Oil Threatens Gulf’s Sargassum

The Gulf of Mexico’s sargassum, known locally as Gulfweed, is a marine seaweed that floats at the surface, providing vital nursery grounds for much of the marine life of these waters. The Gulf’s sargassum sea is the second largest on Earth after the Sargasso Sea, which circulates in the center of the North Atlantic Gyre. This video and article from the Mobile Press-Register tells the story of sargassum, and its terrible vulnerability to oil.

The floating seaweed amounts to the most ephemeral of the Gulf’s aquatic habitats, gathering in patches that range from the size of a backyard pool to swaths measured in hundreds of acres. It drifts at the mercy of wind and tides and collects along the offshore rip lines where different currents meet. Sometimes, it gets pushed ashore, where it rots and stinks, upsetting beachgoers. The same forces that push sargassum patches around in the Gulf are now pushing oil slicks and emulsified goop the consistency of Hershey’s syrup. It is inevitable that the two will meet. When they do, scientists say, the sargassum will die.

A day in the sargassum


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  • Julia Whitty is the environmental correspondent for Mother Jones. Her latest book is Deep Blue Home: An Intimate Ecology of Our Wild Ocean. For more of her stories, click here.