The Great Atlantic Sargassum Belt, a vast stretch of seaweed that resides between the Gulf of Mexico and the West Coast of Africa, is experiencing an unprecedented bloom this year. The brown macroalgae, also known as sargassum, is a natural occurrence that provides a home for countless marine life and helps to absorb carbon from the atmosphere. However, this year’s bloom is causing concern as it is four times larger than ever before and can even be seen from space.
The Caribbean islands have been battling the effects of the massive seaweed bloom for months, and now, the floating mats of sargassum are making their way toward the Florida coastline. The seaweed, which floats just beneath the surface of the water, as a result of built-in air pods that keep it buoyant, is expected to cause problems for Florida’s tourism and fishing industries.
Environmental Implications Of Massive Accumulation Of Sargassum
While sargassum is not uncommon on beaches, this year’s bloom is an unusual occurrence and could have far-reaching environmental implications. The buildup of the brown macro algae can cause a range of problems, including the emission of toxins like hydrogen sulfide, which produces a pungent smell and can cause headaches, eye irritation, and upset stomachs, depending on the quantity.
The massive amounts of seaweed that collect along coastlines can also harm marine ecosystems and disrupt recreation and fishing, costing communities millions.
Sargassum has existed for centuries, Christopher Columbus encountered sargassum during his voyages in 1492, and later sailors also encountered the seaweed, which led to the naming of the Sargasso Sea. However, in recent years, the buildup of sargassum has reached high levels due to a combination of climate change and pollution.
According to scientists, the warming of ocean waters and the inflow of nitrogen and man-made fertilizer from rivers have caused an exponential growth of sargassum over the past decade. These factors have created the ideal conditions for the algae to flourish, leading to massive blooms that can stretch for miles and impact coastal communities from the Caribbean to Florida.
Space Technology Aiding Monitoring And Management Of Sargassum Blooms
For over a decade, scientists have been tracking the formation of large sargassum blooms in the Atlantic Ocean. This brown macroalgae has been known to form large accumulations, but this year’s bloom could be the largest ever recorded.
As the massive sargassum bloom threatens coastal communities in the Caribbean and Florida, the European Space Agency (ESA) is using its Earth Observation Science for Society initiative to monitor the floating algae. Working alongside CLS-NovaBlue Environment, ESA is using data from Earth observation satellites to track the growth and movement of sargassum blooms.
The Copernicus Sentinel-2 images captured by the satellites provide a clear view of the sargassum, highlighting its location and extent. These images can be used to monitor the bloom and to predict its movement, helping authorities to prepare and respond to its impact on coastal communities and marine ecosystems.
ESA’s Report On The Change In The Density And Size Of Sargassum
According to a report released by ESA, in recent years, a significant change in the density and size of sargassum levels has been observed. The report highlights that these changes have been monitored through various means from space since 2011.
One of the means used in monitoring the sargassum is the Ocean Virtual Laboratory, which is a state-of-the-art tool that allows researchers to monitor sargassum levels in real-time, and to analyze data from various sources.
Using multispectral satellite measurements from Sentinel-2 at a resolution of 10m, the extent and development of the sargassum belt can be captured as it stretches across the Atlantic Ocean. This data is then combined with radar altimeter measurements from Sentinel-3 and Sentinel-6 satellites, providing access to geostrophic ocean currents.
As a result, the location, density, and size of sargassum mats can be tracked, along with the trajectory of ocean currents leading the sargassum westward. This poses a significant threat to beaches along the Florida Keys, Mexico’s Yucatán Peninsula, and the eastern Caribbean.
The report emphasizes that the ability to monitor sargassum levels and ocean currents from space provides a critical tool for coastal management and protection. It highlights the urgent need for more research to better understand the drivers of these changes and their impact on coastal ecosystems and communities.