Those of us who have sailed across the North Atlantic, particularly on the route from the Canary Islands to the Caribbean, and the route from Bermuda to the Azores, will have seen our share of Sargasso weed or Sagassum floating out there. In fact, we used to look for it because there was a fair chance that a Mahi Mahi or a Wahoo would be hanging out under the weed patch and might be ready to chase a trolled lure.
But since 2011, the amount of Sagassum in the North Atlantic has expanded dramatically fed, largely, by nutrients flowing from the Amazon due to deforestation and modern agriculture in the river’s watershed. The bloom is so vast this year that it has earned the name The Great Atlantic Sagassum Belt that stretches from the Cape Verde Islands all the way west to the Caribbean and the Gulf of Mexico. The weed piles up on Caribbean beaches where it rots in the sun and is, thus, a huge deterrent to tourism.
It also is a real hazard to yachts making the passage west in the trade winds to the Caribbean. Sagassum can get tangled in propellers; it can get lodged in an engine’s raw water intake; and, it can impede your forward progress. For those planning to sail this route in the coming fall season, attention to the position of the Great Atlantic Sargassum Belt will be an important aspect of route planning. Once in the Caribbean, finding islands that are not plagued with and reeking from rotting weed will be the next challenge. Check out this excellent write up from the Yale School of Forestry & Environmental Studies.
https://e360.yale.edu/digest/a-massive-seaweed-bloom-now-stretches-across-the-atlantic-ocean
