What Are Dead Zones and What Causes Them?

If you are learning about the ocean or other natural bodies of water, you may have heard about the concept of a dead zone. A dead zone, also known as hypoxia, is when a part of a body of water has less oxygen than normal, which causes life to not form or develop in that area of water. Dead zones are becoming more common overtime because of actions that us humans do. 

What Causes Dead Zones?

There are many ways that dead zones can form. A primary reason why dead zones exist are because of nutrient pollution. The nutrients can cause algae in a body of water to grow rapidly which leads to algal

blooms. The algae requires a lot of oxygen and can also block sunlight from penetrating the water in order for water plants to grow which can create oxygen. Since oxygen depletes, this causes a dead zone. Algal blooms are the most common reasons why dead zones exist. Hypoxia can also occur when freshwater and seawater mix at a meeting point. This combination makes it difficult for life to grow, thus making it a dead zone.

How do we Create Dead Zones?

A main way that us humans can increase the chances of dead zones occurring is by farming. Fertilizers with phosphorus and other nutrients cause nutrient runoff which leads to lakes, rivers, bays, and more. When an excess amount of nutrients end up in the water, algae takes advantage of it which creates algal blooms.

It may not seem like dead zones affect us, but it can contaminate the water that we drink. Dead zones can also create more bacteria that could be spread to different rivers, lakes, or oceans that some people may swim in. Climate change can also have a negative effect on dead zones. If we do simple changes to our life, it can slowly decrease the chances of dead zones. Changing different actions in our life can also eventually save our planet as a whole.