Dear MARMAM community, On behalf of my co-authors, I am pleased to share our recent publication in the Journal of the Acoustical Society of America: Dana A. Cusano, David Wiley, Julia M. Zeh, Iain Kerr, Alicia Pensarosa, Chris Zadra, K. Alex Shorter, Susan E. Parks; Acoustic recording tags provide insight into the springtime acoustic behavior of sei whales in Massachusetts Bay. J. Acoust. Soc. Am.; 154 (6): 3543–3555. The paper is Open Access and available to download here: https://doi.org/10.1121/10.0022570 Abstract The acoustic ecology of sei whales (*Balaenoptera borealis*) is poorly understood due to limited direct observation of the behavioral context of sound production and individual behavior. Suction cup–attached acoustic recording tags were deployed on sei whales to unambiguously assign call types and explore the acoustic behavior of this endangered species. Twelve tag deployments resulted in ∼173 h of acoustic data and 1030 calls. Sound types included *downsweeps* and three previously undescribed call types. *Knocks* were short duration (<1 s), with an average peak frequency of 330 Hz. *Pulse type 1* and *pulse type 2 calls*, typically produced in sequences, were short in duration (0.08 and 0.28 s) and low in average peak frequency (50 and 26 Hz), with relatively high received levels. Average call rates for all call types combined were three calls per hour, but increased during twilight. Sex differences in call type usage included a higher use of *pulses* by females and *knocks* by males. Calls were almost exclusively produced at depths <10 m, although whales rarely dove deeper in this study. These data provide a more comprehensive picture of the acoustic and behavioral ecology of sei whales than previously possible, which can inform future conservation efforts for this endangered species. Please feel free to contact me with any questions at danacusano@gmail.com. Thanks, Dana Cusano, PhD National Post Doctorate Fellow, National Marine Sanctuary Foundation Sponsored Associate, Syracuse University