Dear Colleagues, We regret to inform you of plans for underwater blasting due to commence imminently at Sal-Rei Harbour in Boa Vista, Cape Verde during peak humpback whale breeding season. This is the single most important location known for breeding humpback whales in the Eastern North Atlantic. This population is precariously small (~230 individuals) and genetically distinct. We are urgently contacting government officials requesting that the blasting is postponed until after the breeding season. Only yesterday, a mother/calf pair were observed inside the harbour where the blasting is to occur until August. Your advice and support on this issue would be gratefully appreciated. If you would like to submit a letter to voice your opposition to this activity, we would be happy to provide you with some more information and contact details of appropriate authorities. Best wishes, Conor Ryan (Marine Conservation Research, United Kingdom) Pedro Lopez Suárez (Bios, Sal Rei, Cape Verde) Cornelis Hazevoet (Instituto de Investigação Científica Tropical, Lisboa, Portugal) Frederick Wenzel (National Oceanographic and Atmospheric Administration, USA) Beatrice Jann (Swiss Whale Society, Switzerland) Simon Berrow (Irish Whale and Dolphin Group / Galway-Mayo Institute of Technology, Ireland)