3o6 



DISCOVERY REPORTS 



Finally, during the second survey, a series of observations in June (midwinter) yielded two rich 

 hauls at the greatest distance offshore, while farther in there were few hake, and only a singleton 

 within loo miles of the land. These results also showed that, as at all times except midsummer, the 

 mean lengths of the more adequate samples increased with their distance from the coast, and at the 

 same time the proportion of males diminished. 



Table 26. June data bearing on hake movements in the intermediate region, i to 8 June 1928 



* Too few for means to have any significance. 



CONCLUSIONS ON MIGRATION 

 The relative abundance of the hake caught in relation to distance from the coast is the best means of 

 studying the probable seasonal movements of M. hubbsi, from our unavoidably limited data. For 

 comparative purposes the catches per hour for each series of observations may be summed, and the 

 catch at each distance category expressed as a percentage of the figure so obtained. A diagrammatic 

 summary of the seasonal observations, obtained in this way, is shown in Fig. 25. 



We have seen also that comparisons of mean lengths and sex ratios corroborate the general picture 

 so obtained, wherever the data are adequate. 



M. hubbsi seems to migrate towards the coast in summer, and offshore in winter, in much the same 

 way as do better known species of hake elsewhere. It would seem that as in M. merlucciiis, the larger 

 females move inshore first, passing their smaller sisters who may, however, begin to shoal somewhat 

 earlier. There is a strong suggestion that the smaller fish are rarely abundant at the greater distances 

 from the coast ; probably they do not migrate so far or so fast as the bigger ones. This may be a function 

 of size, and not only due to the greater proportion of immature fish among the smaller individuals, for 

 the proportion of males always diminished as one proceeded seawards, and in this species, where' the 

 disparity in size between the sexes is much more marked than in M. merhiccius, it is certain that many 

 of the males of even the smallest length class are mature. Probably the movements of males show 

 some marked differences from those of the females: the proportion of males was noticeably high in 

 March, at the time of greatest shoreward concentration of the smaller females, still fairly high when 

 seaward movement had begun in April, and low at all other seasons. This suggests that, except at 

 the height of the breeding season and for a short period afterwards, the males are more widely dis- 

 persed, and less inclined to shoal, than are the females. 



Although M. hubbsi seems to move shorewards in a double wave rather like M. merhiccius, this 

 movement begms later m the year, and in this respect perhaps resembles more closely the movement 

 of M. bibneans. It is thought that this is probably connected with the general lateness of the biological 

 seasons in this part of the southern hemisphere, which has been described in the introduction to this 

 report. In M. bihnearis the later timing of the cycle may well be a direct effect of temperature, for off 

 New England the annual range is great. It is unlikely to be so off Patagonia, where the annual cycle 



