Three data sets are included here to aid in assessment of the sea otter population collapse in southwest Alaska. One data set consists of results of sea otter surveys conducted between 1959 and 2015 at Bering Island, Russia and a selection of western Aleutian Islands in Alaska. Sea otter counts are reduced to a comparable value of otters per linear kilometer. Another data set consists per-capita and per kilometer recovery rates of stranded sea otter carcasses from locations ranging from Bering Island, Russia, several Aleutian Islands, sites along the Alaska Peninsula, and Prince William Sound, Alaska. These data are mainly from the period 1991-2009 and are from stable populations as well as those in decline or post decline. The third data set consists of blood chemistry and hematology of sea otters captured from along this same north Pacific region from 2004-2012. This data set can be used to help assess sea otter health in this region. Gene transcription data from some of the subject sea otters can be found at Bowen, L., Ballachey, B. E., Bodkin, J. L., Miles, A. K., Esler, D. and Kloecker, K. A., 2017, Sea Otter Gene Transcription Data from Kodiak, the Alaska Peninsula, and Prince William Sound, Alaska, 2005-2012: U.S. Geological Survey data release, https://doi.org/10.5066/F789141P. These data support the following publication: M. Tim Tinker, James L. Bodkin, Lizabeth Bowen, Brenda Ballachey, Gena Bentall, Alexander Burdin, Heather Coletti, George Esslinger, Brian B. Hatfield, Michael C. Kenner, Kimberly Kloecker, Brenda Konar, A. Keith Miles, Daniel H. Monson, Michael J. Murray, Ben Weitzman and James A. Estes, 2021, Sea otter population collapse in southwest Alaska: assessing ecological covariates, consequences, and causal factors: Ecological Monographs