Introduction:
Living near the sea or ocean can be a wonderful experience, but it can also present certain challenges. One such challenge is the lack of accessible fresh water. This is primarily due to the fact that sea water is salty, making it unsuitable for drinking or other domestic uses. In this response, we will explore why sea water is salty and why people living near the sea or ocean feel a lack of water.

Why is sea water salty?
Sea water is primarily composed of water and dissolved salts. The main salt in sea water is sodium chloride, commonly known as table salt. The saltiness of sea water is a result of various processes that occur over millions of years.

- Weathering and erosion: Over time, rocks on land are gradually broken down into smaller particles through weathering and erosion. These particles are then carried by rivers and streams into the sea. They contain small amounts of minerals, including salts.
- Volcanic activity: Volcanic eruptions release gases and minerals into the atmosphere. Some of these minerals, such as chloride, are eventually washed into the sea.
- Sea floor spreading: The Earth's crust is constantly moving and spreading at the bottom of the ocean. This process brings up minerals from the mantle, contributing to the salt content of sea water.

Why can't people living near the sea or ocean use sea water?
While sea water is abundant, it cannot be used directly by people living near the sea or ocean due to its high salt content. Here are some reasons why sea water is not a viable source of water for human use:

- Health effects: Consuming large amounts of saltwater can lead to dehydration and other health issues. The high salt concentration can upset the balance of electrolytes in the body.
- Corrosiveness: Sea water is corrosive and can damage infrastructure and machinery that come into contact with it. This makes it unsuitable for various industrial uses.
- Impact on plants and agriculture: Saltwater can harm plants and crops by inhibiting their ability to absorb water and nutrients. It can also render soil infertile over time.
- Domestic use: Saltwater cannot be used for everyday activities such as cooking, bathing, or washing as it does not produce desirable results due to the high salt content.

Conclusion:
In conclusion, people living near the sea or ocean feel a lack of water because sea water is salty. Despite the abundance of seawater, its high salt content makes it unsuitable for various human uses. It is important for these communities to find alternative sources of freshwater to meet their daily needs.