FISHERY BULLETIN: VOL. 83, NO. 3 



Figure 3. - Locations in Fish Harbour at which fish were detected visually or by sonar in 1973-78; opportunistic records only. Stipple: species 

 not identified; vertical bars: Atlantic mackerel: diagonal bars: Atlantic herring; circles: one or more porpoises simultaneously present with 

 record; arrows: direction of fish movement. The size of hatched areas indicates approximate size of the school. 



1983), some could have been of harbor pollack, which 

 are also taken by this species. 



Changes in Distribution Within 

 the Fish Harbour Region 



No differences in distribution of the 669 recorded 

 sighting positions for 1973-75 could be detected 

 when they were plotted either by four or eight time 

 periods from 0600-2200, but considerable differences 

 were evident when they were plotted against eight 

 subphases (slack low, slow flood #1, fast flood, slow 

 flood #2, slack high, slow ebb #1, fast ebb, and slow 

 ebb #2) of the tidal cycle. This analysis ignores for 

 the moment the fact that many animals move in a 

 rather regular manner through the study area, since 

 useful information can be obtained simply from 

 noting where they are at any given time of tide. The 

 results (Fig. 4) showed that up to 80% of porpoises 

 were congregated over the shallow shelf margins, 

 slopes, and scarp areas between the onset of flood 

 tide and high water. Conversely, about the same pro- 

 portion became concentrated over the basin and 

 channel areas between onset of the ebb, and slack 

 low water. 



The Nature of Movements Within 

 the Fish Harbour Region 



It became evident that when the recognizable 

 animals returned each year they reestablished 

 "specific ranges" (for lack of a better term) in virtu- 

 ally the same locations in Fish Harbour each summer 

 (Figs. 5-8). There is some evidence that these 

 "ranges" shifted progressively further east of Deer 

 Island between 1973 and 1975, especially in the case 

 of the scarred female mentioned earlier. Each of 

 these areas in Fish Harbour, of which we were able 

 to measure nine approximately, appeared to be about 

 1.0-1.5 km^ in extent. Even the most distinctive 

 animals would disappear from the study area for ex- 

 tended periods and then reappear again, just as 

 Gaskin et al. (1975) noted for a female carrying a 

 radiotelemetric package. The scarred female was 

 once observed with a calf off the eastern coast of 

 Simpson's Island, and on another occasion between 

 Minke Ledges and Tinker Island, which lie between 

 1 and 3 km south of the main study area. This speci- 

 men was present in the Fish Harbour region for 

 about half the days of excellent visibility in 1973-75, 

 was well known to all observers, and yet was only 



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