Injury Determinations for Humpback Whales and Other Cetaceans Reported to NOAA Response Networks in the Hawaiian Islands During 2013–2016

October 23, 2018

A summary of injury determinations for cetaceans in Hawaii reported injured by human causes during 2013–2016

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 made contact with a vessel. Bradford and Lyman (2015) made determinations of injury severity (i.e., serious or non-serious) for cetaceans in Hawaii reported injured by human causes during 2007–2012. Prior to this work, most human-caused injuries reported to PIR-MMRN and HIERN were not accounted for in the mortality and serious injury (M&SI) estimates that are a key component of the Stock Assessment Reports (SARs) for cetaceans in Hawaiian waters. The present paper provides a summary of injury determinations for cetaceans in Hawaii reported injured by human causes during 2013–2016. Injury determinations were made using a nationally standardized process and criteria for distinguishing serious from non-serious injuries (NMFS 2012). From 2013 to 2016, there were 70 reports of cetaceans with human-caused injuries, including 21 humpback whales involved in vessel collisions, 38 humpback whales entangled in presumed or confirmed fishing gear, and 11 other cetaceans hooked or entangled in presumed fishing gear or marine debris. Estimates of M&SI are considered over five-year periods; thus, determinations from 2012 to 2016 are relevant to the 2018 SARs. The 71 humpback whale vessel collisions and entanglements during 2012–2016 led to 37.68 serious injuries and 1 mortality. The resulting average of 7.74 mortalities and serious injuries per year can be considered a minimum estimate of M&SI from Hawaii for use in the 2018 SAR of the central North Pacific stock of humpback whales. For the other cetaceans in 2012–2016, serious injury determinations of relevance to the 2018 SARs were made for a bottlenose dolphin of the Hawaii Island stock, rough-toothed dolphins of the Hawaii stock (n = 2), spinner dolphins of the Hawaii Island (n = 5) and Oahu/4-Islands[1] (n = 2) stocks, and a pantropical spotted dolphin of the Hawaii Island stock. Significantly more effort is needed to report, document, and monitor injured Hawaiian cetaceans other than humpback whales.

 

 

[1] The 4-Islands region comprises the islands of Maui, Molokai, Lanai, and Kahoolawe.

Last updated by Pacific Islands Fisheries Science Center on 06/24/2019

Humpback Whale