304 



DISCOVERY REPORTS 



introductory section of this paper. It is not likely to be a direct effect of temperature (as seems 

 possible with M. bilinearis), for the range of temperature here is small, approaching British conditions 

 more closely than New England conditions. 



The broad fact that smaller fish are still closely congregated inshore, while large fish are beginning 

 to disperse offshore, seems sufficiently clear for us to state that the March results are consistent with 

 the view that the seasonal movement of M. hiibbsi is essentially similar to that of other species of hake 

 elsewhere. Ponderal indices also support this view: the small inshore population, with a probable 

 majority of late spawners and immatures, showed average K 20% higher than that of the larger 

 offshore population sampled at the same time. The latter must have completed spawning, for they 

 showed the lowest average K values (around 0-550) recorded at any season. 



In the Intermediate Region data covering more of the annual cycle are available, if we may con- 

 sider results obtained in different years as roughly comparable for our present purpose, but they are 

 scantier and less satisfactory than those from the northern region. We have already seen that the hake 

 diminish in numbers towards the south, so that this difficulty was only to be expected. 



In October and November no satisfactory series of observations was obtained here, but the size 

 and abundance of the hake at two stations, WS773 and 775, 206 and 82 miles off the land respectively, 

 were consistent with the view that a winter type of distribution still prevailed. Hake were nearly 

 twice as numerous at the offshore station where they were very much larger than those found farther 

 in. The proportion of males was greater inshore. Twenty-two juvenile hake of indeterminate sex, 

 less than 20 cm. long, were also captured during this period. This was at St. WS776, 60 miles from 

 the land. 



In December numerous observations were obtained during the third survey, but they were too 

 scattered, and the samples too small, to warrant individual treatment of the results. When the stations 

 are grouped according to their distance from the coast, the picture of frequency distribution obtained 

 IS m accordance with more conclusive results from farther north at the same season. It therefore 

 seemed legitimate to use similarly grouped data in studying the size distribution, etc., since although 

 either chain of evidence may appear bald and unconvincing by itself, they corroborate each other. 



Table 23. December data bearing on hake movements in the intermediate region, 5 to 22 December 1931 



* The mean would be misleading here (see text). 



These data are summarized in Table 23. It will be seen that the relative abundance was greatest 

 between 50 and 99 miles from the coast, and that the proportion of males was highest close in to the 

 land. The length data for males are unsatisfactory owing to wide dispersion in the small samples. In 

 distance grouping III a mean length for males would be meaningless, for the sample was composed 

 of some very small and a few large fish with intermediate lengths entirely unrepresented. The more 

 abundant length data for females tell a consistent story: the differences in mean lengths of the two 

 inshore groups from all the offshore groups are significant. The inshore fish were smaller, and the 

 offshore population apparently very homogeneous at this time. 



