Press Release – Council Science Advisors Recommend Peer Review for NOAA False Killer Whale Population Assessment, Approve Bottomfish Stock Assessment to Set Catch Limits (16 June 2023)

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HONOLULU (16 June 2023) This week the Council’s Scientific and Statistical Committee (SSC) discussed a NOAA assessment to quantify the population of pelagic false killer whales (FKWs) both inside and outside the U.S. exclusive economic zone (EEZ) around Hawai‘i to account for its overlap with the local commercial longline fishery. Previous assessments estimated the number of pelagic FKWs inside the EEZ and a broader Central Pacific area that is thought to include other distinct groups of whales. The new approach defined a “management area” based on available survey sightings, observed longline bycatch, and genetic and satellite telemetry tag data.

The resulting abundance estimate within the new area is 5,528 individuals. This total is used to calculate the potential biological removal (PBR), or the maximum number of individuals that can be removed from a population without causing it to decline below its sustainable level.

SSC members raised several concerns about the approach the NOAA Pacific Islands Fisheries Science Center (PIFSC) used to define the new management area boundary and the assumptions used to account for uncertainty in available data. The SSC noted a comprehensive explanation is needed on the data included and excluded from the new area. Alternative boundaries should be considered, including areas south of the proposed one where the species distribution model suggests high abundance of FKWs. The SSC recommended an independent peer review be conducted on the assessment, including validation of the underlying model.

“This is a complex issue and it’s important the FKW population estimate be as accurate as possible because it directly affects the Hawai‘i longline fishery,” said SSC member Milani Chaloupka, Ecological Modelling Services, Australia. “Available scientific information suggests that pelagic FKWs occur outside of the proposed management area boundary, and that these observations could be included in a more comprehensive assessment.”

FKWs are protected under the Marine Mammal Protection Act. When the number of fishery interactions that result in mortality and serious injuries (MSI) for the animals exceeds the PBR, the Act requires a Take Reduction Team to be formed to recommend a Take Reduction Plan. A team was formed in 2010 to address FKW interactions with the Hawai‘i deep-set longline fishery that targets bigeye tuna, and a plan was implemented in 2012.

In recent years, the estimated number of MSI in the deep-set fishery was below or one above the PBR for the portion of the pelagic FKWs inside the EEZ, which changes with new population approximations. Using the new approach that includes areas outside of the EEZ, PBR is estimated at 33 FKWs for the management area, and the MSI estimate is 47 from the deep-set fishery for 2017-2021 in the same area. Most FKWs accidentally caught in the fishery are released alive with the hook and some amount of trailing line left on the animal, which NOAA counts as serious injuries.

The SSC also determined a 2023 bottomfish stock assessment for American Samoa is the best scientific information available to use for developing annual catch limits. The new analysis resulted in the bottomfish stock status changing from overfished and overfishing occurring to not overfished or experiencing overfishing.

The PIFSC described updates from the 2019 to 2023 assessments to the SSC. The key differences were 1) using a new framework, which considers age and other characteristics of the population, and 2) splitting the 11 bottomfish species historically managed together in a species complex into individual species models. These changes allowed scientists to identify and fix errors in the data, such as when two species are very similar and may be misidentified.

PIFSC noted workshops organized in 2021 with fishermen in the territory, the Council and the American Samoa Department of Marine and Wildlife Resources (DMWR) provided valuable information to help interpret the available data.

“I appreciate the Science Center’s efforts to engage the fishermen and gather all the historical data,” said Domingo Ochavillo, DMWR Fisheries Biologist. “Working with the community was fruitful and made a big difference in resolving fishing data issues.”

The SSC also recommended rolling over the current acceptable biological catches for the CNMI bottomfish fishery for 2024-2025 (280,000 pounds) and the main Hawaiian Islands Kona crab fishery for 2024-2026 (30,802 pounds). The two limits are set to expire in 2023. The SSC evaluated the available data and analyses calculating the risk of overfishing and determined the existing limits were appropriate to extend.

Recommendations made by the SSC on these and other matters will be considered by the Council when it meets June 27-29, 2023, at the Governor H. Rex Lee Auditorium in Utulei, American Samoa. Instructions on connecting to the web conference, agendas and briefing documents are posted at

Scientific and Statistical Committee: James Lynch (chair); Jason Biggs (Guam Division of Aquatic & Wildlife Resources); Debra Cabrera (University of Guam); Frank Camacho (University of Guam); Milani Chaloupka (University of Queensland); Erik Franklin (University of Hawai‘i, School of Ocean and Earth Science and Technology); Shelton Harley (Fisheries New Zealand); Jason Helyer (Hawai‘i Division of Aquatic Resources); Ray Hilborn (University of Washington); Justin Hospital (NMFS PIFSC); Dave Itano (Fisheries Consultant); Donald Kobayashi (NMFS PIFSC); Steve Martell (Sea State Inc.); Domingo Ochavillo (American Samoa DMWR); Graham Pilling (Secretariat of the Pacific Community); Craig Severance (University of Hawai‘i at Hilo, retired); Francisco Villagomez (CNMI Division of Fish & Wildlife); Tia Brown (acting, ex-officio) (NMFS PIFSC).

Western Pacific Regional Fishery Management Council: Secretary of Commerce appointees from nominees selected by American Samoa, the CNMI, Guam and Hawai‘i governors: John Gourley, Micronesian Environmental Services (CNMI) (chair); Roger Dang, Fresh Island Fish Co. (Hawai‘i) (vice chair); Manny Dueñas, Guam Fishermen’s Cooperative Association (Guam) (vice chair); Will Sword, noncommercial fisherman/engineer (American Samoa) (vice chair); Judith Guthertz, University of Guam (Guam); Shaelene Kamaka‘ala, Hawaiian Islands Land Trust (Hawai‘i); Matt Ramsey, Conservation International (Hawai‘i); and McGrew Rice, charter boat captain (CNMI). Designated state officials: Dawn Chang, Hawai‘i Dept. of Land & Natural Resources; Sylvan Igisomar, CNMI Dept. of Lands & Natural Resources (vice chair); Chelsa Muña, Guam Dept. of Agriculture; and Archie Soliai, American Samoa Dept. of Marine & Wildlife Resources. Designated federal officials (voting): Sarah Malloy (acting), NMFS Pacific Islands Regional Office. Designated federal officials (nonvoting): Colin Brinkman, U.S. State Dept.; Brian Peck, U.S. Fish & Wildlife Service; and RADM Michael Day, U.S. Coast Guard 14th District.