HISTORY OF THE AMERICAN MENHADEN. 55' 



1874, December iu Charleston averaged 4S°.8 ; iu 1875, January aver- 

 aged 50O.2. 



The movements of the menhaden in this region have not been 

 observed, but since in the north it is not more hardy than the shad, and 

 since the shad do not venture into the Georgia and Carolina rivers in 

 December, it is safe to predict that the habits of the menhaden are 

 similar. 



Jacksbnville, Fla., is the only point on the east coast from which there 

 are observations showing a temperature uuformily above 51°, and here 

 the menhaden remain throughout the winter. 



Maxirmim limits of temperature. — On the coast of Eastern Maine we are 

 told that the menhaden schools keep passing to the eastward until about 

 the middle of July, when their impetus is apparently checked and their 

 movements for thirty or forty days seem to be local only. During this 

 period the temperature at Portland ranges Irom 00° to 70°, this being 

 the height of mid-summer. The monthly means for July and August, 

 1S7G, were GG°.7 and Co^.O. The same months at New London are 

 placed at 73° and 73^.3 ; at Norfolk, 84o.l and 78o.3. Wilmington, 

 Charleston, and Savannah do not range much above Norfolk ; June, 

 July, and August at Jacksonville average above 85°, and we have no 

 satisfactory evidence that the menhaden are seen there in mid-summer. 

 At Key West the lowest monthly mean is December, at GGo.4, in an 

 unusually cold winter. 



Preferred range of temperature. — These facts appear to indicate that 

 under ordinary circumstances the menhaden prefers a temperature of 

 GO^ to 70° Fahrenheit. AYhen the rising temperature of spring has passed 

 the limit of 50° to 51° the fish are certain to appear, and when the fall- 

 ing temperature of autumn reaches that point their departure is equally 

 sure, though a few individuals may linger in waters not congenial to 

 them. The opposite limit seems to be marked by the line of 80° or per- 

 haps 75°. An easterly or northerly wind, lowering temporarily the sur- 

 face temperature, causes the schools to sink below the surface, as is shown 

 iu paragraph 95- The chill of night also drives them down. 



These conclusions are not to be regarded as final. The movements 

 of the fish about Cape Ilatteras are very puzzling and need to be inter- 

 preted by a series of careful temj)erature observations. 



It is a well-established fact that the summer of 1877 was not so warm 

 as that of the i)receding year. It is also known that the catch of men- 

 haden in Maine for that year was much smaller than in 187G, when it 

 was unusually large. There may be a connection between these circum- 

 stances, though the observations of water temperatures at my disposal 

 are not sufficient to warrant decided geueralization. The means for the 

 summer months of 187G M'ere, at Eastport, 45°.5; at Portland, 57°.9 ; at 

 Wood's Holl, 70°.4 ; at New London, Gi ° ; at Norfolk, 78°.7. The corre- 

 sponding means for 1877 were, at Eastport, 42°.8; Portland, 57°.G; Wood's 

 Holl, C70.7 ; New London, GGo.9 ; and Norfolk, 77°.2. The summer of 



