GENERAL INTRODUCTION 



Charles J. Fish, Director 

 Buffalo Museum of Science 



The serious decline in certain fish populations 

 in Lake Erie has made obvious the need for more ex- 

 tended knowledge of conditions affecting the fishery. 

 To quote from a preliminary report (Fish et al. 1929): 

 "For several years the rapid decUne in the fish sup- 

 ply of the Great Lakes, particularly of Lake Erie, has 

 been a matter of serious concern not only to the fish- 

 ermen but to the American and Canadian govern- 

 ments, the states bordering on the lakes, and the 

 many private organizations and individuals interested 

 in preserving what was once one of the most pro- 

 ductive bodies of water in the world. 



"Obviously legislative action was necessary, but 

 the problem is an international one, and intelligent 

 legislation was not possible so long as the factors re- 

 sponsible for the decline were not known. Various 

 explanations were advanced. Some claimed that 

 Lake Erie was being overfished; others that chemical 

 and sewage wastes from the cities were polluting the 

 waters to such an extent that the fish were being 

 wiped out. Some fishermen attributed the decline 

 to sewage silt invading the spawning grounds and 

 rendering whole areas unfit for the production of 

 young fish. The possibility that a lack of food was 

 responsible for the decline was also advanced. But 

 so long as these claims remained unanswered there 

 could be little grounds upon which to base restric - 

 tive legislation. 



"Of one thing all are certain: the decline is 

 due to man's influence, but how? As a large shal- 

 low lake Erie offers the greatest possibilities for rich 

 animal and plant life; in fact, there is no lake in the 

 world more favorable for the production of fish than 

 this body of water under its normal conditions; and 

 the records bear out this statement. One has only 

 to refer to the large catches of former years to learn 

 what a varied and extensive fish fauna Lake Erie is 

 capable of supporting. " 



Lake Erie, with a drainage area of 34, 680 

 square miles and a continuous movement of water, 

 offers unusual biological possibilities. A portion of 

 the lake retains cold bottom water throughout the 



year, while the remainder, which constitutes a 

 large percentage of the total area, offers con- 

 ditions favorable for shallow water species requir- 

 ing high summer temperatures. It is the shallowest 

 of the Great Lakes, and is 240 miles long with an 

 average width of about 40 miles. Having a total 

 area of approximately 9, 633 square miles (exclu- 

 sive of rivers), the lake divides itself into three 

 natural sections (fig. 1). 



The western section, which comprises less than 

 one -eighth of the total area, has a maximum depth 

 of 15 meters. A natural barrier formed by points ex- 

 tending from the two shores and two islands (Kelly 

 Island and Pelee Island) separates this body of water 

 from the rest of the lake. The waters of the Detroit, 

 Maumee, and Sandusky rivers enter the lake in this 

 area. 



The middle two-thirds of the lake forms a second 

 section extending from the islands to a shoal having 

 a minimum depth of 13 meters and extending north 

 and south across the lake just west of the 25 -meter 

 contour line, in the vicinity of Erie, Pa. This area, 

 the widest part of the lake, forms a broad shallow 

 basin with a maximum depth of 26 meters in its 

 western portion. The greater part of the floor, some- 

 times referred to as the Great Plain, is exceptionally 

 even. No major rivers enter here. 



The eastern, or deep section, comprises the area 

 investigated in 1928 and extends from Erie, Pa. to 

 the entrance to the Niagara River. The most signif- 

 icant characteristics are the Deep Hole, having a 

 maximum depth of 64 meters, and Long Point which 

 exerts great influence on the circulation of the water 

 mass in the eastern part of the lake. This point forms 

 a shallow bay 15 miles wide at the mouth and some 

 20 miles in length, with a maximum depth of about 

 14 meters. 



The Deep Hole is about 30 miles long and 20 miles 

 wide at the 40 -meter level. The bottom waters here 

 are only slightly influenced by summer warming, that 

 portion below 60 meters rarely attaining 5° C. 



The bathymetrical chart (fig. 1) shows the bottom 

 contours of Lake Erie. The approximate areas at the 

 various levels and their percentage of the total sur- 

 face area are given in table 1. 



