232 



O. Nordgaard. 



the Varanger Fiord and suddenly he caught sight of a little box 

 floating in the water. On closer examination, he found, to his 

 great surprise, that his own name and address was written on it. 



It had been sent by the „Nordstjernen" from Kristiania, and 

 after the wreck of the vessel „the clever little box" had found its 

 own way to its destination, which is a fanciful expression of the fact 

 that winds and waves had carried it to the inner part of the 

 Varanger Fiord. 



Outside the prominent rocks of Finmarken, the tidal currents 

 are very strong, the direction being easterly when the tide rises, 

 and westerly during its fall. 



T have had personal experience too of the strength of tidal 

 currents. In the summer of 1894, in the course of a zoological 

 expedition in Finmarken, I was out in a little boat on August 

 14th and had three men with me, I intended to pass Nordkyn 

 going west. We had been sailing a little while, but the wind 

 ceased and we were obliged to try to row; this was exactly oppo- 

 site Nordkyn. The stream was, however, against us, and it proved 

 to be utterly impossible for us to make any headway. Fortunately 

 the water was so shallow just here that we were able to anchor 

 until the current slackened. 



That the tidal currents have a considerable carrying capacity. 

 I have also noticed in Nygaardsstremmen at Bergen, very near 

 the Biological station. Not only large mussels but mediumsized 

 specimens of a star-fish (Asterias minus) now and then sail along 

 with this current. So it is not strange that bottom forms, as for 

 instance Foraminifera, are often found in plankton. Currents and 

 winds play also an important part in the fact that plankton is 

 heaped up in quantities at certain special places. A closer study 

 of this subject will undoubtedly throw light on tilings connected 

 with the catch of plankton-eaters, such as herrings, sprats etc. 



Lately, it has become clear to me that the downfall plays 

 an important part in the hydrography and biology of the fiords. 

 My thoughts were first turned in this direction, when I noticed 

 that an increase of salinity occurred in the fiords of northern 

 Norway, from January and throughout the spring. In the fiords in 

 the neighbourhood of Bergen too, I have seen that the surface 

 salinity is greatest in the winter, as the downfall then is least and 

 there is a portion which does not exert its influence for the time. 

 One would then expect that the great difference in downfall in the 

 west and north of Norway would be remarkably felt, and this is 

 clearly shown to be the case. 



A closer study of the downfall also gives an explanation of 

 the fact that the deeper layers in the Porsanger Fiord have such 

 a low temperature. According to Gran, 1 ) Dr. Hjort found on 

 the 24th of August 1900 the following conditions in Osterbotten, 

 which is connected by a shallow channel with the rest of the 

 Porsanger Fiord: — 



According to Mohn, 2 ) the annual average temperature at 

 Kistrand, which is in the inner part of the same fiord, is o°.8 C. 



The annual average downfall for the years 1896 — 1902 at Older- 

 oen at the end of the Porsanger Fiord is reckoned to be 374 mm. 1 ). 

 In the years 1899 and 1900, the downfall for the different months 

 was found to be as follows: 2 ) — 



1 d e r o e n. 

 Downfall. 



January 



February 



March 



April 



May 



June 



July 



August 



September 



October 



November 



1 )eeember 



Year 



18 

 22 

 25 

 12 

 11 

 2 



62 

 30 

 11 

 20 

 32 

 10 



1900 



255 



16 



15 



28 

 o 



5 

 24 

 94 

 69 

 23 

 17 

 67 

 49 



409 



1 ) Das Plankton ties norwegisclien Nordmeeres. Rep. Norw. Fish, and 

 .Marine Investigations, vol. II, nr. 5, 1902, p. 1 12. 



2 ) Klimatabeller for Norge, I, p. is. 



As a consequence of the slight downfall in the winter, the 

 salinity of the surface layers constantly increases, and in this way 

 there is a tendency to great regularity both in the temperature and 

 salinity of the layers. 3 ) But under these circumstances, the cooling 

 of the surface by means of the vertical current will be felt far 

 down. (Cf. Hydrography, p. 17) and the cold of the arctic winter 

 will, in this way. penetrate down into the deeper layers. When 

 the state of things is like that in Osterbotten. where a shallow 

 channel effects the connection with the fiord, the warm under- 

 currents cannot penetrate. Then too, the summer downfall is much 

 more effective than that of the winter, so the mixing on the sur- 

 face in the summer will serve to prevent the summer heat from 

 penetrating downwards. Taken together, these things will. I think, 

 explain Dr. Hjort's surprising statement of -5- 1.02 at a depth of 

 90 mtrs. in Osterbotten, and will also give a clue to the fact that 

 most of the arctic animals are found in the inner parts of the fiords; 

 It should also be remembered that the longer a fiord is, the more 

 will the continental influence be felt. 



In western Norway, a different state of things is found in 

 such shut-in basins as Osterbotten. I have studied conditions in 

 the Lyse and the Mo Fiords, both of which belong to districts 

 which form centres for the maximum downfall in Norway. At the 

 station Nedrebo. in the Lyse river district, the average fall from 

 1896 — 1902 was 2 169 mm.; and at the station Farstveit. in the 

 Mo river district, it was 2 733 during the same period. 



I beg to refer to what I have recently written about these 

 fiords. 4 ) Now I will only mention that while the bottom water in 

 Osterbotten contains degrees of cold from the winter, the bottom 



J ) Nedberiagttagelser i Norge. aarg. VIII, 1902. p. 125. 



2 ) Cf. Nedbariagttagelser, aarg. V, VI. 



3 ) Cf. Hydrogr. Tables nrs. 833—846. 



4 ) Studier over naturforholdene i vestlandske fjorde. I. Hydrografi. 

 Mns. Aarb., nr. 8, 1903. 



m 



Berg. 



