480 U.S. BUREAU OF FISHERIES 



hatching boxes in the marine hatcheries. The scrim rots rapidly 

 due probably to bacteria contained in the natural waters used. This 

 involves not only considerable expense for scrim but a heavy labor 

 cost and depreciation of boxes. The Division of Fishery Industries 

 has developed a preservative for vegetable fiber which is essentially 

 chrome tannage. In preliminary tests of 1933 this preservative 

 treatment indicated that the life of scrim in egg boxes could be 

 materially increased. Large scale tests are now in progress at four 

 hatcheries with several qualities of the chrome tanned scrim. 



DISTRIBUTION IN NATIONAL PARKS AND NATIONAL FORESTS 



Through cooperation of the United States Forest Service and the 

 personnel of the Bureau's Salt Lake City office there has been worked 

 out a definite program or policy of planting fish in national parks 

 and national forests in the West. On the basis of surveys made by 

 the Bureau's employees and with information provided by the forest 

 rangers the Salt Lake City office has been able to make up a definite 

 outline covering the species, size, and number of fish to be planted in 

 those waters of the public domain. The program covers not only 

 the fish provided by Federal hatcheries but in many instances those 

 furnished from State hatcheries. It has been found in many cases 

 that the supply of fish is insufficient to permit stocking to the extent 

 called for by the program. However, it is now known that such fish 

 as are planted are afforded the greatest possible chance of thriving 

 and are distributed in accordance with the capacity of the streams 

 to carry them as well as the demands of the fishermen. 



DESTRUCTIVENESS OF SPIDERS 



Observations made by the foreman of the Tishomingo (Okla.) 

 station have shown clearly that spiders, apparently having a semi- 

 aquatic habitat, can be and are responsible for a considerable loss of 

 fish. It was shown that these spiders attacked and killed channel 

 catfish fingerlings up to 2 inches in length. No definite information 

 is available to show the full extent of the loss from this source at 

 Tishomingo or whether the condition is prevalent elsewhere. Fidly 

 satisfactory means of control were not worked out but it is evident 

 that clearing the grass and similar growth along pond banks in which 

 the spiders live, will tend to limit the loss. 



COOPERATIVE FISH CULTURE WITH MUNICIPALITIES 



In the past the Bureau has cooperated with sportsmen's organiza- 

 tions in the conduct of rearing ponds, nurseries, etc., and has extended 

 this work to collaborate with governmental units, specifically with one 

 of the counties in Michigan. The idea has now been developed to a 

 further point at Rochester, N.Y. In Monroe County, in which the 

 city of Rochester is located, there arc a number of lakes included in 

 the park system which are suitable for the propagation of bass and 

 other fish. Recognizing the desirability of utilizing recreational areas 

 for the provision of additional recreation in the form of an adequate 

 stock of fish to be more widely distributed, the cooperation of the Bureau 

 was sought. In collaboration with the Izaak Walton League, the 

 city of Rochester, Monroe County, and the New York State Conserva- 



