Sargassum is a brown, macroalgal seaweed that is a natural component of Subtropical marine ecosystems. Its structure includes leafy and cystic components which keep it afloat in the sea; when sections of the seaweed decay, they sink to the sea floor. Floating masses of sargassum offer food and shelter for a wide variety of marine creatures (from crustaceans to sea turtles) and the decaying seaweed, having trapped carbon from the atmosphere, feeds organisms from the surface to the sea floor as it sinks.
These natural benefits of sargassum have been overshadowed by its excessive growth in recent decades, likely fueled by pollutants from river water (primarily fertilizers and industrial waste). While parcels of the Sargassum Sea (in the Mid Atlantic) have always broken off and moved ashore on ocean currents, the massive expansion of this seaweed has now produced a 5000-mile long belt of sargassum islands, floating toward the Caribbean and Gulf of Mexico. Wreaking havoc on beaches and reefs, this man-made crisis is threatening both coastal ecosystems and the tourist industry.
As with the Red Tide, our careless stewardship of the planet has turned a natural process into a recurring disaster. Unfortunately, there is no immediate solution to this environmental tragedy; even if pollution was halted today, the damage has been done and will likely worsen as the oceans continue to warm. Efforts to corral the sargassum as a carbon-capture mechanism appears to be the only potential benefit of this ecologic dilemma.
