Volume 239, March 25, 2023

Atlantic Ocean Off Florida Spawns a Giant Sargassum Blob Due to Climate Change, Nutrient Pollution


In the central Atlantic Ocean, there is a belt characterized by massive floating mats of seaweed called sargassum. The belt stretches from West Africa to the Gulf of Mexico, covering an area of approximately 3,417,000 square miles.

 

The Sargasso Sea is to the north, bounded by currents to become a sea within the Atlantic Ocean. It is known for vast floating mats of leafy marine algae with spherical float bladders that reminded Columbus of grapes, called Sargassum. This seaweed lives entirely away from land, unlike most other seaweeds with holdfasts that anchor it to the substrate.  

 

The sargassum provides a habitat for diverse marine life, an oasis in a nutrient-poor sea. Sargassum shelters mahi-mahi, tuna, and young sea turtles and houses stay-at-home seahorses, fish, crabs, and invertebrates that have evolved to resemble Sargassum. 

 

Sargassum has recently flourished in a body of water separate from the Sargasso Sea. The Azores Current flows south to where the African continent recedes from the Americas. Here the current splits and goes in two directions. Some current flows West to encircle the bottom of the Sargasso Sea, and some current flows Southeast to join the Westerly Equatorial Drift. Because the Earth spins to the East, the Equatorial Drift goes West. It is from this sea, formed by the Westerly flowing Azores Current on the north side and the Westerly Equatorial Current to the south that the Sargassum Blob threatens Florida.

 

This direct result of climate change dramatically increases the nutrient loading into this portion of the Atlantic Ocean from three directions. More nutrient-rich cold Arctic waters are flowing into the Atlantic Ocean due to the more open Arctic Ocean. When sea ice forms, it consists of fresh water. Salts left behind make the cold water around the ice denser. This briny water sinks to displace water laterally. This is called thermohaline circulation. In the Denmark Strait between Iceland and Greenland, cold, nutrient-rich Arctic waters meet warm, nutrient-poor Atlantic waters and plunge down 11,000 feet to flow south beneath the less dense seawater. 

 

In Sahara, Africa, climate change has brought longer dry periods. The land dries, and the prevailing Westerly winds carry more dust out over the Atlantic to seed the waters with more nutrients.  


Finally, more extreme weather events, the cutting of forests, and excessive amounts of fertilizer cause significantly more nutrients to wash down rivers and off the land into the sea. And the green sargassum grows all about.

The good news is that the ocean is pulling more carbon out of the atmosphere than ever before, creating lots of biomass and entire ecosystems full of marine life. The bad news is when all that organic carbon arrives on Florida’s shores.  

 

Unfortunately, because it is always complex, there is more bad news. Corexit, a toxic forever chemical used as a dispersant to break up oil spills in the Gulf of Mexico, has been found in Sargassum Weed. 

 

When large quantities of Sargassum wash up on beaches, it can make the sand unsightly and cause a foul smell akin to rotten eggs, causing respiratory problems. The large mats of Sargassum can also make navigation difficult for boats and ships, particularly those with propellers. This can pose a safety hazard and increase the risk of accidents. Fishing derbies are canceled at great expense. 

 

Sargassum blooms coming to shore can negatively impact marine life, particularly sea turtles. When the seaweed accumulates in large amounts, it can trap baby sea turtles trying to make their way to the ocean. It can also smother and kill sea grasses, other marine plants, essential habitats, and food sources for many species.

 

As Sargassum breaks down, it releases organic matter that can lead to oxygen depletion in the water. This can create "dead zones" that harm fish and other marine life.

 

While Sargassum is a crucial component of ocean ecosystems, excessive amounts can negatively impact the environment and economy of coastal regions.

 

As we continue to see the unintended consequences of rising global temperatures and the use of harmful chemicals, it becomes even more apparent that everything is connected– from the Arctic Ocean, the Sahara Desert, and rivers to the Atlantic Ocean to the coast of Florida. 

 

Everyone must do their part to combat the climate crisis. From not fertilizing your lawn to pressuring our lawmakers to take big, bold action to reduce emissions and increase the drawing down of carbon, our efforts will make a world of difference.

Yankee Penguin


Having sailed the Drake to the South Shetland Islands through the English Channel, never seeing land for the clouds, turning South along snow-covered Greenwich Island, we came to Yankee Harbor, where seals, giant petrels, and gentoo penguins greet you on the beach. A few chinstrap penguins stood off to one side, looking like sentries. I stopped on a rocky outcropping while my shipmates walked on for a more intimate encounter with the seaward end of a glacier. I sat down on a boulder and discovered I had the delightful company of a gentoo penguin with his own rock. This is his story to trumpet.


Gentoo penguin hopping about on a rock with friends.

“the answer to every problem involved penguins”

― Rick Riordan, The Throne of Fire

“Because penguins are so beloved, they are uniquely capable of teaching us about love for the natural world.”

― Charles Bergman, Every Penguin in the World: A Quest to See Them All


Dear Yankee Penguin and Rob, . . . .

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Publications:


Massachusetts Slow Water Drought Relief Carbon Offset Fund


Massachusetts Let Forests Grow Carbon Offset Fund


"Saving Forests with Carbon Offset Rewards for Not Cutting, Let Forests Grow Old." E The Environmental Magazine, March 14, 2023


"Slowing Water For Greener Neighborhoods." The Environmental Magazine, December 18, 2022


"Speak for the trees: President Biden should protect public forests." Illuminem, December 18, 2022


"Slowing Water for Greener Neighborhoods." Illuminem, December 9, 2022


"Top Gun at COP27. It's not the plane. It's the pilot." The Environmental Magazine, November 29, 2022


"Biden’s game-changing administrative actions for climate at COP27." illuminem Voices, November 19, 2022


"Taking action to improve plight of right whales." Boston Herald, November 9, 2022


"Revival Coffee in Somerville takes up the Natural Lawn Challenge." The Somerville Times, August 27, 2022


"For eco groups, less lawn fertilizer is key to water crisis." By Dustin Luca, Salem News August 12, 2022


More carbon capture, better water retention and greener emerald bracelets for Dedham.” The Dedham Times, August 12, 2022.


“Emerald Bracelets to Solve Three Of The World’s Greatest Environmental Problems.” by Rob Moir, The Environmental Magazine, June 21, 2022


"Of Mousy and Elephantine Cycles, Managing the CLIMATE CRISIS after Glasgow COP26." The Eden, March 2022



“Lincoln resident promotes natural lawn care,” Concord Journal, Aug 3, 2021


Zumi’s host Natural Lawn Care for Healthy Soils Challenge,Ipswich Chronicle Transcript, Aug 10, 2021


Peabody peak capacity generator need not burn fossil fuels,” The Salem News, Aug 5, 2021 


30% preserved or restored by 2030,” The Salem News, Sep 29, 2021


Pogie deaths, a Mystic River mystery,” Boston Herald, Oct 4, 2021


Remember the right whales with a special day,” CommonWealth, Oct 29, 2021


Retreating Arctic Sea Ice, Sea Ice Formation, and the Stronger Flow of the Gulf Stream” Seven Seas November 2021


"Rob Moir, PhD, Science Advocate," Bloomberg Business, April 11, 2022

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