Plan to Protect Rare False Killer Whales Is Scrutinized After Serious Injuries Spike

False killer whale. Credit: Robin Baird
False killer whale. Credit: Robin Baird

Last year, the Hawai`i deep-set longline fleet interacted with more Hawaiian false killer whales than it had in more than a decade and most of those interactions resulted in serious injuries, according to the National Marine Fisheries Service. This happened despite a Take Reduction Plan (TRP) that required gear changes intended to leave hooked whales with only minor injuries.

The false killer whale take reduction team established by the National Oceanic and Atmospheric Administration (NMFS’ parent agency) meets at the end of this month to discuss the plan it created two years ago. Whether the team will take steps to amend the plan remains to be seen, but at the Western Pacific Fishery Management Council’s meeting last month in Honolulu, team coordinator Nancy Young said it’s too soon to say whether or not the plan is ineffective.

“We don’t have bycatch estimates yet. Effort data is still being processed,” she said. (Bycatch refers to the hooking of animals, such as the false killer whales, that are not intended to be caught; effort refers to the overall number of hooks set by the longline fishing fleet.) She added that because the number of interactions (also called takes) in a given year is so small relative to the total fishing effort, it may be many years before her office determines with certainty if there has been any change in the rate of mortality and serious injury to false killer whales caused by the longline fishing effort.

But while Young and her colleagues at NMFS may have thought it is premature to draw conclusions from limited data, members of the Western Pacific Fisheries Management Council and its Scientific and Statistical Committee had no such compunctions. At the council’s meeting last month, council members followed the lead of the SSC, voting to recommend that NMFS immediately evaluate the effectiveness of the Take Reduction Plan by comparing data pre- and post-TRP.

A Jump in Takes

For the past decade or so, except for 2009 and 2014, the number of documented takes of false killer whales by the deep-set longline fishery in a given year has generally been five or less. Under the TRP, if the fleet kills or seriously injures just a couple of false killer whales within the U.S. exclusive economic zone (EEZ) in a year, a large swath of fishing grounds south of the main Hawaiian islands, known as the southern exclusion zone (SEZ), is closed until the take reduction team can meet and decide on a new course of action, if necessary. Last year, two of the 11 false killer whale takes by the deep-set longline fleet occurred within the EEZ, but only one of them was determined to be a serious injury.

Young raised the possibility that last year, after one false killer whale had been seriously injured inside the EEZ, longliners directed their efforts to international waters, so as to avoid another serious injury determination that could have led to the closure of the SEZ. However, eight of the nine takes that occurred in international waters still resulted in serious injury.

On the other hand, the effort focused on international waters might be “just a continuation of a long-term trend of fishing in the high seas,” she said.

She also suggested that the presence of observers may be affecting where vessels fish. Observers, which document interactions with federally listed threatened or endangered species, are required on only a small fraction – around 20 percent – of deep-set longline vessels. Young said her office is looking into whether vessels that have observers on them are fishing mainly outside the EEZ.

Perhaps because of these possibilities, the fact that so many of last year’s takes occurred outside the EEZ, and that eight of them were serious injuries, Young said that when evaluating the TRP’s effectiveness, the fleet’s impacts both inside and outside the EEZ need to be considered.

Although she said it will take time to determine the overall effectiveness of the TRP, Young acknowledged that the circle hooks the fleet is required to employ are not performing as hoped.

Before the TRP went into effect in 2013, 89 percent of the false killer whales taken suffered serious injuries. Research at the time the plan was being created had suggested that circle hooks could reduce that rate to 50 percent. Since the plan has been in place, however, the serious injury rate has only dipped slightly, to 81 percent.

The NMFS has been able to identify about half of the gear involved in the two dozen or so takes that occurred over the past two years, but it has been unable to determine what hook or line characteristics might lead to a particular injury determination, Young said.

Even though the preferred hooks and lines are being used, they are still resulting in a lot of serious injuries. Young suggested that handling of the whales by vessel captains or crew may be a factor. To address this, the Hawai`i Longline Association, a trade association, recently created a training video for boat captains on how to treat a hooked animal so that it is released without serious injury.

The video, which was played at the council meeting, stressed repeatedly that the animals be released with no gear attached.

“If it is attached, it will be considered mortality or serious injury. Make sure to do your part to straighten the hook. Retain constant tension to the line. Do NOT cut the line,” the video’s narrator stated.

Despite Young’s reluctance to draw conclusions from such limited data, the Western Pacific Fisheries Management Council members followed the recommendations of the council’s Scientific and Statistical Committee, voting to recommend that NMFS immediately evaluate the effectiveness of the TRP by comparing pre- and post-TRP data.

A council press release following the meeting added that NMFS should “explore alternative approaches to mitigate interactions between the Hawai`i deep-set longline fishery for tuna and the pelagic stock of false killer whales as the effectiveness of the current measures may never be analyzed conclusively due to the rate nature of these interactions.”

The release continues that the TRP’s five-year goal is to reduce mortalities and serious injuries to less than 10 percent of the potential biological removal (PBR) level set by NMFS at 9.1 whales per year. (According to the Marine Mammal Protection Act, PBR is the number of whales that can be killed or seriously injured in a given year without jeopardizing the stock.)

“Ten percent of the 9.1 PBR for the pelagic false killer whale is less than one,” council executive director Kitty Simonds said in the release. “The goal of the [Marine Mammal Protection Act] is to reduce mortalities to zero. Only one level of fishing can guarantee a zero level of mortality and that is zero, which is intolerable and formidably stupid considering the rare occurrence of interactions with the pelagic false killer whales in the Hawai`i longline fishery for tuna.”

The take reduction team is scheduled to meet in Honolulu April 29 through May 1.

— Teresa Dawson

For Further Reading

Environment Hawai`i has published many articles on the interactions of the longline fleet with false killer whales. See, for example:

  • “Island False Killer Whale Population is Found to be at High Risk of Extinction,” November 2010;
  • “Lawsuits Yield Settlements to Boost Protection for False Killer Whales,” January 2013;
  • “Federal Fishery Council, Whale Expert Clash Over Fishing Impact on False Killer Whales,” August 2014.

All are available in the Archives section of our website:

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