Communities innovate to address Sargassum seaweed on coasts of Saint Lucia
Sargassum is free-floating brown macro-algae that lives in the temperate and tropical oceans of the world. In the open ocean, the floating seaweed provides important ecosystem services by acting as habitats for a diverse group of marine animals. It provides food, shade, and shelter to many types of specialized fish, crustaceans, and turtles. When it reaches the coastline, it provides fertilizer for the plant ecosystems that protect the shoreline from erosion and promotes biodiversity of marine bird and wildlife.
Since 2011, excessively large quantities of Sargassum have accumulated in the Caribbean Sea, only to wash ashore in several Caribbean countries. Massive Sargassum seaweed blooms are becoming increasingly frequent in the Caribbean. The seaweed covers the beaches in huge, stinking blankets that sometimes measure up to 10 feet in depth. As it rots, the seaweed emits a toxic gas known as hydrogen sulphide, which smells of rotting eggs.
The seaweed creates an extreme lack of oxygen in the sea close to shore, killing off native species and resulting in dead zones by first robbing the water of nutrients before they die and absorbing oxygen out of the water to decompose. It fouls the beaches, not just for the visiting tourists who contribute to the local economies, but also for several endangered species of marine turtles. The turtles have to dig through several feet of seaweed to lay their eggs or climb beyond the seaweed mats to find clear sand. Later, their hatchlings get entangled in the seaweed on their way to the ocean and die.
On the east coast of Saint Lucia, a local youth by the name of Johanan Dujon noticed how the piles of seaweed were causing trouble for the local fishermen by damaging their equipment and boat engines, as well as complicating their daily lives by making landing difficult upon return from fishing trips. The budding entrepreneur recognized an opportunity to capitalize on this freely available resource to create valuable organic agricultural inputs, which could in turn reduce and eventually replace the environmentally harmful synthetic chemicals used to grow food in St. Lucia. In 2014, Dujon founded Algas Organics and began experimentation with formulations to make this idea a reality.
Read more at: Global Environment Facility