Salinity also has an affect on ocean currents. Near Iceland, if the ocean is not salty enough, the water can't get dense enough to sink. Salinity also has an affect on ocean currents. Near Iceland, if the ocean is not salty enough, the water can't get dense enough to sink. As global warming melts ice in places like greenland, the water gets fresher and sinks slower. this could slow or stop the gulfstream, or perhaps just redirect it.