THE HARBOR PORPOISE, PHOCOENA PHOCOENA, IN 



FISH HARBOUR, NEW BRUNSWICK, CANADA: 



OCCUPANCY, DISTRIBUTION, AND MOVEMENTS 



David E. Gaskin and Alan P. Watson^ 



ABSTRACT 



The distribution, movements, and relative population abundance of harbor porpoises were studied in the 

 Fish Harbour region of New Brunswick, Canada (lat. 44°59'30"-45°0r00"N, long. 66°54'00"-66°57'00"W), 

 from 1970 to 1978. In any given year numbers of this species were highest in the region between late July 

 and early September. This is also the period during which surface temperatures attain a maximum 

 (10°-12°C) and the largest herring, Clupea harengus, catches are usually made. During July-September the 

 porpoise population of the inner (western) part of the study area contained 63% mothers with calves. 

 Changes in relative population abundance were most strongly related with time of year (increasing from 

 early July), tidal amplitude (most present when amplitude is 6.5 m or less), and wind phase (most present 

 during onshore winds). Observation of recognizable individuals revealed consistent specific "territories" and 

 patrolling patterns. A marked decrease in relative abundance in the latter half of the 1970s was noted. This 

 decrease was coincident with a decline in mean midsummer surface temperature over 1974-78 of about 1°C. 

 Unfortunately it was not possible to determine from existing data if major changes in availability of prey 

 species also occurred in the inner Quoddy region during the same period. 



Literature concerning ecology of the harbor por- 

 poise, Phocoena phocoena, has been largely restricted 

 to reports of nonquantitative or casual observations 

 (Scheffer and Slipp 1948; M<)hl-Hansen 1954; Amun- 

 din and Amundin 1974), although more recently 

 Gaskin (1977), Prescott et al. (1981),^ Flaherty and 

 Stark (1982),3 Kraus et al. (1983)," and Taylor and 

 Dawson (1984) have presented information from 

 surveys and some population estimates for limited 

 areas of both east and west coasts of North America. 

 A population estimate for the Copper River area of 

 Alaska was provided by Matkin and Fay (1980). 

 Habitat indices, relating occurrence of animals in 

 coastal waters to various environmental factors have 

 been given by Smith and Gaskin (1983) and Watts 



'Department of Zoology. Universitv of Guelph, Guelph, Ontario 

 NIG 2W1, Canada. 



2Prescott, J. H., S. D. Kraus, P. Fiorelli, D. E. Gaskin, G. J. D. 

 Smith, and M. Brander. 1981. Harbor porpoise (Phocoemi 

 phocoena): Distribution, abundance, survey methodology and 

 preliminary notes on habitat use and threats. Final report to U.S. 

 Department of Commerce, NOAA, National Marine Fisheries Ser- 

 vice Contract 80-FA-d-00009, 61 p. 



^Flaherty, C, and S. Stark. 1982. Harbor porpoise (Phocoena 

 phocoena) assessment in "Washington Sound". Final report for 

 Subcontract 80-ABA-3584, NOAA, NMFS, National Marine 

 Laboratory, Seattle, WA, 84 p. 



^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 abun- 

 dance. A report to the National Marine Fisheries Service, Woods 

 Hole, Massachusetts, July 1983, 15 p. 



Manuscript accepted October 1984. 



FISHERY BULLETIN: VOL. 83. NO. 3. 1985. 



and Gaskin (in press), and some radiotelemetric 

 studies of distribution and movements by Gaskin et 

 al. (1975) and Read and Gaskin (1983, in press). 



In order to gain insight into the nature of local 

 distributions and movements of P. phocoena over an 

 extended period, we selected a semi-enclosed area of 

 limited size in southern New Brunswick, Canada. 

 Preliminary observations had already shown that the 

 species was common in the area, and locality (about 8 

 km- maximum) bounded approximately by lat. 

 44°59'30"-45°59'00"N, long. 66°54'00"-66°57'00"W 

 on the east coast of Deer Island (Fig. 1) was easily ac- 

 cessible for research and relatively sheltered. We 

 were also aided by the occurrence in the area of 

 several recognizable porpoises with surface 

 disfigurements, large blemishes, or distinctive 

 pigmentation patterns visible at some distance in 

 favorable light; several of these animals were pres- 

 ent in successive seasons. 



CHARACTERISTICS OF 

 THE STUDY AREA 



(Figure 1) 



Average depths range from about 8 m in Lords 

 Cove to about 22 m in Simpson's Passage (respective 

 maxima 20 m and 60 m) at mean low water. The 

 region is subject to anomalistic, semidiurnal tides of 



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