichthyofauna we suggest not to extract sand from Hiiumadal deposit from Aprile to July. Thus the larvas will not be damaged. To mitigate the impact on ichthyofauna we recommend to extract the sand during a single stage, so the communities of zoobenthos will start recovering in this area