Satellite Images Show the Movement of Floating Sargassum in the Gulf of Mexico and Atlantic Ocean

Abstract

The question of the origin, distribution and fate of the floating seaweed Sargassum has fascinated sailors and scientists from the time of Columbus. Observations from ships are hampered by the large and variable area over which Sargassum is dispersed. Here we use satellite imagery to present the first mapping of the full distribution and movement of the population of Sargassum in the Gulf of Mexico and western Atlantic in the years 2002 to 2008. For the first time, we show a seasonal pattern in which Sargassum originates in the northwest Gulf of Mexico in spring of each year, is advected into the Atlantic in about July, appearing east of Cape Hatteras as a "Sargassum jet", and ending northeast of the Bahamas in February of the following year. This pattern appears consistent with historical surveys. Future satellite observations will show whether this pattern repeats in all or most years.