Nearly four years removed from what Galveston locals dubbed the "Summer of Seaweed," Dr. Gilbert Rowe's olfactory memory vividly recalls the fetid, pungent aroma from the mats of reddish brown sargassum that stretched for miles down the Texas coastline.

"I hated the smell," Rowe said. "The smell was nauseating. Kind of an organic thing, not like dead fish, not like rotten egg, something else about it."

Ever since the summer of 2014, when Galveston beaches were inundated – some say "invaded" – by massive piles of seaweed, driving away beach tourists and hurting the local economy, scientists and marine biologists have struggled to gain definitive answers as to why this phenomenon happened, and why it hasn't recurred.

Rowe, a benthic ecology professor at Texas A&M Galveston, is one of 45 scientists from the United States, France and western Africa that gathered at the university recently to search for answers to these questions about sargassum, and pool resources for future research.

The French have been grappling with sargassum epidemics on the islands of Martinique and Guadeloupe, and the west coast of Africa, particularly the Ivory Coast, has also been hit hard by the sea plant.

"What we wanted to do is put them together so they can really screen all of the topics where we have joint interest and see where we can help them bridge in a stronger way and also find some resources and funding to help them structure their cooperation," said Dr. Minh-Hà Pham, the counselor for science and technology at the French Embassy.

Texas A&M Galveston has largely led the way in forecasting sargassum invasions, thanks to its Sargassum Early Warning System (SEAS), a satellite that tracks sargassum in the Gulf of Mexico. And while that system can give Galveston up to two weeks notice with no cloud cover, it still leaves scientists wanting more information on its taxonomy, carbon emissions and long-term migratory patterns. Sargassum originates in the Sargasso Sea, a region of the north Atlantic bound by a system of circulating ocean currents.

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"If there's sargassum out there, we can see it and we can tell where it's going," said Dr. Tom Linton, a marine scientist at Texas A&M Galveston and one of the founders of the sargassum workshop. "But if we get into this thing collectively with oceanographers and meteorologists and people that do remote sensing, we get a better predictive model if we understand the factors that influence the ocean currents – El Niño, La Niña, the south Atlantic oscillation – and changes in the ocean surface temperature."

The sargassum conundrum goes well beyond its unpredictable migration patterns.

One of the topics of discussion at the workshop last week was how to properly remove the seaweed from beaches when it arrives en masse like it did in 2014, and what to do with it when it's removed.

Harvesting sargassum while it's still out in the ocean is not an option as the clusters of seaweed are thought to be critical early-life-stage habitats for commercial and recreational fisheries, including big dolphinfish like mahi-mahi.

"You can't really harvest it at sea so it won't come to shore because of its ecological importance and at the same time, once it gets on shore what do you do with it?" Rowe said.

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Kelly de Schaun, the executive director of Galveston's Parks Board was faced with that exact problem in the 2014 Summer of Seaweed, torn between the conventional wisdom of leaving seaweed in its place on the sand, and the hard economic reality of tourists fleeing the beaches because of its acrid, sulphuric smell.

That summer, the seaweed was removed with frontloading bulldozers, and some of it was deposited to reinforce dunes on Galveston's coastline. De Schaun said the parks board is now much better prepared for a sargassum recurrence, with improved practices and mechanisms for seaweed removal that won't contribute to the erosion of the city's beaches, including a machine called a "surf rake" that collects the seaweed on a conveyor belt that allows excess grains of sand to fall back down to the beach.

"We identified which areas we were going to move seaweed, what the front threshold was to begin to move seaweed, we invested in heavy-duty equipment that was environmentally responsible, and then we trained our own staff on protected and endangered animals and built a program for interns for Texas A&M to assist us in wildlife monitoring on the beach," de Schaun said.

At the conclusion of the three-day conference in Galveston, attendees were encouraged by the progress made, and all parties involved committed to a memorandum of understanding that there would be a follow-up conference later in the year, possibly hosted by the French on one of the Antilles Islands in the Caribbean.

Linton said the ultimate goal was to develop an international sargassum research consortium between all the nations affected by it.

"We could have real-time communications between Galveston, Ivory Coast and Martinique and Nice, France and Cancun, Mexico – we could all be looking at satellite images and how it relates to our particular corner of the world," Linton said.

"It's a heady time for us to be working on this. Everybody by the end of the conference was like, 'Let's go do this.'"

Galveston beachgoers – and their noses – will undoubtedly be thankful for their efforts.