New call for study of false killer whales around Hawai'i

An apparent crash in the population of false killer whales around the Hawaiian Islands has prompted a call for new research into whay that's happening.

One of the questions is whether and how much fishing is affecting the whales.

(Image: NOAA photo of false killer whales off Hawaii by Robin Baird.)

The Marine Mammal Advisory Committee of the Western Pacific Regional Fishery Management Council met last week in Honolulu and called for a series of studies into whale populations.

Among the reviews recommended: aerial counts, photo identification and genetic work on the population; assessments of the impact of longline and shortline (longlines less than a nautical line in length) fishing on the whales; determining to what degree the whales are impacted by being shot by fishermen and ingesting hooks when they go after bait or hooked fish; getting the Papahanaumokuakea Marine National Monument to study the whales in its waters; and more.

It's generally concluded that the large dolphins known as false killer whales have two distinct populations around Hawai'i. One is a group of several hundred whales that remain around the islands, and the other is the pelagic stock that ranges long distances through the eastern North Pacific.

As far as the National Marine Fisheries Service knows, Hawai'i's longline fleet catches fewer than six animals a year, but there is not enough information on whether that has a significant impact on the local population.

“There is also no data available on the current productivity rate or on the current population trend of the Hawaii stocks. Furthermore, additional injury and mortality of false killer whales is known to occur outside of the EEZ by US and international longline operations, and the potential effect on the Hawaii pelagic stock is unknown,” the fishery council said in a news release.

There are some 6,000 foreign longline ships working the Pacific. About 125 are based in Hawai'i. But additionally, there are many largely unregulated recreational and nearshore shortline fishing boats working from Hawai'i harbors.

There was some information at the meeting, generally anecdotal, that some of the unregulated fishers deliberately shoot false killer whales that come into contact with their fishing gear.
For more information see the fishery council website.

For more information on false killer whales, see this NOAA website, or visit http://www.cascadiaresearch.org/robin/falsekillerwhale.htm.

© Jan TenBruggencate 2009