transforming in a shorter period, presumably because of reduced competition 

 for food and space. This requires more thorough surveys and more frequent 

 treatments and emphasizes the need for alternative controls. The commis- 

 sion is developing an integrated control program including permanent 

 barriers on selected streams and is sponsoring research into chemical 

 attractants and repellants as well as chemosterilants. 



1958 I9S9 I960 1961 1962 1963 1964 1965 1966 1967 1968 1969 1970 1971 1972 1973 1974 



Figure 6. Sea lamprey catch from eight streams tributary to 

 Lake Superior. Modified from Crowe, 1975. 



In 1971 comprehensive studies of the immediate and long-term effects of 

 lampricides in the environment were initiated. Results suggest that the 

 effects are ^ery small, that the chemical control program can continue, and 

 that registration of the lampricides by the Environmental Protection Agency 

 will be forthcoming upon completion of the required studies. About $1.2 

 million were allocated to do this registration-oriented research in 1971-74. 



The annual budget of the commission is about $4 million. Without con- 

 trol of sea lamprey the sport and commercial fisheries would be limited. 

 To date, with fish stocks only in the process of rehabilitation, the value 

 of the Great Lakes sport fishery is estimated at over $350 million. The 

 commercial fishery is valued at $19 million at the dock and approaches $100 

 million at the market. There is an excellent return from the money 

 invested in sea lamprey control. 



225 



