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Fishery Bulletin 102(4) 



have been conducted on harbor porpoise iPhocoena pho- 

 coena; Barlow et al., 1988; Osmek et al., 1996; Calam- 

 bokidis et al. 3 ) and, to a limited degree, on humpback 

 whales ( Calambokidis et al., 1996, 2000) and gray 

 whales (Darling, 1984; Green et al., 1995; Shelden et 

 al., 2000; Calambokidis et al., 2002). Studies on pin- 

 nipeds and sea otters have also been conducted in this 

 region (Jeffries et al., 2003; Jameson et al., 1982, 1986; 

 Kvitek et al. 1992, 1998; Bowlby et al. 4 ). 



Information on humpback whales is of particular 

 interest because they were the primary species hunted 

 by whalers off Washington in the early 1900s. Since 

 then, little has been known about their movements and 

 distribution in this region. Photo-identification research 

 has helped define the movements and stock structure of 

 the humpback whales feeding off California (Calamboki- 

 dis et al., 1990. 1996, 2000). Calambokidis et al. (1996) 

 suggested that a demographic boundary exists between 

 humpback whales that feed off the coasts of California, 

 Oregon, and Washington and humpback whales feeding 

 farther north off British Columbia and Alaska. The 

 identity and degree of interchange of the whales that 

 feed in this boundary area have been unclear. 



Similarly for killer whales, photo-identification stud- 

 ies have revealed much about whale groups that fre- 

 quent the inland waters of Washington and British 

 Columbia (Bigg et al., 1990; Ford et al., 1994). Very 

 little is known about their occurrence off the coast, in 

 particular, about the "offshore" groups that are believed 

 to be a distinct race (Ford et al., 1994) that are seen 

 primarily offshore but occasionally also enter inland 

 waterways. 



We report here on the summer distribution of marine 

 mammals off the northern Washington coast based on 

 six ship line-transect surveys conducted between 1995 

 and 2002. These surveys were initiated to understand 

 marine mammal distribution and abundance in the 

 newly designated Olympic Coast National Marine Sanc- 

 tuary, as well as to collect information on seabirds, 

 oceanographic conditions, and juvenile fish. Each ship 

 survey was conducted between mid-June and late July. 

 Density estimates were made for the two most common 

 species: humpback whales and Dall's porpoise. In ad- 

 dition, photo-identification data gathered during these 

 ship surveys and from supplemental small boat surveys 



:i Calambokidis, J., J. C. Cubbage, J. R. Evenson, S. D. Osmek, 

 J. L. Laake, P. J. Gearin, B. J. Turnock, S. J. Jeffries, and R. 

 F. Brown. 1993. Abundance estimates of harbor porpoise 

 in Washington and Oregon waters. Report to the National 

 Marine Mammal Laboratory. National Marine Fisheries Ser- 

 vice, 55 p. Nat. Mar. Mamm. Lab., NMFS, 7600 Sand Point 

 Way NE F/AKC3, Seattle, WA 98115. 



4 Bowlby, C. E., B. L. Troutman, and S. J. Jeffries. 1988. Sea 

 otters in Washington: distribution, abundance, and activ- 

 ity patterns. Final report to National Coastal Resources 

 Research and Development Institute, Hatfield Marine Sci- 

 ence Center, 2030 S. Marine Dr., Newport, Oregon 97365, 

 131 p. Cascadia Research Collective, Wash. State Dept. of 

 Wildlife, Olympia, WA. 



within the same area between 1989 and 2002 provided 

 information on humpback and killer whale movements 

 and stock structure. 



Materials and methods 



Ship surveys 



Generally, ship surveys covered the area between the 20-m 

 isobath and the landward margin of the continental shelf 

 i200-m isobath) from the entrance to Strait of Juan de 

 Fuca to the mouth of the Copalis River to include the 

 boundaries of the Olympic Coast National Marine Sanc- 

 tuary (Fig. 1). Although the northern extent of these 

 waters is off southern British Columbia (Vancouver 

 Island), the entire overlapping region will be referred 

 to as northern Washington. 



Fourteen east-west tracklines were selected, follow- 

 ing permanent tracklines established by the NOAA 

 ship Miller Freeman in 1989. Tracklines were spaced 

 at 5-nmi intervals and were surveyed each year ex- 

 cept in 2002, when only ten lines were surveyed (four 

 southernmost lines were not included). Extra ship time 

 allowed for replicate surveys of the northern survey 

 legs in 1995, a short offshore extension of two lines 

 in 1996 and 2000 (up to 17 nmi in 1986), the addition 

 of three short east-west lines off southern Vancouver 

 Island around La Perouse Bank in 1997, and one ad- 

 ditional line that was surveyed south of the study area 

 in 2000 (Fig. 1). 



Ship surveys were conducted over a two-week period 

 in late-June and July 1995, 1996, 1997. 1998, and 2000 

 (Table 1). In 2002, a shorter, one-week survey was done 

 in mid-June. The marine mammal ship surveys were 

 conducted by a single primary observer from the vessel's 

 flying bridge (the sighting platform) with a viewing 

 height of 10 m above the water level. All surveys were 

 conducted from the NOAA ship Mc Arthur (55 m) except 

 during 2000, when the naval ship Agate Passage (33 m) 

 was used. From these platforms, the primary observer 

 scanned a 180-degree arc encompassing the area ahead 

 of the ship and abeam to either side. Observers used 

 reticle binoculars when possible and obtained measure- 

 ments of distance to a sighting derived from the angle 

 below the horizon (measured with graded reticles in the 

 binoculars) and the known platform height. For sight- 

 ings where the species could not be determined by the 

 observer, animals were identified to a general taxonomic 

 level (e.g., unidentified pinniped). 



Photo-identification surveys 



In addition, photo-identification data were examined that 

 had been gathered within the survey area. Research- 

 ers took photographs directly from the survey ship, or 

 from a Zodiac rigid-hulled inflatable that was launched 

 when animals were sighted. In 1996, the last two days 

 of vessel time on the McArthur were used to photograph 

 whales for identification. 



