Human-caused mortality and injury of NMFS-managed Alaska marine mammal stocks 2013-2017

Section 117 of the Marine Mammal Protection Act (MMPA) requires the National Marine Fisheries Service (NMFS) to estimate human-caused marine mammal mortality and serious injury. Data from documented interactions between human activities and pinnipeds or cetaceans belonging to stocks which appear in the Alaska Marine Mammal Stock Assessment Reports (SARs) were compiled for the 5-year period from 2013 through 2017. A total of 922 unique interactions with evidence of human-caused mortality or injury are summarized in this report. Details for all reported human-marine mammal interactions (approximately 3,500) were first assessed for evidence of human-caused injury or mortality to the marine mammal; injuries and mortalities that could not be attributed with high confidence to human causes were excluded from further analysis. Injury severity determinations were then made for those injuries considered to be human-caused with high confidence. Injury determination details, including the injury source, type, severity, and criteria supporting the determination are presented in the appendices. Records of human-caused mortality are also included in this report and assigned to source. Mortality and injury values were assigned to each interaction for comparison with the potential biological removal (PBR) levels for each stock calculated under the MMPA and appearing within the Alaska SARs. The mortality and serious injury values included in this report are derived solely from documented interactions. Not all human-caused mortality and serious injury to marine mammals is documented, so this report represents a minimum count of human-caused mortality and serious injury to Alaska marine mammal stocks.