526 REPORT OF COMMISSIONER OF FISH AND FISHERIES. [2] 



animals. Warmth, which furthers tjie rapid development of plants and 

 small animals which serve as food for fish ; currents, which carry plants 

 and embryonic animals in constantly varying quantity to the fishing- 

 places, are some of the causes which necessarily must exercise an influ- 

 ence on the migrations of fish to such places. 



No one will expect that fishermen should go to sea with thermometers 

 and areometers ; but the fishermen will be benefited if the above-men- 

 tioned conditions of the sea-water are regularly examined and com- 

 pared with the results of the fisheries. The fishermen, without making 

 any scientific investigations, may aid greatly in extending our knowledge 

 of these matters, and may benefit their trade by paying close attention 

 to such easily recognizable circumstances as high or low temperature, 

 currents, and to various phenomena connected with the spawning of fish, 

 the greater or less quantity of fish at different places and seasons, &c, 

 and by making their observations public. 



These considerations induced the Ministry of Agriculture, &c, in the 

 year 1870, to appoint a commission at Kiel for the purpose of making 

 scientific examinations of the German waters, which might aid in gain- 

 ing a better knowledge of those conditions on which the success of the 

 salt-water fisheries — their improvement and extension — depends. For 

 this purpose a number of stations have been established where the con- 

 dition of the sea- water is regularly examined, whilst, at the same time, 

 similar observations are made by several vessels following a certain 

 regular course. At some of these stations observations are also made 

 with a view of ascertaining (in exact figures) the result of the fisheries. 

 A beginning has also been made in making observations regarding the 

 spawning places and seasons, the development of fish, &c. 



Our knowledge is still quite limited, and so far, at least, the practical 

 result of these investigations has not been very great ; but we must 

 take into consideration the fact that but a short time has elapsed since 

 these investigations were commenced. 



No year resembles another in its atmospheric conditions, and meteor- 

 ology, although studied for several centuries, has not yet been able to 

 fix with absolute certainty the rules from which for some time in advance 

 the condition of the weather could be calculated. The sea has likewise 

 its atmospheric changes, dependent on many different circumstances, 

 and many years will pass before we shall ascertain the causes of these 

 changes observable in different years. The conditions of life and the 

 habits of salt-water fish have scarcely begun to be studied. Fishermen 

 themselves know but little with absolute certainty regarding the spawn- 

 ing places and seasons of the more important salt-water fish of their 

 own familiar waters. It may as well be acknowledged that so far we 

 only know a few facts regarding the spawning places and seasons and 

 the development of one species of fish — a very important one, to be 

 sure — the herring ; but even these observations have reference to only a 

 few localities. But what we know is highly important, because it has 



