Injury determinations for humpback whales and other cetaceans reported to NOAA Response Networks in the Hawaiian Islands during 2018

Reports of cetaceans with human-caused injuries in Hawaiian waters are made each year to the Pacific Islands Region Marine Mammal Response Network (PIR-MMRN, coordinated by the NOAA National Marine Fisheries Service (NMFS) Pacific Islands Regional Office) and the Hawaiian Islands Entanglement Response Network (HIERN, coordinated by the NOAA Hawaiian Islands Humpback Whale National Marine Sanctuary). These injury reports largely involve humpback whales that were entangled in fishing gear or marine debris or were struck by or otherwise injured by contact with a vessel. Bradford and Lyman (2015, 2018, 2019) made determinations of injury severity (i.e., serious or non-serious) for cetaceans in Hawaii reported injured by human causes during 2007–2017. The present report provides a summary of injury determinations for cetaceans in Hawaii reported injured by human causes during 2018. Injury determinations were made using a nationally standardized process and criteria for distinguishing serious from non-serious injuries (NMFS 2012). During 2018, there were 19 reports of cetaceans with human-caused injuries, including 4 humpback whales involved in vessel collisions, 11 humpback whales entangled in presumed fishing gear or marine debris, and 4 other cetaceans with human-caused injuries. The 15 humpback whale vessel collisions and entanglements led to 11 serious injuries. For the other cetaceans, injury determinations of serious were made for two spinner dolphins of the Hawaii Island stock entangled in fishing gear. While accounting for injuries reported to PIR-MMRN and HIERN has improved the stock assessment process for some populations, significantly more effort is needed to report, document, and monitor injured cetaceans in Hawaiian waters, particularly species other than humpback whales.