PROGRESS IN BIOLOGICAL INQUIRIES, 19 3 2 119 



East Tawas, Ossincke, Alpena, and Cheboygan on Lake Huron and 

 at Bervort, Epoiifotte, Naubinway, Cozy Harbor (Scotts Point), and 

 Manistique on Lake Michigan, and at Escanaba and Marinette on 

 Green Bay. 



The data collected during the 2 years have been compiled and 

 analyzed and show briefly the following facts that are pertinent to 

 legislative recommendations : 



1. The number of deep trap nets employed was larger in 1932 than 

 in 1931. 



2. The average number of both legal and illegal whitefish per lift 

 w^as less in 1932 than in 1931 at those ports where lifts were observed 

 from nets with the same size mesh set in the same depth of water and 

 Ufted on comparable dates in the 2 years. 



3. Both the average total length and the average weight of the 

 legal sized whitefish decreased slightly in 1932 as compared with 

 corresponding averages in 1931. 



4. The distribution by depth of water of both legal and illegal sized 

 whitefish was practically the same for the 2 years — the illegal sized 

 fish being most numerous in water from 81 to 109 feet in depth, while 

 the legal sized fish were most numerous in water deeper than 110 feet. 



5. The deep trap nets now in use have hfting pots with meshes 

 ranging from 3/2 to 5 inches in length, stretched measure. 



6. In 1932 a wholesale transfer of deep trap nets occured from 

 certain fishing grounds, long famous for its whitefish production, to 

 new^ grounds, due to the paucity of whitefish on the old established 

 grounds. 



On the basis of the above facts the following regulations w^ere pro- 

 posed for the fishing of deep trap nets in Michigan waters : (a) Limit 

 the depth of water in which these nets may be fished to 80 feet and 

 less; (6) require the minimum size of meshes in the lifting pot to be 

 4:% inches in length, stretched measure, as found in use permitting 

 a smaller mesh, not to exceed 2% inches, in one side of the pot for 

 the purpose of shoaling fish. 



STUDIES IN LAKE ERIE 



Telloio perch. — A preliminary paper was published by Frank W. 

 Jobes on the age and growth of the yellow perch of Lake Erie. The 

 study was based on some 1,179 specimens taken in 1927 and 1928. 

 Mr. Jobes found that the ages of these perch ranged from 1 to 6 

 years and that the year class of 1926 dominated the catch in both 

 1927 and 1928. Males and females grew in length at approximately 

 the same rates during the first 4 years, with the exception that the 

 females of the 1925 year class apparently grew significantly faster 

 than the males in their third year — the summer of 1927. Tlie most 

 rapid growth occurred during the first 2 years with a sharp decline in 

 growth rate during the third and a more gradual decline during the 

 fourth year of hfe. The sharp decline in the growth rate during the 

 third year may be associated w4th the attainment of sexual maturity. 

 The yellow perch of Lake Erie require 4 years to reach a total length 

 of 9 inches, the highest legal length limit for perch on the Great Lakes. 



Other species. — Age determinations and length computations from 

 scales have been completed for all the ciscoes and whitefish collected 

 on Lake Erie during the years 1927 to 1931, inclusive. During the 



