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Hypoxic zones, also known as dead zones, are areas in the oceans and seas where dissolved oxygen levels are extremely low.
This occurs mainly due to pollution caused by nutrient run-off from agriculture, industry and sewage.
When there is an excess of nutrients, such as nitrogen and phosphorus, in the water, excessive growth of algae and phytoplankton occurs.
As these aquatic plants die and decompose, microorganisms consume the dissolved oxygen in the decomposition process.
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As a result, oxygen levels in the water decrease dramatically, creating hypoxic conditions.
This has serious consequences for marine life, as many organisms cannot survive in environments with low oxygen levels. Fish and other aquatic animals are forced to leave these areas or die from suffocation.
Hypoxic zones can have a devastating impact on marine ecosystems, as they can cause massive die-offs of fish and other marine species, and can also affect fishing communities and the economy of coastal regions dependent on fisheries.
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To address this problem, it is important to take measures to reduce pollution and control the flow of nutrients into the oceans and seas. This involves implementing better agricultural practices, treating wastewater properly and reducing industrial pollution.
The world's largest hypoxic zones include the Dead Zone in the Gulf of Mexico, the Baltic Sea and the Black Sea. These areas suffer from low oxygen levels due to pollution and nutrient run-off.
Marine life is negatively affected in these unfriendly areas.