Dear MARMAM community, My co-authors and I are pleased to announce and share our new paper: “The Southern Ocean Exchange: porous boundaries between humpback whale breeding populations in southern polar waters”, which has been published in *Scientific Reports.* Abstract: Humpback whales (*Megaptera novaeangliae*) are a cosmopolitan species and perform long annual migrations between low-latitude breeding areas and high-latitude feeding areas. Their breeding populations appear to be spatially and genetically segregated due to long-term, maternally inherited fidelity to natal breeding areas. In the Southern Hemisphere, some humpback whale breeding populations mix in Southern Ocean waters in summer, but very little movement between Pacific and Atlantic waters has been identified to date, suggesting these waters constituted an oceanic boundary between genetically distinct populations. Here, we present new evidence of summer co-occurrence in the West Antarctic Peninsula feeding area of two recovering humpback whale breeding populations from the Atlantic (Brazil) and Pacific (Central and South America). As humpback whale populations recover, observations like this point to the need to revise our perceptions of boundaries between stocks, particularly on high latitude feeding grounds. We suggest that this “Southern Ocean Exchange” may become more frequent as populations recover from commercial whaling and climate change modifies environmental dynamics and humpback whale prey availability. Please find it freely available online at www.nature.com/articles/ s41598-021-02612-5 On behalf of my co-authors, I thank you for the interest in our research. Renata Renata S. Sousa-Lima, MSc, PhD Professora Associada em Comportamento Animal / *Associate **Professor of **Animal Behavior* *Bolsista de Produtividade CNPq 2* *ORCID *https://orcid.org/0000-0002-2638-1695 Lattes http://lattes.cnpq.br/1514389007687960 LaB - Laboratório de Bioacústica / *LaB - Laboratory of Bioacoustics* *www.LaB.bio.br <http://www.LaB.bio.br>* Departamento de Fisiologia e Comportamento / *Department of Physiology & Behavior* Centro de Biociências / *Biosciences Center* Universidade Federal do Rio Grande do Norte / *Federal University of Rio Grande do Norte* Natal, RN - Brasil 59078-970 Tel.: + 55 (84) 3215 3409 - 3215 3410 - 3215 3411 Fax: + 55 (84) 3211 9206 sousalima.renata@gmail.com "Be kind, for everyone you meet is fighting a great battle." Philo of Alexandria