Protecting Hawaii's False Killer Whales

UPDATE: False Killer Whale Main Hawaiian Island insular population listed as an Endangered Species

On November 12, 2012, National Marine Fisheries Service officially announced that the Hawai'i inuslar population of False Killer Whales was to be listed as an Endangered Species.


False Killer Whale

False killer whales are marine mammals that have a life span similar to that of humans. They form long-lasting relationships and are known to engage in a fascinating sharing ritual of passing a caught fish between the members of their group before consuming it.

Hawaii is home to a genetically unique population of false killer whales, known to scientists as Hawaiian insular false killer whales.(The word "insular" means "of an island or pertaining to an island.")  Fewer than 123 are believed to be alive today  -- and it's estimated that only 46 are capable of breeding. This population is very close to extinction.


  • False killer whales (Pseudorca crassidens) are actually not whales; they are the 4th largest member of the oceanic dolphin family. These animals can weigh approximately 1,500 pounds at adulthood.
  • False Killer Whales are gregarious and form strong social bonds. They are usually found in groups of ten to twenty that belong to much larger groups of up to 40 individuals in Hawaii and 100 individuals elsewhere.
  • False killer whales are found in tropical to temperate waters around the world. Three populations of false killer whales have been identified in the central Pacific – the Hawaii insular, Hawaii pelagic and Palmyra Atoll stocks.
  • Hawaiian insular false killer whales are a distinct population that lives around the Hawaiian islands, in an area ranging up to 70 miles from the islands. They have marked differences in their genetic characteristics from other false killer whales, different behaviors and different “cultural” patterns, including how and where they locate prey. This population spends its entire life around the Hawaiian islands.
  • There are fewer than 123 Hawaiian insular false killer whales alive today  -- and it's believed that only 46 are capable of breeding. When you consider that a mature female false killer whale gives birth only once every 2 to 4 years on average, their current numbers are almost too small to sustain a population. 


  • False killer whales feed on tuna, mahi mahi, wahoo (ono), and other large, deep-water fish. These fish are also targeted by Hawaii’s longline fisheries.
  • Longlining features a long horizontal line that can stretch up to 50 miles long. Shorter lines dangle from the “long line” at spaced intervals. These shorter lines hold bait hooks, which attract fish.
  • False killer whales have learned to steal bait, as well as bite off hooked fish, from the miles of hooks set out by Hawaii’s longline fishing boats. But these “easy” meals come with risk: false killer whales get snagged or entangled, and can die or become injured.
  • Between 1997 and 2009, 43 false killer whales were hooked or entangled with longline fishing gear in Hawaii. Of the 43, three died. False killer whale bycatch in Hawaii has exceeded “sustainable levels” since at least 1999, meaning that these animals are being killed at a rate that’s higher than what the population can sustain. 
  • Longline fishers can take steps such as using circular hooks or weaker hooks, to protect false killer whales and other marine mammals.
  • With the depletion of many fish species due to overfishing, false killer whales are struggling to find food in general. There are fewer fish to hunt, and the ones that are found are smaller than in the past. The fish they consume contain organochlorines (PCBs and PBDEs) and other contaminants that threaten these animals and people alike. Because false killer whales are top level predators, their bodies accumulate PCBs and other toxins, putting them at a greater risk of infection and disease. They need every protection that we can provide them -- right now.


  • Owing to its extremely small population size, as well as a range limited to the Hawaiian Islands, the Natural Resource Defense Council petitioned to list the Hawaiian insular population of FKWs as Endangered under the Endangered Species Act in 2009. 
  • In August 2010, National Marine Fisheries Service (NMFS) released a final “Status Review”, concluding that the population was both a distinct population segment, and at a “high risk of extinction”. 
  • On November 17, 2010, NMFS officially proposed to list the HI FKW DPS as “Endangered”, and under Federal regulations, had one year (November 2011) to make a final ruling on the proposal. 
  •  Pacific Whale Foundation testified on its behalf at a NMFS hearing in Honolulu and also submitted written testimony, as well as hundreds of petition signatures. We thank all of our members and supporters who also submitted testimony in support of this proposal.
  • Despite the November 2011 statutory deadline, NMFS had yet to make a final ruling.  In March 2012, NRDC thus sued NMFS for their failure to meet this deadline. 
  • On November 21, 2012, NMFS released a Final Rule, announcing that Hawaii's insular population False Killer Whales was to be listed as an Endangered Species