Although freshwater and seawater are both major bodies of water on Earth, there are significant differences between them, which not only affect the distribution and adaptation of life, but also have a profound impact on human life and economic activities.
First of all, the most intuitive difference is the salt content. Freshwater, such as rivers, lakes and rainwater, has a very low salt content, usually less than 05 g liters. Seawater, on the other hand, contains a high concentration of sodium chloride and other mineral salts, which makes it taste salty and astringent, with a salt content of about 3About 5%, which is about 35 grams of liters.
Secondly, density is another important differentiating factor. Due to the presence of salinity in seawater, its density is greater than that of freshwater, averaging about 1025 grams of cubic centimeters, while the density of fresh water is about 1 gram cubic centimeter. This means that the same volume of seawater is heavier than freshwater, a property that affects the biodistribution and flow patterns of marine and freshwater ecosystems.
In addition, the distribution of freshwater and seawater is very different. Freshwater is mainly found in rivers, lakes, and groundwater systems on land, while seawater occupies most of the Earth's surface and covers the five oceans.
Color is also a differentiator between the two, albeit less obviously. Freshwater is usually colorless or light-colored, while seawater is usually blue due to the different ways in which it absorbs and scatters light.
Finally, there are differences in the availability and effects of freshwater and seawater on the human body. Fresh water is an important resource for human life and agricultural irrigation, and can be directly consumed. WhileDue to its high salinity, seawater cannot be directly drunk or used for irrigation, which needs to be desalted before it can be used by humans. At the same time, drinking seawater may cause the body to become dehydrated because the body needs to consume more water to thin the salt in the blood.
In summary, the differences between freshwater and seawater include, but are not limited to, salinity, density, distribution, color, and suitability for human use. Understanding these distinctions helps us better protect and use these two precious water resources, while also revealing the wonders of the diversity and complexity of the Earth's ecosystems.