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Sargassum was first seen in any quantity in 2014, and a huge issue in 2015. This year, not so much.
See
http://everythingplayadelcarmen.com/...er-of-seaweed/
Reports 6 of 100, 20 of 100 in the worst areas this month.
Update: We have gone up and down the coast a little and as of July 17, 2017 we are at about a 6 out of a 100 for seaweed. We have had calm seas lately. The seaweed from Cancun to Akumal has been very light and really nothing anyone has to worry about. Tulum has a little bit more, but only a 20 out of 100. We also took a boat around the north end of the peninsula and saw only a few small patches of seaweed. These are all good signs for low amounts hitting the beaches.
SEAS isn't very up to dare (10 July) but seems to indicate little problem.