As a red tide event stretched more than 200km from Rio de Janeiro’s coastline late last year, lasting more than eight weeks, it colored the light blue waters a dark reddish-brown , which chased bathers on the coast of Arraial do Cabo. In the high tides of Praia Vermelha beach, dead jellyfish were observed, assumed by bathers to be related to the effects of the red tide.
But were they? The IAEA enabled Brazilian scientists to help authorities answer this question and adopt strategies to monitor, mitigate and protect coastal and marine environments affected by natural disasters, including red tides or harmful algal blooms. (HAB). They were able to put their finger on the presence of various species of microalgae at the origin of red tides throughout the months of November and December.
In response to the emergency, the IAEA provided equipment and trained Brazilian specialists in the use of radioisotopes and stable isotopes and related nuclear techniques through its technical cooperation program. The Fluminense Federal University of Niterói has been equipped with targeted isotopic and nuclear equipment, and its staff has been trained in advanced analytical technologies, such as X-ray fluorescence and elemental and stable isotopic fingerprinting techniques.
“The training and equipment provided helps Brazilian experts identify triggers and monitor HABs more effectively,” said Dominika Zahrer, IAEA program management officer who coordinates activities with Brazil. The origins of the cooperation date back to the 2015 collapse of the Fundão tailings dam in Mariana, the oldest town in the state of Minas Gerais, and the disaster devastated two villages, leaving 19 people dead and around 200 houses destroyed, she added. .
This support made it possible to characterize and determine the composition of the materials and to assess pollution by heavy metals in the impacted estuarine sediments. This allowed Brazilian experts to assess the impact of the Fundão tailings dam burst on coastal and marine environments to help monitor, protect and restore these environments. Their knowledge and equipment have come in handy many times since then, most notably during last year’s red tide.