Scientists Discover Massive Seaweed Patch Stretching From Mexico to Africa
By Elias Marat
A humongous mass of heavy, stinking seaweed stretching from the Gulf of Mexico to West Africa has already become the biggest seaweed bloom in recorded history, according to the journal Science.
And the Great Atlantic Sargassum Belt, as it is now known, could be a sign of a “new normal” wrought by deforestation and the use of fertilizer. The giant mass of seaweed is comprised of a species of macroalgae called sargassum, a brown seaweed that forms bubbles resembling grapes.
Floating mats of the stringy seaweed were first reported in the center of the North Atlantic by Christopher Columbus over four centuries ago, but never on such a scale as today.
The belt now extends about 5,500 miles and has a total biomass weight of a stunning 20 million tons, according to the new study.
The seaweed can be considered an asset to marine wildlife for its value as a raft-like habitat for fish, turtles and birds. In small amounts, it can also provide sustenance on beaches.
But in excessive amounts, thick mats of the floating seaweed can die and sink to the ocean floor where they crush and kill marine life, endangering coral and seagrasses.
Researchers looked at 19 years of satellite records in their study of the seaweed, which began to bloom drastically in 2011 and inundate shorelines.
Scientists believe that the abundance of nutrients like nitrogen and phosphorus running off from West Africa’s coast into the ocean every winter is partially to blame. The belt is also fed by similar nutrients from fertilizer and deforestation that are running off into the Amazon River—and subsequently into the ocean—during the summer time.
With the assistance of warming climate conditions, the sargassum consumes the extra nutrients and grows. The seaweed also leaves sargassum seeds throughout the ocean, ensuring further growth of the belt.
Dr. Chuanmin Hu of the University of South Florida College of Marine Science, who led the study, told BBC:
The ocean’s chemistry must have changed in order for the blooms to get so out of hand.
This is all ultimately related to climate change because it affects precipitation and ocean circulation and even human activities, but what we’ve shown is that these blooms do not occur because of increased water temperature.
They are probably here to stay.
Omar Vázquez, originario de Jalisco, lleva cinco años trabajando con el sargazo, primero como fertilizante y ahora como ingrediente para hacer ladrillos con los que construir casas a bajo coste https://t.co/pMcXwCsbzq pic.twitter.com/F1ovAHmu8E
— EL PAÍS América (@elpais_america) July 5, 2019
The seaweed has also damaged local economies, resulting in violence and social strife, according to officials in Mexico.
Almost 621 miles of Mexican beaches have been stained brown by the coffee-colored foam brought by the seaweed. The sargassum has blighted once-pristine beaches with the fetid stench of gassy, rotten eggs, leaving generally murky and swamp-like conditions in its wake. The malodorous seaweed has devastated tourist destinations across Mexico’s coastline.
Mexican President Andres Manuel Lopez Obrador has declared that the “sargazo” is being treated as a national priority by authorities, with Secretary of the Navy Rafael Ojeda tasked to directly lead efforts to contain the seaweed bloom. Ojeda has pledged to devote Mexican Navy efforts toward building 4 “sargaceras” and rehabilitating another that would collect the seaweed from Mexico’s Caribbean Coast.
However, the removal of the seaweed is a time-consuming, labor-intensive and costly process that fails to address the root cause of the bloom.
The seaweed bloom is just the latest sign that the toxic waste left in our oceans and rivers by large industries—aided and abetted by their own national governments—is leaving an indelible mark on nature and society.