American Fisheries Society 433 



"As is well known, eels do not breed in our inland waters, 

 nor in the Baltic. Their spawning is done exclusively in the 

 ocean where the depth exceeds 1000 meters (3280 ft.) and 

 at places where, even at these great depths, a temperature 

 not lower than 7° C. (44° F.) prevails. The spawning 

 grounds of the eel that are of greatest importance to us lie 

 off the west coast of the European Continent — off the 

 British and French west coasts and the coast of northern 

 Spain, at the point where the great plateau on which the 

 North European continent stands, falls off sharply into the 

 Atlantic basin and reaches depths exceeding 1000 meters. 

 Especially important spawning grounds of the eel appear to 

 lie southwesterly from Ireland and the mouth of the 

 Bristol Channel. To these spawning grounds resort ap- 

 parently all the eels grown in German waters and emigrat- 

 ing from the same every year, in anticipation of the ripen- 

 ing of their sexual products. From these remote spawning 

 grounds, then, must the young fry retrace the whole long 

 road back in order to enter our German waters. If. in spite 

 of this immense distance, large numbers of eel-fry appear 

 every year in the lower courses of our German rivers, the 

 fact shows that the reproduction of the eel on its spawning 

 grounds must be on an immense scale. Nevertheless if a 

 slow but steady decrease in the catch of eels in our waters 

 appears to have set in, it would indicate that there was a 

 decrease in the immensity of the eel-fry immigration. 



"In our waters themselves there existed increased diffi- 

 culties for the ascent of the eel-fry, in this way, that the 

 dams, which were formerly of inferior construction and 

 gave the ascending eel-fry many an opportunity to slip 

 through, have been so much improved by rebuilding that 

 the surmounting of these dams is made completely im- 

 possible for eel-fry. We must confidently expect a decline 

 more and more rapid of the product of our eel-fisheries 

 unless measures are taken immediately for a plentiful stock- 

 ing of our waters with eel-fry. This can be done and is 

 done at many places in two ways; first by the construction 



