Dear colleagues , My co-authors and I are pleased to share our new publication in Marine Mammal Science. Rafael R.Carvalho, Carlos Eduardo P. Quintana, Carlos ViniciusC. dos Santos, Elitieri B. Santos-Neto, LisBittencourt, Karina S. Pereira, Tatiana L. Bisi,Maja Kajin, Jose Lailson-Brito Jr., Alexandre F.Azevedo. Abundance of two Guiana dolphin (Sotalia guianensis) populations inhabiting adjacent areas insoutheastern Brazil. Marine Mammal Science. Early View https://doi.org/10.1111/mms.13188 Abstract Guiana dolphins (Sotalia guianensis) are commonly found inshallow waters from South and Central America. FromMarch 2018 to June 2019, boat surveys were conducted tomonitor two populations inhabiting the adjacent waters ofIlha Grande Bay and Sepetiba Bay to estimate populationabundances and population parameters of apparent survivaland capture probability. Photo-identification was used as amark-recapture technique. A total of 672 dolphins was cataloged in Ilha Grande Bay and 826 in Sepetiba Bay, withtwo individuals being photographed in both areas. Population parameters were estimated through mark-recapturemodels and total population abundance was estimated at1,949 and 1,560 individuals in Ilha Grande Bay and SepetibaBay, respectively. Seasonal estimates were modeled showing that the Sepetiba Bay population may have stronger sitefidelity to the study area than individuals in Ilha GrandeBay. Apparent survival was estimated in a mixed modelframework avoiding bias due to the large presence of transient individuals. The estimates presented here are a resultof an effort conducted months after an unusual mortalityevent linked to Guiana dolphin cetacean morbillivirus andour findings indicated that surviving individuals did not have long-term deadlyeffects, but continuous efforts should be considered for a long-term evaluation.  Feel free to contact me at carvalho.ramos@yahoo.com.br if you have any inquiries. Kind regards, Rafael Carvalho --  BiólogoDoutor em Ecologia e Evolução-PPGEE/UERJ Laboratório de Mamíferos Aquáticos e Bioindicadores "Izabel Gurgel" - MAQUA Faculdade de Oceanografia Universidade do Estado do Rio de Janeiro - UERJ  tel.: (21) 2334-0065 / 2334-0795 cel.: (21) 99802-3536http://lattes.cnpq.br/6546679825444246