For the second time in three years, Yucatán is facing a coastal red tide. This week, marine fauna that suffocated to death washed ashore on the Chuburná seashore.
Like ocean currents, the tide moves from east to west; the port west of Chuburná moves toward Sisal.
We cannot give a figure for how long a red tide lasts because they have been highly variable in Yucatán. Red tides have lasted from two weeks to more than five months, reports Dr. Jorge Herrera Silveira, head of the Primary Production Laboratory at the Center for Research and Advanced Studies (Cinvestav) in Mérida.
As examples, Dr. Herrera Silveira mentions that the 2022 red tide lasted about two weeks, and the 2011 red tide lasted about five months, from June to almost November.
Since July, Cinvestav-Mérida has reported the presence of a red tide (its technical name is Harmful Algal Blooms (HAB)) in Yucatán, based on the results of four samples of seawater and algae taken on July 8, 10 and 12 km off the coast of Telchac and Dzilam de Bravo; on July 15 and August 1, 20 km north of Progreso; and on August 8 in a strip parallel to the coast of Chicxulub-Chuburná, both municipalities in Progreso.
In each results report, Cinvestav includes images of the sampling efforts, the dominant phytoplankton species, the sites where the samples were collected, and the area where the red tide is located. For example, the day before yesterday, when announcing the results of the August 8 sampling, it reported that a satellite image “confirms that the HAB patch is located between the ports of Chelem and Chuburná.”
For its part, the Yucatán Ministry of Health (SSY) reported on July 10 that the Interinstitutional Committee for Monitoring and Evaluation of Red Tide was monitoring the presence of microalgae on the coast. On July 23, it reported “no signs of a red tide.” On August 7, it reported that the Committee “rules out the presence of a red tide in Yucatán.” And just on Tuesday, August 12, it reported that the Committee decided to “officially declare a red tide event in the coastal region from Progreso to Celestún.”
Unlike Cinvestav, the SSY does not publish images or maps. Furthermore, only in two of its four reports did it identify the species of microalgae detected, but it did not specify abundance figures, that is, how many cells per liter the State Public Health Laboratory found.
In Celestún, CINVESTAV has never reported a red tide event in its 24 years of monitoring, nor Sisal; its sampling of the Maximum HABs has reached Chuburná.
“Precisely now, since we have colleagues from the UNAM Unit in Sisal and we also know fishermen, we are waiting for them to tell us what they are observing; so far, they have not seen water the color it is in Chuburná and Chelem,” said Dr. Herrera Silveira.
“With certainty, with the data from Cinvestav’s coastal sampling, we can only say that the HAB, which is the technical name for the red tide, is now a patch between Chelem and Chuburná,” the expert continued.
Finally, regarding how long the effects of the current red tide would last, Dr. Herrera Silveira answers that new sampling is also needed to monitor the evolution of the HAB.
As an example, he mentions that the 2022 red tide lasted two weeks, and the most intense economic impacts were recorded in Telchac, in fishing and tourism, according to a master’s thesis currently in progress.
Source: yucatan.com.mx
