72 REPOET OF COMMISSIONER OF FISH AND FISHERIES. 



The injtuence of icind and iceather. 



9G. On warm, calm, suuny days they may always be seen at the sur- 

 face, but cold or rainy weather, and prevailing northerly or easterly 

 winds, quickly cause them to disappear below the surface. In rough 

 weather they are not so often seen, though schools of them frequently 

 appear at the surface when the sea is too rough for the fishermen to set 

 tbeir nets. 



Mr. Atkins and Mr. Dudley agree that the best days for menhaden- 

 fishing is when the wind is northwesterly in the morning, dying out in 

 the middle of the day, and then springing up again in the afternoon 

 from the southwest, with a clear sky. At the change of the wind on 

 such a day the menhaden come to the surface in large numbers. 



A comparison of the influences of the weather upon the movements oi 

 the menhaden and its allied species, the herring, gives some curious 

 results. The herring is a cold-water species. With the advance of sum- 

 mer it seeks the north, returning to our waters with the approach of 

 cold weather. The menhaden prefers a temperature of 60^ or more, the 

 herring of 55^ and less. When the menhaden desert the Gulf of Maine 

 they are replaced by the herring. Cold weather drives the menhaden 

 to the warmer strata below, while it brings the herring to the surface. 



The observations of Herr von Freedon, of Hamburg, director of the 

 German See Warte,* are important in this connection. Herr von Free- 

 don made a thorough analysis of the log-books of the luggers engaged in 

 the German herring fishery, and made an elaborate report to the Fishery 

 Commission at Embden upon the influences which affect this fishery, 

 especially the influence of winds and the temperatures of the sea. He 

 has come to the conclusion that northwest winds are the best for large 

 catches, and northerly winds better than southerly, westerly better than 

 easterly ; also that moderately strong winds, sufBcient to ruffle the sur- 

 face of the sea, are better than calm weather, and light winds almost 

 as unfavorable as stiff breezes ; a ruffling of the sea being, in his oi)inion, 

 of considerable importance to success in fishing. For the temperatures 

 of the sea, he regards a temperature from 53° to 57° as most favorable, 

 the chances of success diminishing with higher or lower temperatures. 



The conditions most favorable, then, for the appearance of herring 

 afc the surface are least so for menhaden, it being borne in mind that 

 northwesterly and westerly winds on the east side of the Atlantic cor- 

 respond to northeasterly and easterly winds upon the west side. 



The movements of the herring as influenced by weather. 



97. In the " Scotsman " of August 25, 187G (quoted in " Nature "), is an 



interesting 'observation regarding the movements of the herring on the 



Scottish coast. The surface temperatures of the sea, as determined by the 



sea-thermometer furnished to the fishermen by the Scottish Meteorologi- 



* See Report of the Commissioner of tlie Fishery Board of Scotland, 1875. 



