40 Artificial Aquatic Habitats 



larger or smaller. One is forced to conclude that lake size alone has little 

 significance as an index of productivity and that the water quality, the 

 conformation of the lake basin, and the length of shoreline are much 

 more important. Shallow lakes are more productive than deeper ones ^^' ^^ 

 because the most productive zone is that influenced by the sun's rays. 

 Where this layer is in contact with the lake bottom, one may expect to 

 reach a high level of production. Other factors, such as the length of the 

 growing season ^^ also influence productivity. 



LITERATURE 



1. Anon., Ann. Repts. of the Upper Mississippi River Conservation Commit- 

 tee (Mimeo), 1944-1961. 



2. Bardach, J. E., Hydrohiologia, 7(4), 309-324 (1955). 



3. Bennett, G. W., 7/7. Wildl, 1(2), 8-10 (1946). 



4. Bennett, G. W., 7//. Nat. Hist. Surv. Bull, 26(2), 217-276 (1954). 



5. Bennett, G. W., and Durham, L., 7//. Nat. Hist. Surv. Biol. Notes, 23, 1-16 

 (1951). 



6. Carlander, K. D., Jour. Fish. Bes. Bd. Can., 12(4), 543-570 (1955). 



7. Davidson, V. E., and Johnson, J. A., U.S.D.A. Farmers Bull, 1938, 1-22 

 (1943). 



8. Grim, J., Allg. Fisch-Ztg., Jahrg., 77(14), 281-283 (1952). 



9. Hansen, D. F., 7//. State Acad. ScL Trans., 35, 197-204 (1942). 



10. Hasler, A. D., and Einsele, W. G., N. A. Wildl Conf. Trans., 13, 527-555 

 (1948). 



11. Hayes, F. R., Jour. Fish. Res. Bd. Can., 14(1), 1-32 (1957). 



12. Hooper, F. F., Ball, R. C, and Tanner, H. A., Am. Fish. Soc. Trans., 82, 

 222-241 (1953). 



13. Humphrys, C. R., and Veatch, J. C, Mich. Sta. Uni. Ag. Exp. Sta. Water 

 Bull, 8, 1-18 (1961). 



14. Hutchison, G. E., "A Treatise on Limnology," Vol. 1, 1015 pp. New York, 

 J. Wiley & Sons, 1957. 



15. Jackson, H. O., and Starrett, W. C, Jour. Wildl Mgt., 23(2), 157-168 

 (1959). 



16. Jenkins, R. M., Proc. Okla. Acad. ScL, 38, 157-172 (1958). 



17. King, W., U.S.F.&W. Circ, 86, 1-20 (1960). 



18. Maupin, J. K., Wells, J. R., Jr., and Leist, Claude, Kan. Acad, of Set. 

 Trans., 57, 164-171 (1954). 



19. Meehean, O. L., Jour. Wildl Mgt., 16(3), 234-237 (1952). 



20. Moyle, J. B., Am. Fish. Soc. Trans., 76, 322-334 (1949). 



21. Parsons, J. D., 7//. Acad. ScL Trans., 50, 49-59 (1958). 



22. Parsons, J. W., Am. Fish. Soc. Trans., 85, 75-92 (1957). 



23. Pfitzer, D. W., N. A. Wildl Conf. Trans., 19, 271-282 (1954). 



24. Powers, E. B., Shields, A. R., and Hickman, M. A., Jour. Tenn. Acad. 

 ScL, 14(2), 239-260 (1939). 



25. Rounsefell, G. A., Copeia, 1946(1), 29-40 (1946). 



26. Ruttner, F., "Fundamentals of Limnology," Univ. of Toronto Press, 

 Toronto, Ont., Can., 1953. 



