REPORT OF COMMISSIONER OF FISH AND FISHERIES. Vll 



Having been so fortunate as to interest Professor Peirce, of the Coast - 

 Survey, in the general inquiry intrusted to me by Congress, I received, 

 under his instructions, from Captain Patterson the proffer of the aid of 

 that branch of the service in pursuing such investigations as related in 

 any way to its own objects ; and as the physical and natural history of 

 the various banks oft' the New England coast constituted a common 

 bond of interest, it was determined by the Superintendent to fit out the 

 steamer Bache to make surveys on George's Banks, one of our best 

 fishing-grounds. I was authorized to put on board two experts in the 

 line of marine zoology, for the purpose of prosecuting the necessary 

 inquiries; and having selected Mr. S. I. Smith and Mr. Harger, these 

 gentlemen presented themselves at Provincetown, as the place of ren- 

 dezvous, at the appointed time. While certain needed repairs of the vessel 

 were being completed, these gentlemen in the interval visited Eastport 

 and entered iiito the general inquiries prosecuted in the Bay of Fundy 

 They, however, returned to Provincetown when the Bache was ready to 

 take them on board ; and although beginning their work so late in the 

 season, as to be interfered with by storms and unfavorable weather, they 

 succeeded in securing many valuable results, a report of which will be 

 presented hereafter. 



boats out in each district, were extracted from the reports, and an average of these 

 six years calculated at several of the stations. These were finally compared day by 

 day with two series of sea-temperatures ; one taken off Harris, and the other near 

 Edinburgh. 



The temperature of the sea was found to rise very rapidly about the middle of July ; 

 and to keep oscillating slightly about a uniform temperature of 56~' until the 13th of Au- 

 gust, when it rapidly rose to the annual maximum, namely, 57°.2, and ranged relatively 

 high until the first of September. This period of highest annual temperature, namely, 

 from the middle of July to the first of September, was found to be coincident with 

 the fishing-season in the northern districts of Scotland ; and the period when the tem- 

 perature rises to the absolute maximum is further coincident with the date of the 

 largest catches during the fishing-season. The committee, however, consider it pre- 

 mature to lay great stress on the striking coexistence of these facts, since it is impos- 

 sible, without further statistics, to say whether these relations are of a permanent 

 character. The fishing-season did not begin until the sea-temperature had risen to 

 about 55*0 in July, nor did it continue after it had fallen below 55^° in September. 



An important omission in these tables is, that they do not show whether they indi- 

 cate the surface or bottom temperature of the sea; the difference in this respect being 

 very appreciable. Another omission is, as to the relation between the spawning-sea- 

 son of the herring and their shoreward movement. Along the coast of the United States, 

 the great spawning-ground of "the sea- herring is off the southern end of Grand Manau, 

 where the surface and bottom temperatures sometimes differ at the spawning-season by 

 as many as five or six degrees. 



An important relation was also observed by the committee between the exceptional 

 atmospheric temperatures and the migrations of the herring, the fishing-season begin- 

 ning much later in the year, when the summer-temperatures are low, than when 

 they are high. As regards the relation between barometric observations and the 

 fisheries, it appears that during the periods when good or heavy catches were taken, in 

 a great majority of cases the barometer was high and steady, the winds light or mod- 

 erate, and electrical phenomena wanting; when the captures were light, the observa- 



