170 BULLETIN OF THE UNITED STATES FISH COMMISSION. 



rorable weather which prevailed in the southern part of Iceland during 

 1884 would have seriouslv interfered with mv observations. luvesti- 

 gatious of this character should be continued for some length of time 

 before definite results can be reached, and repeated visits should be 

 paid to most of these localities, and their natural conditions should be 

 ■examined more thoroughly. 1 felt this particularly on returniug home 

 and looking over my notes and collections. There is no doubt that 

 another visit to Iceland, made about a month earlier than my visit and 

 extended to .some rivers and lakes which 1 failed to see. would serve to 

 furnish a more reliable basis for observations. It should not be forgotten 

 that this is the first attemjit which has ever been made to describe the 

 Iceland fresh-water fisheries. Neither Eggert IJlafson, Bjarne Poulsen, 

 nor Faber and others have given reliable and full descriptions of these 

 fisheries, and oF the natural conditions under which they are carried on. 

 I had to begin from the very beginning, and had no previous observa- 

 tions that could in any way be relied on, wherefore my work must be 

 considered as merely a first attempt. 



It IS quite natural that, in view of the large number and extent of 

 the rivers and lakes of Iceland, and of the vast quantity of water con- 

 tained in them, at least during i^artof the year, we should inquire what 

 economical value they possess as fishing waters. It should at the same 

 time be remembered that something more than water is needed for the 

 life and well-being of fish, and that the weather and the character of 

 the land surrounding the water are of the greatest importance. The 

 weather prevailing in Iceland at certain seasons of the year proves a 

 great hindrance to the life of fish, and the character of the country has 

 a great influence on the number of fish in the fresh waters of Iceland. 



The cold weather not only hinders the development of plants and 

 the lower animals in the watercourses and lakes, but it also produces 

 physical conditions which hinder and destroy the life of fish. It is an 

 old saying in Iceland that those rivers which come from the mountains, 

 and which have a whitish color from the inorganic matter which they 

 carry, nevertheless contain salmon, as these fish do not seem to sbun 

 muddy water, especially if through it they can reach clear water- 

 courses which they like. But most of the mountain streams are so cold 

 the greater part of the year, and have so much ice, frequently just be- 

 fore summer sets in, that the spawning salmon and the young fry are 

 exposed to considerable danger. The ice dams up the water and dis- 

 turbs the botton), carrying along stones and gravel and forming new 

 channels for the water; and it may well be said that where the ice is 

 found in large masses the fish decrease in number. If the cold weather 

 continues for any length of time much bottom-ice forms in these waters, 

 which, when milder weather sets in, rises from the bottom, carrying 

 away sand and gravel and the fish eggs which may be concealed in it. 

 This influence of the ice on the life of fish has been observed in several 

 waters, and in Iceland this is a matter of considerable importance. 



