What is the Difference Between Freshwater and Saltwater

The main difference between freshwater and saltwater is that freshwater has a lower salt concentration and density than saltwater.

We can categorize the water on Earth into two categories as freshwater and saltwater. Saltwater or seawater is the water in oceans and seas. Other sources of water on Earth, including frozen and meltwater, natural precipitations, surface runoffs, and groundwater, fall under the category of freshwater.

Key Areas Covered

1. What is Freshwater
     – Definition, Features 
2. What is Saltwater
     – Definition, Features 
3. Difference Between Freshwater and Saltwater
     – Comparison of Key Differences

Key Terms

Freshwater, Saltwater

What is Freshwater

Freshwater is naturally occurring water that contains a low concentration of salts and other dissolved solids. Freshwater is vital for human and animal lives on Earth. However, only 3% of the water on Earth is freshwater. It is present in various water bodies such as lakes, ponds, reservoirs, rivers, wetlands, glaciers, icebergs, etc. These sources include frozen and meltwater, natural precipitations, surface runoffs, as well as groundwater. Freshwater habitats are usually less than 1% of the Earth’s total surface area. But it is also home to around 40% of fish species and 10% of all animals.

Freshwater has a very low salt concentration compared to saltwater, even less than 1%. Plants and animals inhabiting freshwater bodies are adapted to this low concentration. Therefore, they cannot survive in areas with high salt concentrations. Other notable features that set freshwater apart from seawater include its lower density and freezing point of 0 degrees Celsius. Although freshwater is critical to life on Earth, it faces threats from many forces, including overdevelopment, global warming, and polluted runoff.

What is Saltwater

Saltwater is water found in oceans and seas. It has a high concentration of salt, hence the name saltwater. Most of the water found on Earth is saltwater. In fact, it covers more than 70% of Earth’s surface. The saltwater on Earth functions as a heat reservoir and mainly influences weather patterns and climate, as well as the water cycle. Therefore, saltwater also plays an important role in the existence of plant and animal life on Earth.

Seawater is a complex mixture of water, salt, and other dissolved organic and inorganic materials. It serves as a rich source of commercially important chemical elements. We can obtain sodium chloride or table salt from evaporating seawater. In addition, we also derive large quantities of magnesium and bromine from seawater. Moreover, when seawater is desalted, it can serve as a supply of drinking water.

Difference Between Freshwater and Saltwater

Definition

Freshwater is naturally occurring water that contains a low concentration of salts and other dissolved solids, while saltwater is water found in oceans and seas.

Sources

Freshwater is found in lakes, reservoirs, rivers, wetlands, glaciers, ice caps, underground, etc., while saltwater is found in seas and oceans.

Salt Concentration

While freshwater has a very low concentration of salt, seawater has a high concentration of salt.

Density

Seawater has a higher density than freshwater. Freshwater has a density of 1 g/ml, whereas saltwater has an average density of around 1.025 g/ml. This difference is due to the variation in salt concentration.

Freezing Point

The freezing point of freshwater is 0°C, while the freezing point of saltwater is -2°C.

Conclusion

Saltwater or seawater is the water in oceans and seas. Other sources of water on Earth, including meltwater, natural precipitations, surface runoffs, and groundwater, fall under the category of freshwater. The main difference between freshwater and saltwater is that freshwater has a lower salt concentration and density than saltwater.

Reference:

1. “Seawater.” Encyclopædia Britannica, Encyclopædia Britannica, Inc.
2. “What Is Freshwater and Where Is It Found?” WWF, World Wildlife Fund.

Image Courtesy:

1. “Lake, mountain peak, reflection, national park, spectacular, majestic, idyllic, snow, mountain, landscape” (CC0) via Pixino
2. “Sea, waves, shore, wave, body of water, ocean, wind wave, coastal and oceanic landforms, coast, sky, horizon, beach, water” (CC0) via Pxhere