The Institute of Cetacean Research
2025 IWC/Japan Joint Cetacean Sighting Survey Cruise in the North Pacific - Departure of the IWC-POWER research vessell
Jul 18, 2025
Designated Corporation for Scientific Whale Research
THE INSTITUTE OF CETACEAN RESEARCH
1. Background
This survey is conducted jointly by the International Whaling Commission (IWC) and Japan and is commonly referred to as IWC-POWER (International Whaling Commission/Pacific Ocean Whale and Ecosystem Research). IWC-POWER is the successor of IWC/SOWER (International Whaling Commission Southern Ocean Whale and Ecosystem Research), a successful whale research program acclaimed globally, which was conducted in the Antarctic Ocean from 1996/1997 to 2009/2010. Taking advantage of the know-how, experience and achievements of IWC/SOWER, IWC-POWER has been carried out every summer since 2010 based on the main research plan of the IWC Scientific Committee.
For the past fifteen years, the IWC-POWER research cruises have widely surveyed mainly the Northeast Pacific and have been covering a wide area of the North Pacific that had not been surveyed for several decades, finding large numbers of fin and sei whales in the Gulf of Alaska area north of 40 degrees north latitude and a large number of Bryde’s and sperm whales in waters south of 40 degrees N, and valuable data have been collected to contribute to objective stock assessment of these species. In addition, distribution information on rare species such as blue whales and right whales has also been collected.
This will be the 16th research cruise (the final year of the short-term research program). With the generous cooperation of the U.S. government, continuing from last year, this time we will conduct research mainly on gray whales in the Arctic Ocean (southern part of the Chukchi Sea: within the U.S. EEZ), as well as in the central waters of the Bering Sea (south of 69th parallel N latitude, north of the Aleutian Islands, east of 167° E longitude and west of 170° W longitude line, within the exclusive economic zone of the United States), from July 22 to October 9. The survey will be conducted by a total of four researchers, two each from U.S. and from Japan.
2. Outline of the 2025 Research Cruise
The IWC-POWER program is conducted collaboratively by the IWC and the Government of Japan. The IWC Scientific Committee has developed the research program and established the IWC-POWER Steering Group (Convenor: Koji Matsuoka, ICR), which has a role of designing the research plan and analyzing the results of the cruises. The Institute of Cetacean Research, under the commission of the Fisheries Agency of Japan, carries out the IWC-POWER cruises. The outline of this year’s survey plan is as follows:
2.1 Main objectives
(1) Collection of information for the in-depth stock assessment of humpback whales and gray whales.
(2) Collection of data on distribution and stock structure of the rare North Pacific right whale.
(3) Collection of data on abundance and stock structure of other whale resources with insufficient resource information.
(4) Collection of basic information, including oceanographic (sea water temperature, marine debris, etc.) necessary for the development of the medium- to long-term plan of this research program.
2.2 Research Cruise Period
From July 22 to October 9, 2025 (80 days)
2.3 Research Area
Waters part of the Chukchi Sea and of the Bering Sea (Figure 1).
The research vessel will call at the port of Dutch Harbor, Alaska to embark and disembark U.S. researchers and to load and unload survey materials.
Figure 1.2025 IWC-POWER survey area (green; within the U.S. Exclusive Economic Zone), and survey course (blue bold lines), and round-trip voyage (black-arrowed line).
2.4 International Researchers
The survey will be conducted by the following international researchers appointed by the IWC Scientific Committee.
Hiroto Murase (Cruise leader, Tokyo University of Marine Science and Technology, Japan)
Jessica Crance (Alaska Fisheries Science Center, NOAA/AFSC, USA)
Bernardo Alps (Southwest Fisheries Science Center, NOAA/SWFSC, USA)
Isamu Yoshimura (IWC-nominated international researcher, Japan)
2.5 Research Vessel
Yushin-Maru No.2,(747 tons, Captain Chikamasa Okoshi, 16 crewmen).
2.6 Operating body
The Institute of Cetacean Research (ICR, Japan)
Photographs from previous IWC-POWER cruises (Copyright IWC/ICR).
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| Blue whale breathing at sea surface (2022) | Head of a rare North Pacific rare whale (2023) | |
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| Fin whale surfacing（2021) | Caudal fin of a humpback whale photographed near the Aleutian Islands (2022) | |
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| International researcher deploying U.S.-made acoustic observation equipment (2023) | Observers and international researchers confirming whale species from the observation platform (2023) |
2025 IWC/Japan Joint Cetacean Sighting Survey Cruise in the North Pacific - IWC-POWER (PDF file)