Sargassum on the Move

Over the past several years, Sargassum has been spreading in record numbers due to a combination of factors. New tracking methods are being developed to forecast its movement around the world to coastal communities. Water pollution prevention products can help mitigate the effects to shorelines.

Sargassum is an aquatic weed that forms in the Sargasso Sea. Spanning over 2 million square miles of ocean, it is the only sea without a land boundary, and is defined by its ocean currents. Without land boundaries, the algae are able to freely float around the ocean and reproduce on the high seas. This allows a further and wider spread of the sargassum.

Sargassum often washes up on shores, imperiling navigation, impeding tourism, and affecting coastal commercial fishing.  It can also be unpleasant. As large quantities accumulate and decompose it naturally gives off hydrogen sulfide gas, an odor similar to rotten eggs. Prolonged exposure to this off-gassing can even cause nausea, headaches, asthma problems and eye irritation.

However, Sargassum also serves a vital role. It is important to aquatic life, including crabs and shrimp. They hide in and under the weeds from bigger predatory fish, and they forage it for food.  It’s environmentally illegal to remove the seaweed in some coastal areas because of this. If it’s illegal to remove it, what can be done?

Keeping Sargassum at Bay with Debris Boom

One solution is to deflect the Sargassum to keep it offshore. A floating aquatic plant and debris boom forms a barrier to stop the spread of the sargassum. “If it’s done properly, booms can be very useful. We need to provide some triage. We clearly have to have BMPs in place to prevent the sargassum from hitting the beach,” said Brian LaPointe, a marine biologist researcher and professor  at FAU Harbor Branch Institute in Fort Pierce. The seaweed bumps up against this barrier, collects and then moves away with the tide to other areas. 

The Orion Aquatic Weed Control Boom offered by GEI Works can contain, deflect, or exclude sargassum in a variety of conditions. The debris booms can be used seasonally, long term, or permanently depending on the circumstances. Long-term options are mildew and UV-resistant with stronger PVC, a thicker ballast chain, and are temperature tolerant. The permanent boom is rugged with a molded foam-filled shell, steel weights, urethane coating, and heavy duty aluminum sliding connectors. 

The Past, Present and Future of Sargassum Seaweed

Brain LaPointe, a marine biologist, holding sargassum off shore.
The largest quantities of floating sargassum occurred recently in 2015. Many theories point to human intervention for the dramatic increase in sargassum.  In an interview with GEI Works, Brian LaPointe said, “Climate change is playing a role in this.” Warmer waters allow the sargassum to grow at a faster rate. 

He added that the 2010 BP oil spill cleanup may have also played a role. Corexit, a compound used in water to stop the spread of oil, may have dramatically increased the nitrogen levels in the Gulf of Mexico. The nitrogen acts as a fertilizer for sargassum causing the seaweed to bloom at faster rates. Also, toxic waste coming from sewage systems gets dumped into the rivers and that further adds to the nitrogen levels. 

However, this is partly speculation, and we aren’t fully able to pinpoint the cause and solutions with certainty. “We need to do more research,” LaPointe added. While some is known, a lot is still unknown. He also said that time will tell. A shift in sargassum patterns and cycles can reveal some about the causes. For instance, if sargassum begins to steadily decrease, then the BP Oil spill might have been a bigger factor than we even realized. Ongoing research is a vital tool for understanding sargassum and its future role in our aquatic ecosystem.

Governments and non-profit agencies are finding ways to track the seaweed and predict its spread and movement. One example is Texas A&M’s Sargassum Early Advisory System (SEAS), which uses satellite imagery to predict the levels of sargassum in different locations. It forecasts for: the Gulf Coast, Mexico, the Grand Caymans, Jamaica, Haiti, the Dominican Republic, Puerto Rico and many other Caribbean islands. The SEAS system identifies the path and factors of the sargassum cycle, understanding the nature of sargassum to create a more accurate forecasting model. It can help communities be prepared before it shows up on their shores.

Research and planning are important for communities in the path of sargassum. Learning to mitigate the effects with solutions such as our Orion Aquatic Boom can keep tourism alive, waters navigable, and communities healthy. 

If you need help with sargassum, contact GEI Works, and we can develop a solution for you.

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