Introduction to Sargassum
Sargassum, a type of seaweed, has been periodically blanketing Galveston beaches and other locales along the Texas coast, turning into a semi-annual event. Scientists are working to identify the reasons behind this phenomenon. Peter Morton, an associate research scientist with the Texas A&M Department of Oceanography, explains that sargassum has long been native to the Atlantic Ocean but has only recently begun to grow exponentially.
What is Sargassum?
Sargassum has always grown in the Sargasso Sea, with records dating back to Christopher Columbus’ voyage. However, what’s new is the formation of the Great Atlantic Sargassum Belt, which first appeared in 2011. This belt has extended far outside of the Sargasso Sea’s traditional boundaries, stretching from Africa to South America and eventually to North America.
The Great Atlantic Sargassum Belt
The natural currents of the Atlantic Ocean cause the Great Atlantic Sargassum Belt to periodically drift from Africa to South America and eventually to North America, where it is deposited on beaches along the Texas and Florida coastlines. Morton notes that the sargassum growth starts to take off around January or February off the coast of Africa and is then carried by ocean currents across the Atlantic.
Nutritional Composition of Sargassum
Morton’s area of expertise deals with the nutritional composition of sargassum, which has been changing over the past several decades. While sargassum typically needs nitrogen and phosphorus to survive, it has recently begun to substitute its need for phosphorus with other compounds such as arsenic. This substitution occurs when the sargassum is phosphorus-starved, resulting in a significant increase in arsenic levels.
Impact on the Environment and Human Health
The sargassum that washes up on shore is not dangerous to the beach-going public, but researchers are trying to understand what’s causing this change in nutrients and how it may be contributing to the seaweed’s exponential growth. Sargassum can have both positive and negative effects on the Atlantic ecosystem, providing a habitat for various organisms but also potentially threatening sea turtle nests.
Causes of the Influx of Sargassum
Researchers have not yet been able to confidently identify what is causing the influx of sargassum in the Atlantic. However, some of the leading theories suggest that human-made pollutants, such as industrial pollution, biomass burning, and Saharan dust, may be contributing to the growth of the Great Atlantic Sargassum Belt.
Conclusion
The sudden and rapid growth of sargassum in the Atlantic Ocean is a complex issue that requires further research to fully understand its causes and effects. While sargassum provides a habitat for various organisms, its exponential growth can have negative impacts on the environment and potentially threaten marine life. By continuing to study the nutritional composition and growth patterns of sargassum, scientists can work towards identifying the underlying causes of this phenomenon and developing strategies to mitigate its effects.
