A Seaweed Problem

It’s an invasion.

Throughout the year, countless Caribbean beaches and bays have turned reddish brown as the air has become thick with the odor of rotting eggs.

From the sky, it is evident there is no relief in sight as long strands of reddish seaweed — that resemble oil slicks — approach nearby islands that are already inundated with the decaying vegetation.

The culprit is sargassum: brown algae seaweed that floats with the ocean currents. It never attaches to the seabed and is only found in the Atlantic. Scientists say warmer temperatures are to blame for the sargassum bloom.

The seaweed has many benefits, such as providing habitat for more than 200 species of fish and invertebrates; however, the influx of sargassum is now becoming a problem in the Caribbean both on land and at sea.

“It’s been a bit of an unexpected result of climate change, changing ocean currents and higher temperatures and so on, and probably will continue,” said Shannon Gore, a marine biologist in the BVI. “In 2011 we saw it as well, but at least it is not as extensive as some of the islands further south.”

Sailors and boaters have struggled with the sargassum. In May, organizers of the Puerto Rico Heineken International Regatta offered to tow sailors to the racecourse due to the large amount of sargassum near the entrance of the marina. On the press boat, a 14-foot rib, the engine became entangled with the seaweed on several occasions, which almost brought the vessel to a standstill.

In late 2014, a ferry company in Tortola halted its service for about a month after sargassum engulfed the Road Town Ferry Terminal. The ferry owner, Albion Hodge, claimed that the seaweed was being sucked up into his ferry’s engine, which then required mechanical repairs.

Efforts to clean up have included the use of heavy machinery and lots of volunteers with rakes, shovels and garbage bags. But in most cases as soon as the seaweed is cleared from an area, it returns in the following days or weeks. Scientists say sometimes the best option is to let the seaweed decompose, where it will provide nutrients for surrounding flora and fauna. But when the sargassum starts to pile up more than three-feet high, it then becomes a threat to wildlife and a nuisance to residents and visitors.

In Barbados, at least 42 sea turtles suffocated in the sargassum when they tried to reach the water and became trapped in the seaweed, according to the Barbados Sea Turtle Project. On June 30, the organization responded to reports of several dead turtles on Long Beach.

“The Barbados Sea Turtle Project is saddened to report that 37 dead turtles were recovered from Long Beach yesterday …” the organization reported on its Facebook page. “Project staff spent hours pulling turtles from the surf. These turtles, both critically endangered Hawksbills and endangered Greens were being revealed as the immense banks of sargassum on shore eroded.”

Scientists warn that removing the large heaps of seaweed needs to be done properly or it can be just as hazardous to the wildlife. Raking is preferred to large machinery that could crush turtles that are entangled in the sargassum or promote beach erosion.

However, some have found beneficial uses for the sargassum as fertilizer and compost, but others have struggled with the smell and the sight of the seaweed, which continues to plague residential and tourist areas.

Various hotel and tourism associations around the region, including the Caribbean Tourism Organization and the Caribbean Hotel and Tourism Association, are looking at strategies to cope with the overwhelming amount of seaweed, which cannot be effectively managed with rakes and shovels alone.

“We’re going to have to work as one to really combat this thing — it is a massive problem,” CTO Chariman Richard Sealy said. “It is not a seasonal problem anymore, nor is it beach specific.”

Todd VanSickle is a journalist living and working in the Virgin Islands.