Depending on the right combination of currents and wind, a large mass of Sargassum "seaweed" circling the Gulf of Mexico may soon wash up along the US coast near Florida. The bloom, which is likely to be the largest ever recorded, is visible from space.
Sargassum is a leafy, rootless, buoyant algae that form large floating mats on the ocean floor. It can be found in the Sargasso Sea and was first mentioned by Christopher Columbus in 1492 when he was afraid his ship would become trapped in it.
Sargassum is an important habitat for marine species because it provides food, shelter, and breeding grounds.
Smelly Seaweed Bloom Heads To Florida
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It absorbs atmospheric carbon dioxide, an important greenhouse gas that contributes to global warming, through photosynthesis, just like other floating marine vegetation, as per Phys.org.
However, when tons of it accumulate along coastlines, it rots, emitting toxins such as hydrogen sulfide, which emits a pungent odor.
Depending on the amount, these toxins can cause headaches, eye irritation, and upset stomachs.
Algae mounds on beaches can harm marine ecosystems and disrupt recreational and fishing activities, costing communities millions of dollars.
Scientists have been tracking the massive accumulations of sargassum in the Atlantic Ocean since 2011.
However, this year's bloom could be the largest ever, spanning more than 8,800 kilometers from the coasts of Africa to the Gulf of Mexico and weighing 10 million tons.
ESA collaborates with CLS-NovaBlue Environment as part of the Earth Observation Science for Society initiative to monitor floating Sargassum using data from Earth observation satellites.
The Copernicus Sentinel-2 image above shows the Sargassum about 45 kilometers off the west coast of Guadeloupe. The Sargassum has been highlighted in bright red using the near-infrared channel of the image.
Furthermore, the Sargassum has been monitored by the Ocean Virtual Laboratory, which allows oceanographers to discover the world's oceans.
The virtual lab employs over 350 datasets, Copernicus Sentinel data, in situ measurements, and numerical model outputs to provide an unprecedented view of our oceans and improve scientific understanding of the ocean and coastal processes that lead to the Sargassum, which may soon affect Florida's coastlines.
Since 2011, there has been a change in the density and size of Sargassum levels, which can be tracked from space in a variety of ways.
Sentinel-2 multispectral satellite measurements at 10m resolution can capture the extent and evolution of the Sargassum belt that stretches across the Atlantic Ocean.
Radar altimeter measurements from the Sentinel-3 and Sentinel-6 satellites provide access to geostrophic ocean currents.
This means we can track the location, density, and size of Sargassum mats, as well as the path of ocean currents that are pushing Sargassum westward, threatening beaches in the Florida Keys, Mexico's Yucatán Peninsula, and the eastern Caribbean.
Algal blooms are becoming more common and larger in the Caribbean and West Africa as a result of rising water temperatures, fertilizer release into the ocean, and increased Sahara dust clouds, all of which promote algal growth.
Sargassum influxes are wreaking havoc on the environment, biodiversity, and coastal ecosystems.
For example, decaying sargassum can suffocate coral reefs and deprive fish of oxygen in coastal areas.
When marine mammals and turtles become entangled in algae, they frequently drown.
Barbados, Belize, and Trinidad and Tobago are among the hardest hit. When there is an abundance of sargassum, fishermen are forced to change their fishing techniques and target species.
It is critical to improving sargassum management. FAO not only advocates for best practices in sargassum cleanup and removal, but also collaborates with governments and communities to develop policies, standards, and incentives to protect public and environmental health.
FAO is also promoting ways to repurpose sargassum, turning it into commercially viable products to provide additional employment and income through the development of a sargassum uses guide.
In fact, small and medium-sized businesses are already using sargassum to make bricks, shoe soles, soaps, plant stimulants, and paper. Larger businesses are considering turning sargassum into renewable energy, bioplastics, and compost.
