By Theresa Pinto M.S., Contributing Reporter
MIAMI BEACH, FLORIDA – Beginning this Friday, Miami-Dade County will endeavor to rid the area’s beaches of the widely publicized Sargassum seaweed that has been washing up on Miami’s beaches in massive amounts and threatening local tourism.
Miami-Dade has up until now pushed the seaweed back out to the ocean, but will start using bulldozers and dump trucks to haul away an estimated 500,000 cubic feet of the seaweed in total and could cost up to $45 million for a year.
Mayor Carlos Jimenez told County Commissioners last week, “This is going to be a very difficult task to keep this under control, but we’re going to do the best that we can,” while announcing the emergency plan. They will have to take care not to disturb any sea turtle nesting sites or face repercussions from the State.
The County’s ‘Parks, Recreation, and Open Spaces Department’ is responsible for the project that will begin with ‘hot spots’ in Haulover and Bal Harbour, Miami Beach between 26th and 31st Streets, and the South Pointe jetty.
Sargassum has clogged up nearly every Caribbean beach from the Yucatan to Barbados. But Sargassum on beaches originates as part of a natural annual event where the macroalgae blooms and grows from a source in the Caribbean each summer.
Writers of the last century romanticized the Caribbean’s ‘Sargasso Sea,’ the only sea without a land barrier where swaths of free-floating sargassum, kept in the area by surrounding currents, create vital habitats for marine life.
However, since last year it has become a threat to local tourism as it washes up and rots on beaches, attracting nuisance pests and for some, blocking access to the oceans. Studies show that the rotting Sargassum can also give off toxic hydrogen sulfide gas.
The process is partly natural, but it is also exacerbated by warming oceans, meaning climate change, and possibly nutrient overloads from fertilizer runoff. This is similar to the reasons for the explosion in coastal Red Tide and toxic Blue-Green Algae in the area.
(Red Tide, another natural annual phenomena, made headlines last year when it caused massive fish kills and presented serious threats to marine mammals and some land mammals as well. The blue-green algal cyanobacteria is known to fill up local canals and can cause liver cancer.)
“The evidence for nutrient enrichment is preliminary and based on limited field data and other environmental data,” said Dr. Chuanmin Hu of the University of South Florida’s College of Marine Science, who led a study on the aptly titled Great Atlantic Sargassum Belt, representing 20 million tons of Sargassum biomass.
“On the other hand, based on the last twenty years of data, I can say that the belt is very likely to be a new normal,” said Hu.
Most other municipalities are also just pushing the seaweed back out to sea. Some are using booms and bouncers to keep the seaweed from ever coming ashore.
However some are looking into innovative measures, such as using the seaweed for biofuel feedstock, agricultural compost, or other bio-based products. The London Marathon in April made a large news splash when they handed out seaweed-packaged water instead of the plastic-bottled kind.
As for Miami-Dade’s collected Sargassum seaweed, it will initially be dumped in the County’s last remaining landfill, but they will seek out other alternatives for the future of new normal.