The Decline of the Hawaiian False Killer Whale Population

The Hawaiian population of the false killer whale is facing a grave threat of extinction, as revealed by a recent study published in the journal Endangered Species Research.

Initially mistaken for a member of the killer whale family due to its similarities in skull structure and behavior, the false killer whale is a large, predatory dolphin that preys on fish like tuna and mahi-mahi. While the species is considered near-threatened on a global scale, the distinct non-migrating population near Hawaii has been classified as endangered since 2012.

Population Decline

With an estimated population of 184 individuals in 2012, researchers now believe that the Hawaiian false killer whale population has dwindled to just 139 by 2022, representing a loss rate of approximately 3.5 percent per year. The decline is attributed to various factors, including entanglement and hooking from interactions with Hawaii’s commercial fisheries.

Threats to Survival

Studies have shown that over a quarter of the population has evidence of surviving prior fisheries interactions, indicating the widespread issue of depredation of bait or catch and regular hooking incidents. Additionally, high levels of bioaccumulated PCBs in the dolphins’ blubber and inbreeding within small social groups have been identified as contributing factors to their decline.

Conservation Concerns

Conservation advocates warn that the slow reproductive rate of female false killer whales, who only give birth once every seven years on average, coupled with the ongoing threats from fisheries interactions, could push the population towards extinction if immediate conservation measures are not implemented by NOAA Fisheries.

The lack of fisheries observers on small nearshore vessels makes it challenging to accurately assess the extent of conflict with fisheries, further underscoring the urgency of proactive conservation efforts to protect these endangered marine mammals.