Report by Samyukta Mallick
A large mass of seaweed is floating towards the beaches of the southern United States and Mexico. This seaweed is called sargassum.
What is Sargassum?
Sargassum is a large brown seaweed and a type of algae. It floats near islands and landmasses and never attaches to the seafloor. It is found in the Atlantic Ocean and the Gulf of Mexico. Sargassum travels on water currents. It accumulates into a large mat and then is carried through the Caribbean Sea and ends up on various shores.
Why is Sargassum vital?
Sargassum is important for the oceans because it plays a role in keeping the shore stabilized and controlling the sand erosion. It helps nourish the beach and keep its sand replenished. The seaweed is also home to more than 120 species of fish and invertebrates. The sea birds also look to the Sargassum for food and several plants feed on its nutrients.
Why is it causing a problem now?
Sargassum seaweed belts have been approaching these beaches since 2011. Every year, the mass seems to grow in size. Now, it is called the ‘Great Atlantic Sargassum Belt’. As of 2023, it is 5,000 miles (8,000 kilometers) long. It weighs 13 million tons.
What are some of the issues it causes?
The large mass of Sargassum causes multiple problems when it lands on shore.
Seaweed that remains on land starts decomposing. Then, it releases hydrogen sulfide. This gas spreads an unpleasant odour. It is not significantly dangerous to humans, but the inhalation may cause mild irritation in the respiratory system and eyes. When Sargassum floats underwater, it may entangle species like turtles and dolphins, preventing them from surfacing for air.
During the turtle nesting season, the sargassum makes it difficult for mother sea turtles to lay eggs and for baby turtles to reach the sea. This is because the Sargassum blocks the sand. This season is from May through October. Special permits must be taken to allow equipment to help manage seaweed and help the turtle population.
What can be done?
Removing the heavy sargassum from the beaches is a difficult and expensive task. Even after clearing the beaches, the challenge of using the sargassum remains. The seaweed that is removed from the shore end up in a landfill.
The sargassum grows faster in warm waters. Climate change is part of the issue. Scientists also believe that the amount of fertilizer in the ocean is the cause of the unusual growth of the seaweed.
Scientists are already trying to develop theories to use Sargassum as biofuel, compost, medicine, and fertilizer.
