Abstract. -Little is known of the 

 distribution, life cycle, and status of 

 the harbor porpoise Phocoena 

 phocoena in the northwestern Pacific 

 Ocean and adjacent seas. In the 

 present study we assess information 

 in the literature and re-examine 15 

 specimens in the National Science 

 Museum, Tokyo, in conjunction with 

 data from 45 new animals collected 

 from a variety of sources between 

 1983 and 1989. Maximum recorded 

 lengths of harbor porpoises from 

 Japanese waters are 158 cm for 

 males, and 185 cm for females, and 

 maximum age was 11 years. All fe- 

 males exceeded the average length 

 of North Sea females at given ages. 

 Size at birth is probably about 80 cm, 

 and parturition likely occurs in 

 May-June in northern Japanese wa- 

 ters, as in the North Atlantic. Known 

 and historical geographical limits 

 are given and compared with the 

 equivalent habitat conditions extant 

 in the western North Atlantic. The 

 most southerly winter record is from 

 Taiji, Wakayama, at latitude 34°15'N 

 and the most northerly confirmed 

 sighting from Shelikhova Bay in the 

 northeastern Sea of Okhotsk at 

 57°-58°N, in August 1989. The lat- 

 ter is unlikely to represent the 

 northern limit of the summer-fall 

 distribution. Seasonal migrations, 

 especially in and out of the Sea of 

 Okhotsk, must occur because of ex- 

 tensive ice coverage in winter, but 

 in Japanese waters there are con- 

 firmed records of porpoises as far 

 north as the northern tip of Hok- 

 kaido Island in January. 



Harbor Porpoise, Phocoena 

 phocoena (L), in the coastal waters 

 of northern Japan 



David E. Gaskin 



Department of Zoology, University of Guelph 

 Guelph, Ontario, CANADA N 1 G 2WI 



Satoru Yamamoto 



Kewalo Basin Marine Mammal Laboratory 

 University of Hawaii. Honolulu, Hawaii 96814 



Akito Kawamura 



Faculty of Bioresources, Mie University 

 1515 Kamihama. Tsu 5 I 4, JAPAN 



Manuscript accepted 2 April 1993 

 Fishery Bulletin 91:440^154 (19931 



Harbor porpoises, Phocoena phocoena, 

 are confined to the northern hemi- 

 sphere; a near-circumpolar distribu- 

 tion is found in temperate latitudes 

 (Tomilin, 1957; Gaskin, 1984). Al- 

 though most often sighted in coastal 

 waters, they also occur over adjacent 

 offshore banks, and sometimes over 

 deep water (Jones, 1984; Stenson 

 and Reddin, 1990). There are popu- 

 lations around relatively isolated 

 land masses, such as Iceland, and 

 harbor porpoises also occur in sub- 

 arctic and arctic waters, especially 

 in summer months (Van Bree et al., 

 1977). 



Interest in the harbor porpoise has 

 increased significantly in recent years 

 and Hohn and Peltier (1990) pub- 

 lished a useful bibliography of ar- 

 ticles on this species, although de- 

 tailed life history and distributional 

 data are still sparse in many regions. 

 Population surveys and life history 

 studies of the harbor porpoise have 

 been concentrated in the coastal wa- 

 ters of western Europe, the north- 

 western Atlantic, and northeastern 

 Pacific. Some pertinent references are 

 the following but the list is not ex- 

 haustive: Western Europe: Mohl- 

 Hansen ( 1954), Fraser ( 1974), Noldus 

 and de Klerk (1984), Kinze (1985, 

 1990a, 1990b), Anderson (1990), 



Bjorge and Kaarstad (1990), Bjorge 

 and Oien (1990), Evans (1990), and 

 Sequiera (1990); Black Sea: Zalkin 

 (1940), Tomilin (1957) and Celikkale 

 (1990)' Northwestern Atlantic: 

 Fisher and Harrison (1970), Gaskin 

 (1977, 1984), Gaskin and Blair 

 (1977), Prescott and Fiorelli (1980), 

 Kraus et al. (1983) 1 , Gaskin et al. 

 (1984), Gaskin and Watson (1985), 

 Yurick and Gaskin (1987), Polacheck 

 (1990), Polacheck and Wenzel 

 (1990), Read (1990, a and b), Fon- 

 taine et al. (1991), Read and Gaskin 

 (1990); Northeastern Pacific: 

 Flaherty and Stark 2 , Taylor and 

 Dawson (1984), Hannan et al. 3 , 

 Barlow (1988), Barlow et al. (1988), 



'Kraus, S. D., J. H. Prescott, and G. S. Stone. 

 1983. Harbor porpoise, Phocoena phocoena, in 

 the U.S. coastal waters of the Gulf of Maine: 

 A Survey to determine seasonal distribution 

 and abundance. Report to the Director, Na- 

 tional Marine Fisheries Service, Northeast Re- 

 gion, Woods, MA, 15 p. 



-Flaherty, C, and S. Stark. 1982. Harbor por- 

 poise iPhocoena phocoena) assessment in 

 "Washington Sound." NOAA, NMFS, National 

 Marine Mammal Laboratory, Seattle, WA, Fi- 

 nal Rep. for Subcontract 80-ABA-3584. 



'Hanan, D. A., S. L. Diamond and J. P. Scholl. 

 1986. An estimate of harbor porpoise mortality 

 in California set net fisheries April 1, 1984 

 through March 31, 1986. National Marine Fish- 

 eries Service, Southwest Region, Terminal 

 Island, CA, Admin. Rep. 5WR-86-16, 38 p. 



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