WESTERN GRAY WHALE ADVISORY PANEL 17Th Meeting WGWAP-17/INF.8 11-13 November 2016 PUBLIC

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WESTERN GRAY WHALE ADVISORY PANEL WGWAP-17/INF.8 17th meeting 11-13 November 2016 PUBLIC WESTERN GRAY WHALE ADVISORY PANEL WGWAP-17/INF.8 17th meeting 11-13 November 2016 PUBLIC Weller et al: Gray whale migration in the western North Pacific SC/66b/BRG

Gray whale migration in the western North Pacific: further support for a Russia- Japan connection

1 2 3 4 5 DAVID W. WELLER , NANA TAKANAWA , HIROSHI OHIZUMI , NAOKO FUNAHASHI , OLGA A. SYCHENKO , 5 1 1 ALEXANDER M. BURDIN , AIMEE R. LANG AND ROBERT L. BROWNELL, JR. Contact e-mail: [email protected] 1 NOAA Fisheries, Southwest Fisheries Science Center, La Jolla, California USA 2 242 Toshimamura, Tokyo, JAPAN 3 Tokai Universiy, Department of Marine Biology, Shimizu, JAPAN 4 Tokyo, JAPAN 5 Kamchatka Branch of Pacific Institute of Geography, Russian Academy of Sciences, Kamchatka, RUSSIA

INTRODUCTION The current migratory routes and wintering areas of gray whales in the western North Pacific are enigmatic. Historical evidence indicates that coastal waters off Japan were an important part of the migratory route but modern day observations of gray whales off Japan are uncommon. Fewer than 30 sightings or strandings of gray whales in Japanese waters have been documented between 1990 and 2016 (Nambu et al. 2010; Nambu et al. 2014; Aoyagi et al. 2015, Kato et al. 2015). This paucity of records may reflect a true rare occurrence of this species off Japan or possibly be related to limited research effort or reporting of opportunistic sightings.

RESULTS Here we report on the migratory movements of a photo-identified gray whale (no. 233) moving back and forth between Sakhalin Island, Russia and the Pacific coast of Honshu, Japan during 2014 to 2016. These observations include: (1) Russia (August 2014) - whale no. 233 was first identified as a calf off Sakhalin Island (Fig. 1) and was observed three times together with its mother and one time alone during August 2014. The mother of this calf is a known 12-year old female. She was first sighted off Sakhalin Island as a calf in 2004, has been sighted nearly annually since then. She was sighted with her first known calf (no. 233) off Sakhalin in 2014. (2) Japan (March 2015) - whale no. 233 was photographed off Kozushima1. Kozushima is one of the seven islands in the Izu Archipelago and is approximately 180 km south of Tokyo (Fig. 1). (3) Japan (March 2015) - whale no. 233 was photographed off Niijima1 (another Izu Island; Fig. 1). (4) Japan (April and May 2015) - whale no. 233 was photographed in Suruga Bay2. Suruga Bay is located on the Pacific coast of Honshu (Fig. 1). (5) Russia (August 2015) - whale no. 233 was photographed off Sakhalin Island3 (Fig. 1). (6) Japan (January 2016) - whale no. 233 was photographed in Sagami Bay4. Sagami Bay is located on the Pacific coast of Honshu (Fig. 1). (7) Japan (February 2016) - whale no. 233 was photographed off Miyake-Jima5 (another Izu Island; Fig. 1).

1 Photos - N. Takanawa 2 Photos - M.Tatsunami, Chunichi Newspaper 3 Photos – Russia Gray Whale Project, A.M. Burdin. 4 Photos - https://www.facebook.com/nishikawana/posts/1145969495414172 5 Photos - https://www.facebook.com/eiji.yamazaki.7/videos/929475013827287/?fref=nf

1 WESTERN GRAY WHALE ADVISORY PANEL WGWAP-17/INF.8 17th meeting 11-13 November 2016 PUBLIC Weller et al: Gray whale migration in the western North Pacific SC/66b/BRG

The occurrence of gray whales off the Izu Islands has been previously reported (Darling 1994). In April 1993, three gray whales were photographed by K. Nakamura while migrating north in coastal waters off Izu-Oshima, the northernmost of the islands in the Izu Archipelago. All of the seven Izu Islands are in close proximity to each other. In combination, past and current information indicates that gray whales have been observed sporadically at a majority of the Izu Islands. Similarly, a number of relatively recent records of gray whales in coastal waters off Japan also exist, including some from the the Pacific and Sea of Japan coasts of Honshu (Kato et al. 2015; Aoyagi et al. 2015). One of these records includes a female yearling entrapped in a set net in January 2007 that was matched to earlier photographs of it as a calf (with its mother) while on the Sakhalin feeding ground in July and August 2006 (Weller et al. 2008). This match from 2006 (Sakhalin) and 2007 (Pacific coast of Honshu) along with the new matches reported here between 2014 and 2016 provide additional verification of a migratory link between the summer feeding ground off Sakhalin Island and a wintering location somewhere along the coast of Asia, likely to be south of Honshu. Sighting records for whale no. 233 off Japan occurred during March-May and January-February. The March-May period corresponds with the time when gray whales in the eastern North Pacfic (ENP) are migrating north from Mexico to the Bering Sea. The January-February period corresponds with the ENP southbound migration when whales are moving from the Bering Sea to Mexico. The August sightings of whale no. 233 off the Sakhalin Island feeding area correspond with when ENP whales are on their summer feeding grounds in the Arctic. With this in mind, we hypothesize that the March-May and January-February records from Japan, inclusive of the earlier record in 2007 (Weller et al. 2008), represent sightings during the north-south migration within the western North Pacific. The movements of whale no. 233 reported herein appear to link a wintering area somewhere off Asia to the summer feeding area off the northeastern coast of Sakhalin Island.

4 3 2

Figure 1. Point 1 = Sakhalin Island, Russia. Point 2 = Izu Islands, Japan: Kozushima, Niijima and Miyake-Jima. Point 3 = Sagami Bay, Japan. Point 4 = Surgua Bay, Japan

2 WESTERN GRAY WHALE ADVISORY PANEL WGWAP-17/INF.8 17th meeting 11-13 November 2016 PUBLIC Weller et al: Gray whale migration in the western North Pacific SC/66b/BRG

LITERATURE CITED Aoyagi, A., Okuda, J., Imamura, M., Ebira, A., Ohara, J., Honma, Y., Nambu, H. and Yamada, T.K. 2015. Observations of a gray whale, Eschrichtius robustus, off the Niigata coast, Sea of Japan in the spring of 2015. Japan Cetology (25):7-16. [In Japanese] Darling, J. 1994. Seeing ghosts -gray whales in the Orient. Ocean Realm Magazine, January:18-19. Kato, H., Kishiro, T., Bando, T., Ohizumi, H., Nakamura, G., Okazoe, N., Yoshida, H., Mogoe, T. and Miyashita, T. 2015. Status report of conservation and researches on the western North Pacific gray whales in Japan, May 2014-April 2015. Paper SC/66a/BRG18 presented to the International Whaling Commission Scientific Committee. [Available from http://www.iwcoffice.org/] Nambu H., Ishikawa H. and Yamada, T.K. 2010. Records of the western gray whale Eschrichtius robustus: its distribution and migration. Japan Cetology (20):21-29. [In Japanese] Nambu, H., Minowa, K., Tokutake, K. and Yamada, T.K. 2104. New observations on gray whales, Eschrichtius robustus, from central Japan, Sea of Japan. Japan Cetology (24):11-14. Weller, D.W., Bradford, A.L., Kato, H., Bando, T., Ohtani, S., Burdin, A.M. and Brownell, R.L., Jr. 2008. Photographic match of a western gray whale between Sakhalin Island, Russia, and Honshu, Japan: First link between feeding ground and migratory corridor. Journal of Cetacean Research and Management, 10(1):89-91.