and bottom types. Drag locations, by cruise, have 

 been plotted and are shown in Figures 2 and 3. 



Exploratory cruises are numbered consecutively 

 regardless of the area of operation; thus, the num- 

 bers designating Lake Erie cruises used in this paper 

 are not in sequence. 



Throughout this paper, a commercially significant 

 catch will be defined as those catches having a 

 gross ex-vessel value of $7.50 per '/2-hr fishing time. 

 The following Vi-hr catch rates are considered to be 

 commercially significant: yellow perch, 85 pounds; 

 rainbow smelt, 150 pounds; freshwater drum, 375 

 pounds; carp, 220 pounds; channel catfish, 35 

 pounds; and white bass, 50 pounds. 



FISHING EFFORT 



The four cruises, 1962 through 1966, included 

 fishing all three basins of Lake Erie. The operating 



time of 100 days accounted for 245 trawl drags (over 

 1 18 hr of fishing). To simplify further discussions, a 

 brief description of each cruise, the geographical 

 delineation of three basins of the lake, and the dis- 

 tribution of fishing effort follow. 



The first Lake Erie cruise of this study (Cruise 2 

 of the Kaho) covered the 26 days from 25 April to 

 20 May 1962; 56 experimental 30-min drags were 

 completed. 



Cruise 4 (the second Lake Erie cruise) covered 

 the 18 days from 23 September to 10 October 1962. 

 Sixty-two experimental drags were completed, 

 seven of which were made for the study of mesh- 

 size selectivity and are not discussed in this paper. 

 Three of the remaining 55 drags were cut short on 

 account of snags and rough bottom. 



Cruise 1 1 (the third Lake Erie cruise) covered the 

 29 days from 22 May to 20 June 1963. Eighty-seven 

 exploratory drags were completed, six of which 



LA« ERIE EmOMtlOHS 



Figure 2. — Fishing sites occupied by RV Kaho during 1962 

 Lake Erie explorations (Cruises 2 and 4). 



Figure 3 —Fishing sites occupied by RV Kaho during 1963 

 and 1966 Lake Erie explorations (Cruises 1 1 and 36). 



