52 BULLETIN OF' THE BUREAU OF FISHERIES. 



a strong current. In the low water of summer a mule is of no avail; at this season of 

 the year a cable 400 to 500 yards in length is used, one end of which is anchored down 

 the river, while the other is hauled through a pulley by means of a two-horsepower 

 gasoline engine, located near the center of the barge. The engine is also employed 

 to assist in raising the bars from the mussel beds. The barge is towed from place to 

 place by a small gasoline boat alongside or at the stem. By this method three men 

 have been known to gather 3 tons of shells in a day in favorable localities in the Ohio 

 River. 



Advantages and Disadvantages of the Method. — Except where snags are preva- 

 lent, good success is had with the bar and crowfoot under a wide variety of conditions. The 

 daily catch probably averages less than 500 pounds of marketable shells. In severely 

 depleted regions only 100 to 200 pounds may be taken, while a half ton or more may 

 reward the fisherman in better localities. The fishermen claim that the mussels or clams 

 bite best in the spring of the year, on rising water, and early in the morning. 



A serviceable John boat could be made in 1914 at a cost of from $10 to $15; and 

 the bars, hooks, and lines at from $5 to $6 per pair; the necessary ropes cost from $2 

 to $3, making a total of from $17 to $24. However, if an engine of suitable power is 

 installed in the boat an additional amount of about $50 to $100 should be added to 

 the above sum. On the basis of the prices of materials in 191 9, these costs appear 

 approximately as follows: Boat, $23; bar, hooks, and lines, $10; ropes, $3; total, 

 excluding boat engine, $36. 



The method has these advantages: It is inexpensive, and not necessarily laborious; 

 it is adapted fof use in deeper waters where the hand rake or the tongs can not be used 

 successfully, and it can be employed readily by the inexperienced. 



The disadvantages of the crowfoot are not so obvious but are very important 

 nevertheless : 



1 . The mussel beds are repeatedly dragged over by hundreds and thousands of hooks, 

 with consequent possible injury to the mussels, especially the young. Gravid mussels, 

 it is known, will often abort the immature spawn when disturbed. 



2. Some mussels, after taking on the hooks, are pulled off while yet on the bottom 

 with more or less injury. Experiments conducted at the Fairport station indicate that 

 a large percentage of such mussels receive injuries from which they die. A considerable 

 number of mussels were taken by hooks and by rakes; each set of mussels was divided 

 into four lots, which were carefully balanced against one another in experimental ponds. 

 After two months 38 per cent of the crowfooted mussels and only 5 per cent of the 

 raked mussels had died. 



3. The hooks take exceedingly small mussels, even down to 0.75 to i inch in length, 

 which are not only useless for any economic purpose but are liable to a heightened mor- 

 tality when thrown back into the river. The use of larger wire for the hook has been sug- 

 gested, wath a view to lessening the number of small mussels taken. 



There are two or three designs of patented hooks on the market, and it is claimed that 

 they have advantages over the ordinary kinds made by the mussel fishermen. One 

 design, invented by the late J. F. Boepple, is like the ordinary twisted-wire hook, except 

 that the wire prongs are compressed near the tips and finally expanded to form a ball or 

 globular tip larger than the diameter of the wire. When the ball enters the opening of the 

 mussel, the shell closes on the compressed neck, and it is very difficult for the mussel 



