A giant ‘dead zone’ – an area of ocean with low oxygen content – in the Gulf of Mexico continues to grow and could reach its record level in 2019, warn the scientists of the National Oceanic and Atmospheric Administration.
The forecast for 2019 is approaching the record level of about 22,700 square kilometers, established in 2017. It is expected to be greater than the five-year average of about 14,900 square kilometers, says the NOAA statement.
The ‘dead zone’ of the Gulf of Mexico, considered one of the largest in the world, emerges every year. It is caused mainly by excess nutrient pollution from human activities, such as urbanization and agriculture, that occur throughout the Mississippi River basin, specialists explain.
Once the excess nutrients reach the gulf, they stimulate the excessive growth of algae, which eventually die, and then sink and decompose in the water. As a result, the level of oxygen decreases considerably, which becomes insufficient to maintain the majority of marine life.
An area the size of New Jersey could become almost completely sterile this summer, which would pose a threat to marine species, and to fishermen who depend on them.
An important factor contributing to the growth of this year’s ‘dead zone’ is the abnormally high amount of spring rainfall in many parts of the Mississippi River basin, which led to high river flows and much greater nutrients in the Gulf of Mexico.
In recent years, ecologists and oceanographers are increasingly discovering that global warming accelerates the growth of these areas, especially in the tropical and equatorial regions.