Oceanic waters are the entire totality of water as a resource contained in the World Ocean. It is composed of the Pacific, Atlantic, Arctic and Indian oceans. Salinity is measured in thousandths, otherwise they are called ppm.
The average salinity of the World Ocean is 35 ppm - this figure is most often called in statistics. Slightly more accurate value, without rounding: 34, 73 ppm. In practice, this means that about 35 g of salt must be dissolved in each liter of theoretical ocean water. In practice, this value varies quite a lot, since the World Ocean is so huge that the waters in it cannot quickly mix and form a space that is homogeneous in terms of chemical properties.
The salinity of the ocean depends on several factors. First, it is determined by the percentage of water evaporating from the ocean and precipitation falling into it. If there is a lot of precipitation, the level of local salinity decreases, and if there is no precipitation, but the water evaporates intensively, then the salinity increases. Therefore, in the tropics, in certain seasons, the salinity of water reaches record values for the planet. The saltiest part of the ocean is the Red Sea, with a salinity of 43 ppm.
Moreover, even if the salt content on the surface of the sea or ocean fluctuates, usually these changes practically do not affect the deep layers of water. Surface fluctuations rarely exceed 6 ppm. In some areas, the salinity of the water decreases due to the abundance of fresh rivers flowing into the seas.
The salinity of the Pacific and Altantic oceans is slightly higher than the rest: it is 34, 87 ppm. The Indian Ocean has a salinity of 34.58 ppm. The lowest salinity is in the Arctic Ocean, and the reason for this is the melting of polar ice, which is especially intense in the Southern Hemisphere. The currents of the Arctic Ocean also affect the Indian, which is why its salinity is lower than that of the Atlantic and Pacific Ocean.
The farther from the poles, the higher the salinity of the ocean, for the same reasons. However, the saltiest latitudes are 3 to 20 degrees in both directions from the equator, not the equator itself. Sometimes these "bands" are even said to be salinity belts. The reason for this distribution is that the equator is a zone of constant heavy torrential tropical rainfall, which desalinates the water.