indicate that fish stocks in the area are sorely reduced, somewhat almost 

 to the point of disappearance. A decline in the sea lamprey population 

 would be a natural sequel to the recently observed abrupt decline of avail- 

 able prey species. 



As a matter of historical interest and as an aid in predicting the 

 future status of this parasite in Lakes Michigan and Superior, all available 

 records of the spawning runs entering the Ocqueoc River are assembled 

 herewith. (This run was first observed and reported in 1937 by Conservation 

 Officer Marvin Norton according to Shetter (I9h9) . 



Year Numbers trapped or 



enumerated 



19hh 1/ 3,366 



19 h$ y U,6o8 

 19ii6 (NO DATA) 



19 hi 2/ 10,000 



19U8 2/ 13,000 



19h9 1/ 2U,6U3 



1950 18,882 



Lake Michigan . — Whereas the population in Lake Huron appears to have 

 at least leveled off, Wisconsin Conservation Department reports for Hibbard 

 Creek in Door County reflect a near trebling of the population in north- 

 western Lake Michigai over 19U9 levels . This point is illustrated 

 in the following records of weir and trap catches of spawning migrants 3/ in 

 the afore-mentioned stream over a U-year period. 



1/ Shetter (19li9); partial capture of run; examination of Shetter' s data 

 suggests that these catches represent about three-quarters of the run enter- 

 ing in each year. 



2/ -kpplegate (193>0); data for 19h7 and 19^8 are estimates from counts of 

 total number of nests in watershed with consideration given for observed 

 spawning habits and sex ratio in those years; catch in 19U9 is entire run 

 taken in new permanent-type Ocqueoc River weir and trap. 



3/ Data for \9h$-\9\\b provided by Mr. Matt Patterson of the Wisconsin Con- 

 servation Department. The number of lampreys trapped in 19U5 is not the 

 complete run into the stream; trapping operations were intermittent in that 

 year. 



3/ Data for 19^7-19^9 extracted from Wisconsin's report in the "Report 

 of the Great Lakes Sea Lamprey Committee- 19^7 ," "Report of the Great 

 Lakes Sea Lamprey Committee-19li8/' and "Report of the Great Lakes Sea 

 Lamprey Committee-19li9, " (Mimeographed). 



8 



