Lake Erie Bottom Trawl Explorations, 1962-66 



EDGAR W. BOWMAN 1 



ABSTRACT 



The Bureau of Commercial Fisheries (now the National Marine Fisheries Service) Exploratory Fishing 

 and Gear Research Base, at Ann Arbor, Mich., surveyed the abundance, availability to the otter (bottom) 

 trawl, and depth distribution of various Lake Erie fish stocks between April 1962 and October 1966. The 

 four exploratory cruises, conducted aboard the research vessel Kaho, clearly demonstrated the effective- 

 ness of the bottom trawl in producing commercial quantities of yellow perch, Perca flavescens, and 

 rainbow smelt, Osmerus mordax. Freshwater drum, Aplodinotus grunniens; carp, Cyprinus carpio; 

 channel catfish, Ictalurus punctatus; and white bass, Roccus chrysops. were all produced in commercial 

 quantities at least once during the study and collectively accounted for 17. 1% of the total landings. 



Between the first exploratory cruise in 1962 and the last in 1966 the abundance of yellow perch 

 decreased significantly, and that of alewife, Alosa pseudoharengus, increased dramatically. 



INTRODUCTION 



A gradual population shift in Lake Erie fisheries 

 has led to commercial extinction of many highly 

 prized species. Lake herring, Coregonus artedii, has 

 ceased to be a factor in the commercial catch statis- 

 tics for Lake Erie after 1947 and can now be consid- 

 ered to be commercially extinct. Blue pike, 

 Stizostedion vitreum glaucum, have declined to the 

 point where in 1964 less than 500 pounds were re- 

 ported taken by U.S. and Canadian fishermen. The 

 population of sauger, S. canadense, declined drasti- 

 cally between 1946 and 1958 and may nowbenearing 

 biological extinction. For years annual production of 

 lake whitefish, Coregonus clupeaformis, fluctuated 

 between 1 and 7 million pounds but in 1955 landings 

 began to decline sharply. Less than 3,000 pounds 

 were landed by U.S. fishermen in 1966. 



In 1958, the Bureau of Commercial Fisheries 

 began exploratory fishing to find possible alternate 

 commercial species in Lake Erie; explorations 

 through 1959 demonstrated the effectiveness of the 

 bottom trawl in taking commercial quantities of 

 rainbow smelt, Osmerus mordax, and provided in- 

 formation concerning the distribution of smelt by 



'Exploratory Fishing and Gear Research Base, Bureau of 

 Commercial Fisheries, Ann Arbor, Mich.; present address: 

 Northeast Fisheries Center, National Marine Fisheries Service, 

 Woods Hole. MA 02543. 



area, season, and depth (Sand and Gordon, 1960). 

 Succeeding explorations in 1960 (Carr, 1964) added 

 to the 1958 and 1959 findings and indicated species 

 other than smelt were also available to bottom 

 trawls. 



During the period 1962-66, seven major food 

 species in Lake Erie made up the bulk of the annual 

 catch: walleye, Stizostedion vitreum vitreum; yellow 

 perch. Perca flavescens; rainbow smelt; freshwater 

 drum, Aplodinotus grunniens; white bass, Roccus 

 chrysops; channel catfish, Ictalurus punctatus; and 

 carp, Cyprinus carpio. 



This study is based on two exploratory cruises 

 undertaken in 1962 and one cruise each in 1963 and 

 1966. The data collected, together with previously 

 gathered data 1) document for the record the fishery 

 population available in Lake Erie between 1962 and 

 1966 and 2) offer a baseline for future comparison 

 studies of species abundance and composition. 



VESSEL, GEAR, AND METHODS 



The Department of the Interior research vessel 

 Kaho (Fig. 1) was used for all exploratory fishing 

 operations. Launched in 1961, the RV Kaho is of 

 steel and aluminum construction, is approximately 

 65 ft. long, has a 17%-ft beam and a loaded draft of 8 

 ft. The vessel is rigged for stern trawling and is 

 equipped with a "white line" echo sounder for defin- 

 ing bottom configurations and for detecting fish. 



