Sargassum Invasion: What are the answers?

By Mike Jarrett

2018, November 1: The sun was high and barely a cloud in the sky. But, vendors who depend on the brisk weekend trade on the beaches on the south and west of Kingston Jamaica found only deserted stretches of white sand in the first week of July.

Punta Cana, Dominican Republic sargassum seaweed in Bavaro, Punta Cana, – June 24, 2018.

The bustle of activity normally expected on the beaches of Hellshire on a scorching Saturday afternoon was nowhere to be found … no beach volley ball; no children chasing each other; no vendors selling everything from oysters to wood carvings. Instead, there was an eerie quietness, disturbed only by an occasional gust out of the south, ripping through the sea grape branches.

The answer to the obvious question was not far away. It lined the beach as far as the eyes could sea and coloured the coastal waters brown. That which was left on the beach head during high tide was now rotting … stink from the rotting cells of dead flora and fauna and abuzz with flies

The lone vendor walked the long deserted beach in futility, kicking occasionally in disgust at a knot of the offensive sargassum that blew across his path. His brightly-coloured floatable toys would not make a childhood memory, not on this day. But he walks the deserted beach anyway, only because sitting, doing nothing, is the only alternative. He wonders ‑ like so many like him across the Caribbean region who depend on the beach for a livelihood ‑ when will this brown curse disappear.

Glenn Roach, PMAC’s Executive Secretary, writing from Barbados, noted the phenomenon in correspondence to members earlier that week.

“Large volumes of Sargassum seaweed are posing a substantial challenge to a number of Caribbean islands, though to various degrees. In Barbados the situation has been elevated to a national concern and the local Defence Force enlisted to assist in the clean-up efforts.”

Mr. Roach’s correspondence came immediately after similar correspondence from Sherman Williams about a sargassum invasion in the port, Blowing Point in Anguilla.

The invasion was not on one territory but stretched across Caribbean region.

Tulum, Mexico – workers load Sargassum seaweed into a truck at Playa Paraiso. August 2018:

The first

The first huge rafts of sargassum in the current phenomenon reportedly washed up on Eastern Caribbean shores in 2011. Professor Hazel Oxenford of the University of the West Indies (Cave Hill) told the BBC that it came as a surprise and no one knew what to do with it. In the years following the sargassum continued to flow into the Caribbean but apparently in larger quantities. In a matter of three years Caribbean governments knew they had a problem that posed a serious threat to national economies and, in particular, the tourism and fisheries sub-sectors.

Reports of business closures and loss of business proliferate. Horror stories of danger to the environment and about rafts of sargassum entangling and decimating whole bales of foraging sea turtles are a cause of grave concern to environmentalists. And reports about huge sums spent, to no avail, on heavy machinery to clean up private beaches have given real cause for consternation.

Clean-up at Playa del Carmen


What are the answers?

There are apparently no ‘quick fixes’ for this problem. Indeed, it could well get worse before it gets better. But a lot of study and observations have been done or are continuing. And progress is being made. Tourism ministries; port and harbour authorities and port and shoreline protection agencies must therefore keep abreast of the latest information and technology for dealing with sargassum.

The answers, such as there are, can only be found through study based on keen observation and meticulous data collection. []

SARGASSUM: What we know

Playa del Carmen, Mexico, April 19, 2019.
  1. Sargassum first appeared as a Caribbean region problem in 2011.
  2. It is brown seaweed that floats and is carried long distances by ocean currents.
  3. Ocean sargassum was historically pushed by currents from the Gulf of Mexico into the North Atlantic to float in the Sargasso Sea.
  4. Source of sargassum that appeared in the Caribbean in 2011 identified coming from a different source ‑ an area in the South Atlantic stretching from the Brasilian coast to West Africa.
  5. Sargassum is pushed by currents northwards, up the Brasilian coast, to the Caribbean Sea.
  6. Sargassum comes together to form huge floating rafts.
  7. Sargassum rafts can be as much as seven metres deep and several kilometres across.
  8. Incoming sargassum rafts smother sea grasses and coral reefs.
  9. Sargassum is not harmful to humans.
  10. Sargassum invasions normally affect southern and eastern coasts.
  11. Rafts block beaches and prevent near shore water sport activities.
  12. Sargassum endangers wildlife including sea turtles and coral reef systems.
  13. Sargassum stinks as it decomposes.
  14. Fishermen’s problems: entangles propellers, engines, nets and lines.
  15. Scientific analysis found that some sargassum were high in arsenic.
  16. Removal is time-consuming, expensive and can damage the beaches.
  17. Removal techniques have improved and management guidelines are becoming available. []

Mike Jarrett, Editor-in-chief