— 124 — 



also why they are discussed here in such a comparatively detailed manner. At a relatively 

 small distance from one another we find here waters of a true Atlantic nature with 

 temperatures never falling below ca. 6° and others which almost deserve the term arctic. 

 On the one side (on the eastern part of the south coast) we have an extremely well- 

 marked boundary between Atlantic water and Polar water, on the other side (on the north- 

 west coasts) there are the most even transitions between the warm and cold water, which 

 enables us in special degree to draw conclusions regarding the unequal sensitiveness of 

 the different species towards the temperature during the spawning time. Iceland which 

 lies on the boundary between the Atlantic and Polar Oceans and where such purely polar 

 species as the polar cod meet with the purely Atlantic has therefore within our region, in 

 spite of its relatively small extent, the great importance of being able to show us the 

 northern boundary (minimum temperatures) for the spawning of most of the Atlantic 

 gadoids with which we are here concerned. 



We have seen how all the species spawn in the constantly warm Atlantic water on 

 the south and south-west coasts, and also how the different species according to their dif- 

 ferent sensitiveness whilst spawning reach to different distances in the north on the west 

 coast. We have seen further how the temperature rises on the N. W. and N. coasts in 

 the course of the summer, as the Atlantic water ("Irminger Current") forces its way in an 

 anticydonic direction round the island (i. e. in the direction of the hands of a watch), by 

 which an "after-spawning" though extremely small is rendered possible on these coasts for 

 a few of the species which are less sensitive as regards the temperature (cod and further 

 lemon dab \Pleur. microcephalus]). 



It only now remains, before concluding this section on Iceland, to call attention to' 

 the extensive drift of the pelagic gadoid fry under the influence of the Irminger Current 

 northwards and westwards round the island in the summer. This has already been des- 

 cribed in detail for the cod (see p. 21), and the peculiar feature was there mentioned that 

 in spite of there being no cod fry produced on the cold east coast, yet the young bottom 

 stages of this species occurred there in enormous quantities perhaps greater than anywhere 

 else, and especially in much greater numbers than on the warm parts of Iceland where 

 they are spawned. We see in this on the one hand a distinct example of the statement 

 already made (see p. Ill) that the sensitiveness of a species is much greater during the 

 spawning than at any other time, and on the other hand an example on a large scale of 

 how the fry when in the pelagic stage may be carried a great distance by the currents. 



For the rest it is far from being all species which are carried to an equal extent by 

 the Irminger Current to the north and east coasts when in the pelagic stage. Those 

 species reach furthest which spawn earliest in the year and furthest to the north on the west 

 coast, for example, the cod (G. callarias), haddock (G. œglefinus) and the torsk (Brosmius 

 brosme), partly also though to a less extent and not with the same regularity the coalfish 

 {G. vir ens). On the other hand the fry of the Norway pout [G. Esmarki), ling {Molva 

 molva) and whiting (G. merlangus) take much less part in this movement. 



2. ThePseroes 

 The natural conditions in the Fseroese waters closely resemble those at the south 

 coast of Iceland and may be characterized as distinctly Atlantic with high winter 

 and low summer temperatures, as will be seen from the accompanying summary 



