Dear Marmam colleagues, We are pleased to share this recent publication about blast fishing acoustic characterization in Brazil and its potential impact to marine mammal conservation. This work is part of a long term research project on Behavioral ecology of Guiana Dolphins (Sotalia guianensis), an endangered species, in the Todos os Santos Bay, Brazil. During field surveys to study dolphin acoustic behavior, we recorded and described the first underwater explosion reported for Latin America, discussing its potential impact to harm local marine mammals, as the resident S. guianensis population. Melo-Souza, V.; Gavrilov, A.; Rossi-Santos, M.R. Dropping a bombshell: Acoustic characterization of blast fishing in Todos os Santos Bay, Brazil, and its implication for marine conservation. Marine Pollution Bulletin, 202, May 2024, 116332. Blast fishing is an illegal fishing method that not only affects fish populations and the marine ecosystem, but also local food security and local economy. Despite its effects, blast fishing continues to persist in many coastal regions around the world, including Todos os Santos Bay (BTS - Baia de Todos os Santos) in Northeastern Brazil. This study fits into a long term project on Guiana Dolphin (Sotalia guianensis) behavioral ecology and during bioacoustic survey to study dolphin sounds, we registered the first acoustic record of underwater explosions along this region. The results revealed a distinctive underwater acoustic signal detected in the BTS, indicating evidence of blast fishing activities. This Anthropogenic sound is confirmed to be harmful for marine mammals due to its acoustic characteristics, enabling overlapping of dolphin sounds and even physiological damage. The acoustic characterization of blast fishing in BTS provides crucial information on its occurrence and extent of this destructive practice worldwide. PDF is available at the link below: https://authors.elsevier.com/c/1ituz,asi9t0O Best Regards, Marcos Rossi-Santos marcos.rossi@ufrb.edu.br Acoustic Ecology and Animal Behaviour Laboratory Federal University of Recôncavo da Bahia - Brazil