Sargassum Decimates Loggerhead Turtle Nests on Costa Maya Beaches

Mahahual, Quintana Roo — Sargassum has devastated loggerhead sea turtle nesting on the Costa Maya, environmental groups say, with one beach recording just three nests this season compared with 45 to 50 in previous years.

Since April, only 120 loggerhead nests have been documented in the area, while green and white turtle species have registered 280 nests — more than double, according to conservation organizations.

At Xooch beach, only three loggerhead nests have been counted for the current season. In past years, the average for this time of year was between 45 and 50.

Víctor Rosales, a representative of the group Proyecto Aak Mahahual, said that while both loggerhead and green turtles are classified as endangered, the green turtle population remains relatively healthy. Loggerheads, he said, face serious difficulties because they tend to nest close to the waterline. Erosion, sargassum accumulation and the loss of beach have left them very little surface area to deposit their eggs. Green turtles, by contrast, climb to the coastal dune, where they can find higher, more suitable nesting spots.

Rosales said this season has presented the most obstacles for these marine species in the past 16 years. He cited the case of a 180-kilogram green turtle whose body washed ashore at Playa Chaac Chí.

The excessive buildup of sargassum is displacing turtles toward rocky beaches or, as has been documented, forcing them to lay their eggs in the sea, Rosales added.

Environmentalist Marco Castilla said the drop in nest numbers is alarming, noting that only 90 percent of hatchlings that emerge on the coastal dune have a chance of survival. Sargassum creates a double problem, he said: it acts as a barrier preventing adult turtles from reaching the beach, and it also blocks hatchlings from making their way to the sea.

According to the Quintana Roo Environment Secretariat, 12,890 tons of sargassum have been collected in Mahahual, part of a state-wide total of 114,071 tons.