428 Scientific Proceedings, Royal Dublin Society. 



COMPAEISON OF THE HABITATS OF MATURE AND IMMATURE FISH 

 ON THE WEST COAST OF IRELAND. 



Whenever the material is sufficient I have prepared a Tahle showing, in vertical 

 columns, the size in inches of the fish, and in horizontal columns the depth in 

 fathoms at which they were taken. A dotted line divides the mature from the 

 immature, the limit heing that laid down in the last Table (p. 300), without considera- 

 tion of individual or sexual variation. Thus a number of really adult males are here 

 classed as immature, since they fail to reach the standard of size adopted, whilst 

 some few forms, which for some reason have failed to become adult, are nevertheless, 

 on account of their exceeding the given standard of size, classed as mature. 



On account of the number of different trawls used during the survey, I have given 

 the actual numbers in preference to percentages. Since it occasionally happened 

 that during a single haul we got soundings between which there was a difference of 

 more than five fathoms, I have endeavoured to divide the number of fish so caught as 

 equally as may be. So, also, in cases where the records do not show the exact numbers 

 at each size. Where the soundings or sizes of fish are not given in the records, I have, 

 of course, omitted the fish from consideration under this head. 



Dr. Fulton, in his excellent Paper on the " Distribution of Immature Fish," treats 

 the subject largely in reference to this occurrence within or without the territorial 

 limits. I was anxious to follow him in this, and, being in doubt as to the interpreta- 

 tion of the laws on the subject, I wrote to him, and in reply received a most courteous 

 explanation. In accordance with this guidance Mr. Beamish has kindly prepared for 

 me a chart showing the limits on the West coast of Ireland. 



From a glance at this it is at once evident that it is impossible to utilize the limit in 

 the same manner as the East coast of Scotland. The coast is so broken, and so many 

 islands, each with its own territorial area, intervene, that with the exception of the 

 outer and less important part of Donegal Bay, and the long stretch of ground west of 

 the (Galway) Aran Islands, there is not a single practical trawling ground which is 

 not enclosed by the three-mile Limit. The explanation is to be further sought in the 

 rapid shelving of the bottom, and the almost entire absence of banks such as are met 

 with in the North Sea {vide Mr. Green's Report, p. 51). Bearing in mind that the 

 ground never rises outside the limit, at least in a manner practicable for trawlers, a 

 list of the soundings (in fathoms) along the line may be instructive. Malin Head,. 

 29 to 20. The ground north of this may be good or bad ; at any rate it is not fished. 

 Round Tory, 37 to 30 ; Tory to Aranmore, 27 to 19 ; Tory to Dawros Head, 32 to 27, 

 except on Boylach Spit, a rocky prominence, with 14 fathoms ; Dawros Head to 

 Rathlin O'Birne, 46 to 32 ; Donegal Bay, 40, except where a narrow strip of extra- 

 territorial water intervenes between the limits of the narrow part of the bay and those 

 of Inishmurray, here the minimum soundings are 25 ; off Sligo and Killala Bays to 

 Downpatrick Head, 33 to 26; Downpatrick to Erris Head, 45 to 30; off Broadhaven, 

 38 ; Erris Head to Black Rock, 49 to 37 ; off Blacksod Bay, 49, except a triangular 

 patch of extra-territorial water which shoals to 39 ; Achill Head to Slyne Head, 68 to 

 49, except W. and N. W. of Clare Island, 29 to 18 ; Slyne Head to Inishmore, Aran 

 Islands, 60 to 40 ; off the Aran Islands, 40 to 30 ; Aran to Loop Head, 40 to 30 ; Loop 

 Head to Kerry Head, mouth of the Shannon, 49 to 19, the latter sounding being on a 

 rocky bank ; off Tralee (including Brandon) Bay, 36 to 19 ; Brandon Head to Sibyl 

 Head, 60 to 36 ; off the Blaskets, 60 to 40 ; off Dingle Bay, 40 to 29 ; off Ballin- 

 skelligs Bay, 59 to 29 ; off the Kenmare River, 56 to 41 ; Dursey Head to Mizzen 

 Head, off Bantry Bay, 48 to 33. It is not surprising, therefore, to find that, with the 



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