Sargassum Seaweed: A Source of Economic Opportunity

September 6, 2019 by Rob Steir

Sargassum seaweed (“SSwd”) has become a major annual problem for destination beach cities throughout Florida and the Caribbean. A recent academic research report estimated over 20 million tons of it existed, in 2018, over a 5,000 mile stretch of the Atlantic Ocean. Much of it winds up in big stinky rotting clumps on beaches. The annual cleanup costs to collect, transport and landfill sargassum seaweed has been estimated to be about $35 million in Miami Dade County for 2019, and $120 million in the Caribbean for 2018. These costs do not take into account the economic impact of lost tourism bookings, nor the long-term negative PR that occur whenever a tourist snaps a picture of seaweed covering a beach, or googles a destination and finds an article about the seaweed inundation.

Currently, most municipalities tackle this problem by using bulldozers onto their beaches to scoop up the water-filled seaweed (80% water), loading the heavy seaweed unto trucks, and bringing it to landfill – out of sight of tourists, and at considerable costs and usually sand erosion.

Entrepreneurs are stepping up to reuse the dried seaweed from creating new food products, for fertilizer and animal feed. It is even being used for composting, among other ideas, but the market is fairly small, and certainly not for 20 million tons of it.

This blog entry provides a high-level overview of the SSwd beach cleanup process for municipalities. There are 4 stages – all of them contribute to the current high costs and effort required: Collecting; Transporting; Drying; and Disposing. At the end of the blog, I also provide a plausible future scenario using the Frontline Waste JF System.


  • Bulldoze or Bulldozer to Truck: Usually at sunrise before tourists arrive, bulldozers arrive at a beach. Sometimes, the seaweed is mixed into the sand and covered with a fresh layer of sand. Other times, the bulldozer picks up the seaweed, including unwanted sand, and places both into a truck for removal.

Using Specialty Pick Up Machine to Truck: There are a number of companies that have recently built equipment that can “harvest” the SSwd either on the water or at the beach, itself. Products like “The Surf Rake” and “The Ocean Cleaner” have in the last few years started to gain marketplace traction among municipalities that realize the high costs of using bulldozers was palatable when there was less seaweed and it was more seasonal.


Sswd is about 80% water. For each ton of seaweed, 2000 pounds, that’s the equivalent of about 200 gallons of water that needs to be transported. Not only is the seaweed bulky, it’s incredibly heavy, too, and will require many more trucks if loaded right from the water or soon after arriving on a beach.


There are a few options to dry the seaweed currently – evaporation or dewatering or doing nothing. Each of them has deficiencies.

  • The Sun: The easiest and cheapest way is to let the sun dry the seaweed near where collected, if possible as that would lower transportation costs, too. Two big detractors dominate this option: it requires a lot of land to lay out tons of the seaweed, and drying seaweed is also rotting seaweed that stinks. Proper drying can take anywhere from 2 days to a week depending on the humidity and sunshine.

Drying Unit: One can bring the seaweed into a drying unit to quicken the evaporation process. These exist, but the big problem is the amount of energy it takes to run these units to heat the water to hasten evaporation. It has proven to be not very economical.

  • No Drying: This is likely the option of most municipalities who bring the seaweed from truck directly to landfill. The quickest and easiest way is to just add it to the landfill waste mix “as is.” Thus, the seaweed takes up much more space initially, not to mention eventually how this water will eventually seep into the ground as toxic leachate.


  • Hide It: The collected SSwd is brought to a nearby area by truck, out of sight of tourists, and dumped on the ground. There is no drying process. No formal disposal processing. Ex. Galveston Island, Texas

Landfill: The collected SSwd is sent by truck, where possible, to a modern lined landfill capable of capturing/processing the methane that SSwd will create. If such a landfill is too far away, the SSwd will be sent to the nearest landfill.

  • Anaerobic Digestion: The collected SSwd is trucked to a waste facility’s anaerobic digestor and turned into syngas for sale. Theoretically, AD is very promising, but research articles (see below) cite the need for a consistent year-round quantity (and SSwd is seasonal), the high costs to dry and store, and, at end of process, the fact that both quantity and quality of the gas disappoints as sargassum seaweed has lower biomethane potential than most seaweeds. Thus, AD is currently an unattractive investment and unprofitable solution.

Pyrolysis: Pyrolysis requires the intake of dried sargassum seaweed, which is very costly, as well as a steady supply year around –both problematic for profitability. Biochar, bio-oil and syngas are the outputs.


What distinguishes our JF System as a viable solution are twofold:

  1. Using its own generated electricity, we have a proprietary drying system that first uses a Drying Belt to squeeze much of the moisture out, and then brings the drying sargassum through our normal drying system. The result is bone-dry sargassum, now only about 20% of its previous weight.
  2. Our system has multiple auger pipes, and, with a short downtime, each of these retort pipes can be repurposed for MSW or other types of biomass and can therefore operate all year long to create the amount of fuel needed for profitability, high ROI and a much shorter payback period.

It should also be noted: We also have the ability to add high-quality non-recyclable plastics to the mix to increase the quality of fuel, if necessary.

In summary, the Frontline Waste JF System could become best practice and turn SSwd from a cost center and tourism scourge into a revenue center for participating municipalities.

Rob Steir is a business developer and a partner at Frontline Waste.


Swamped by Sargassum: The New Normal for Caribbean Beaches | The Scientist, July 5 2019

Scientists discover the world's biggest seaweed patch. They say it could be the 'new normal' | NBC News, July 9 2019

Miami Beach wrestles with a new and unwelcome visitor: Seaweed - foul piles of it | Miami Herald, June 20 2019


Harvey, Patricia & Milledge, John (2016) | Ensilage and anaerobic digestion of Sargassum muticum

Harvey, Patricia & Milledge, John (2016) | Golden Tides: Problem or Golden Opportunity? The Valorisation of Sargassum from Beach Inundations

Dutch Caribbean Nature Alliance (2019) | Prevention and clean-up of Sargassum in the Dutch Caribbean


The Ocean Cleaner

The Surf Rake


Sargassum seaweed in Placencia, Belize by The San Pedro Sun Newspaper via The Guardian