There is sargassum in Mazatlan but it is not dangerous

For the Pacific coast of Mexico, there is a record of 42 seaweed species, of which only one inhabits Mazatlan and its name is Sargassum liebmanni. Sargassum is found in the rocky area next to the house of the Marino, it is a small plant about 10 centimeters high that appears with little biomass between November and February, but then disappears, therefore, it is considered part of the ecosystem.

The species Sargassum muticum is an Asian species native to Japan that has invaded the Pacific coast, from Vancouver, Canada, to Magdalena Island in Baja California Sur. It is believed that it entered the seeds of the oyster Crassostrea gigas, imported from Japan in 1940, since then it has invaded 4,300 kilometers of Pacific coasts. It lives from the intertidal zone to about 20 meters deep.

There is no danger because they are there forming part of the ecosystem and nothing happens. Here there is a kind of seaweed in the Casa del Marino, there is a rocky promontory, there is sargassum, but it appears and disappears in that piece of rock, small and does not pass from there, there are species that can go unnoticed, the difference is that these are benthic and do not pass from there.

The difference between benthic algae and the sargasso that affects the Gulf of Mexico is that the former live attached to a rocky substrate and do not have so much light because they are at the bottom of the sea, while the latter float, get nutrients from the sea and the light hits them directly, which makes them reproduce in abundance.

Concerning the sargassum in the Gulf of Mexico serge, its origin is not yet known, although it is believed to come from Brazil due to the high discharge of nutrients in that region; however, these macroalgae have always existed in that area, and as an example on can cite the Sea of the Sargasso, as documented in the chronicles of Christopher Columbus.

It has always been there, it has a great advantage because it lives on the surface of the water, gets light directly, and has nutrients; while the ones on the coasts of the Gulf of California and Mazatlan, live on the bottom and do not get enough light, are more limited in light and their growth is slowing.

This does not rule out the risks that one day the floating sargassum will reach the Pacific coast, but its probability is minimal, because although it will cross from the Atlantic to the Pacific, the waters here are more turbid and dense, which would slow down its reproduction.

"It is not a law that we are not going to get there, but it is not visualized, the only part that I see that can pass through is the Panama Canal, that some boat accidentally brought it into a compartment, that would be the only possibility, but for reasons of currents I do not believe; on the other hand, the waters that we have here are very turbid, in the water column they are stacked, it would cost them more work to get the light," said the specialist Julia Ochoa Izaguirre.

So far there are only predictive models about the origin of sargasso in the Gulf of Mexico, which affects the beach areas of Quintana Roo. "They don't know, they're doing some predictive models and they say it's probably Brazil's coastline because of the Amazon that gets so many nutrients, but it's not yet proven, they would have to do more specific studies," she said.

One of the ways to know the origin of the algae is through isotopic nitrogen, with procedures that allow us to characterize the isotopes of the algae's nitrogen and compare it with the source of the Amazon's water, to see if it comes from that place. It characterizes what is in the algae of that nitrogen and if you characterize the source of water from the Amazon, with that you can see where it comes from and have not done that study, depending on who is researching, that type of analysis can discover where it comes from. In this way, the 40 species of these macroalgae found in the Gulf of California were identified, two of which are in Mazatlan and come from Japan and the Asian continent.