Federal Fishery Council, Whale Expert Clash Over Fishing Impacts on False Killer Whales

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At the Western Pacific Fishery Management Council’s meeting in June, Pacific Islands Fisheries Science Center (PIFSC) research ecologist Amanda Bradford presented new data on the ranges of Hawaiian false killer whales (FKW), which the council then seized on as proof that the Hawai`i longline fishery has a negligible impact on the insular stock, which is federally listed as endangered.
At the Western Pacific Fishery Management Council’s meeting in June, Pacific Islands Fisheries Science Center (PIFSC) research ecologist Amanda Bradford presented new data on the ranges of Hawaiian false killer whales (FKW), which the council then seized on as proof that the Hawai`i longline fishery has a negligible impact on the insular stock, which is federally listed as endangered.
Using satellite tracking data, as well as sighting data from the Cascadia Research Collective, the PIFSC has determined that individuals from the pelagic stock can occur in relatively shallow waters close to shore, that the Northwestern Hawaiian Islands stock ranges as far south as O`ahu, and that the insular stock consists of three clusters. Of greater importance to the council, the data also show that the insular FKW move further offshore on the leeward sides of the islands than they do on the windward sides. Bradford said they range as far off as 115 kilometers on the leeward sides and only 51 km off windward sides.

Despite the new data, she said, the Science Center will be keeping the stock boundary fixed for now. The current boundary extends 140 kilometers out around all islands. However, she continued, the PIFSC has formed a working group to assess the new data while a peer group will review boundary amendment recommendations. Revised boundaries will be included in the draft 2015 stock assessment review, she said.

Two weeks before the Wespac meeting, the National Marine Fisheries Service (NMFS) announced its preliminary finding that the Hawai`i deep-set (tuna-targeting) and shallow-set (swordfish-targeting) longline fisheries are likely to have a negligible impact on the insular FKW stock. With that finding, it went on to state its intent to issue a three-year incidental take permit to the fisheries. The permit, issued under the Marine Mammal Protection Act, would cover the fisheries’ incidental takes of insular FKW, as well as those of humpback and sperm whales.

In comments on the proposal, Wespac executive director Kitty Simonds wrote, “[T]he Council concludes that the fishery M&SI [mortality and serious injury] estimate for the … stock is overestimated and very likely to be less than 10 percent of the potential biological removal (PBR) based on the available scientific information.” PBR is the number of whales a fishery may kill or seriously injure within a specified time period without jeopardizing the stock. The annual limit for MHI false killer whales is currently set a 0.3 individuals.

Simonds argued that the assumption that the insular stock extends out 140 km is “overinflated,” given data Bradford presented showing that the whales did not venture further from windward shores than 51 km.

“All false killer whale interactions that NMFS has assigned to the insular stock have occurred on the windward sides of the MHI and far from areas where insular animals have been tracked with satellite tags,” Simonds wrote.

In his comments on the proposed permit, Cascadia Research Collective biologist Robin Baird could not have disagreed more with Simonds. Rather than being less than 10 percent of PBR, Baird estimated that the total Hawai`i fishery take of MHI false killer whales likely exceeds PBR.

He cites recent work by PIFSC statistician Marti McCracken that estimates that 0.45 MHI false killer whales are seriously injured or killed for every 1 million hooks set. Baird noted that the mean number of hooks set between 2008 and 2012 was 1,308,039, while the maximum number was 1,893,507.

Baird also pointed out that the prevalence of scars consistent with fishery interactions on MHI false killer whales is enough to suggest that “the individual rate of fishery interactions … may exceed that for pelagic false killer whales, where M&SI is known to exceed PBR.”

What’s more, because all sexed whales with fishery-related scars have been determined to be female, the estimates of M&SI may be negatively biased, he argued.

“[I]f a female involved in a fatal fisheries interaction has a dependent calf, it is probable the calf may not survive, thus effectively resulting in two mortalities,” he wrote.

Baird further argued that the MHI false killer whale population is not stable or increasing, and, in fact, sighting data suggest that the population is decreasing. He also stated that given the small PBR of 0.3 whales/year and the “relatively small overlap between the fishery and the populations’ range,” there aren’t enough federal observers on fishing vessels to produce a reliable estimate of M&SI by Hawai`i longliners.

Finally, he stated that too little consideration has been given to the role persistent organic pollutants may be having on FKW mortality rates. A study released this year on a 24-year-old female Hawaiian FKW that stranded in 2010 found that the whale was “highly contaminated” with PCBs and DDTs “well above the range of other free-ranging adult females.” Other studies have found dozens of Hawaiian false killer whales to have PCB levels that exceed acceptable levels.

“As such, this source of human-related mortality should be considered in the negligible impact determination,” Baird wrote.

The comment period closed on July 14. The NMFS had not issued the permit by press time.

Secret Data

Once again at the Wespac meeting, council members and SSC representative Charles Daxboeck alleged that data collected by Baird and used by NMFS to determine the PBR for Hawaiian FKW stocks have not been made available for independent review by the Scientific and Statistical Committee.

Daxboeck argued that data upon which public policy decisions are made should be readily accessible and that the council should be able to “get the data on which PBR is based.”

“Some of it is proprietary from Cascadia consulting. It has not been released,” he said.

To this, PIFSC research ecologist Erin Oleson pointed out that the PBR is based on the number of individuals in the NMFS photo catalogue and is not based on any private analysis Baird might have done. The PBR is based on photos of individual animals that are publicly available, and “anybody can look at each individual animal,” she said.

Daxboeck had no reply.

Despite Oleson’s clarification, the council voted to recommend that NMFS include a clause in all of its future contracts and permits to ensure that “all data used for public policy consideration are readily accessible.” The council also recommended that NMFS “obtain the scientific data upon which the MHI insular false killer whale stock assessment report is based, and cautions NMFS upon relying on such calculations until such data are obtained and independently reviewed.”

NMFS Pacific Islands Regional Office administrator Mike Tosatto abstained from both votes.

(For more background on this, see the Wespac articles in our May 2014 issue, available at www.environment-hawaii.org.)

– Teresa Dawson

 

Volume 25, Number 2 August 2014

 

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