Because of the large influx of fresh water from rivers, especially from the Neva River (two-thirds of the total runoff), the gulf water has very low salinity – between 0.2 and 5.8 ‰ at the surface and 0.3–8.5 ‰ near the bottom.
Debido ao gran fluxo de auga doce dos ríos, especialmente do río Neva (dous terzos da escorrentía total), a auga do golfo ten unha salinidade moi baixa: entre 0,2 e 5,8 ‰ na superficie e 0,3-8,5 ‰ preto do fondo.