How is it that the lakes that flow into the ocean aren’t salty
They are formed from rainwater that has evaporated from the sea. The salt gets left behind as the water turns to vapour, just like distillation. Flowing down to the sea.The water picks up tiny amount of salts which it carries i to the ocean. The evaporation concentrates it there as the water goes round the cycle so ocean salinity gradually builds up.
Because the water is flowing into the ocean. It takes energy to move against the force of the water (fish swimming upstream). Dissolved material cannot do that