Playa del Carmen keeps its beaches clean from seaweed
In order to minimize the impact of the seaweed recharge, Playa del Carmen focuses on three main areas: the collection of sargassum in line with the beaches, the installation of a 2.5 km retaining and redirecting barrier, as well as the two harvester barges with a minimum capacity of 200 tons per day, which are assisted by two barges that take the collected algae to the collection points.
The above was reported by the director of the Federal Maritime Land Zone, Marco Loeza Pacheco, noting that as a result of this strategy, 50 tons per day of sargassum are collected and placed on the shores of Playa del Carmen through the staff and the barges, totaling 8,258 tons removed from the beach area in the period from January to date.
The work in the coastal area is carried out by 90 workers who remove the seaweed manually supported by tools and light machinery, properly equipped and maintaining a healthy distance, which works from 6 in the morning to 5 in the afternoon.
To reinforce this work, the containment barrier was placed, in addition to the boats that harvest the seaweed in shallow waters and are operating at 100%, which are being supported by two barges. In the last week when the second atypical arrival of 400 tons in a single day took place, it was timely attended and the sandbanks were cleaned.
Sargassum comes from Africa and reaches the part of the Amazon where it begins to nourish, rapidly increasing its volume, and then continue advancing until it reaches the beaches of Quintana Roo.
The seaweed problem is not exclusive to the state, it is a natural phenomenon present in several parts of the world and even in several areas its arrival is greater, however, it can be emphasized that no one has achieved as much progress as Mexico in the fight against this macroalgae.
The Sargasso Monitoring Network publishes daily on Facebook how to find all the beaches in the state regarding the arrival of the sargassum.
Sargasso can be harmful to humans
Sargassum, which has been arriving massively in the Mexican Caribbean since 2014, contains arsenic, copper, manganese, and molybdenum, substances that in high concentrations are harmful to humans and wildlife, said Rosa Elisa Rodríguez Martínez, a researcher at the UNAM Institute of Marine Sciences and Limnology.
A study of 63 samples of the macroalgae also found aluminum, calcium, chlorine, copper, iron, potassium, magnesium, phosphorus, lead, rubidium, sulfur, silicon, strontium, thorium, uranium, vanadium and zinc, among others.
"While some of these elements are essential nutrients, others can be toxic. The one of greatest concern is arsenic, because it was detected in all the samples collected, and in most of the tests it exceeds the maximum permitted limits," she said.
The sargassum began to arrive on the coast of Quintana Roo in late 2014, which intensified in 2015, and by 2018 the volume was exaggerated to continue until September 2019.
The expert from the Academic Unit of Reef Systems, based in Puerto Morelos, warned that in the last four years millions of tons arrived, and very few were removed; their accumulation and decomposition severely affect coastal ecosystems, beaches, coral reefs, seagrasses, mangroves and possibly the aquifer, which is the only source of freshwater in the region.
"Since 2015 we have begun to see the mortality of seaweed stuck to the coast, due to a large amount of organic matter and bacterial activity resulting from the decomposition of these algae, which by the action of the waves return to the sea turning it brown, clouding the water, reducing the amount of oxygen and light, and increasing the levels of sulfur, nitrate, and ammonia. This deterioration in water quality results in the plants not being able to carry out photosynthesis and dying," she explained.
In 2018, the mortality of marine fauna like fish, crustaceans, and mollusks began to be recorded. Also the deterioration of corals, as a result of an epidemic called "white syndrome", and although it is not proven that it is associated with sargassum, "we know that the low quality of the water contributes to the death of these organisms.
Considering the results obtained, Rosa Elisa Rodríguez Martínez recommended analyzing the accumulation of toxic elements in sargassum before using it in the food and pharmaceutical industry, or avoiding its use.
"It is necessary to find adequate ways to manage it, so that it does not deteriorate our beaches or other coastal ecosystems, as well as the aquifer. Efficient management will also avoid affecting Quintana Roo's economy, because it has impacted tourism due to its bad appearance, bad smell and probable skin irritation," she commented.