. Commercial fisheries review. Fisheries; Fish trade. 18 ABUNDANCE 1920 1969 HIGHEST CISCO. SUCKER «?£=*â WALLEYE * Tfr ^ f. SUCKER <!w? CHANNEL LOWEST CATFISH â GOLDFISH BULLHEAD LOW-VALUE Fig, 3 - in 1920, the commercial catch from Lake Erie was dominated by five high-value f i sh es--cisco, blue pike, sugar, whitefish, and walleye. Now only the walleye is left, and it is in serious decline. The pressures of rapid environmental degradation and heavy e xplo i ta t ion have left us with a fishery resource composed only of medium and low-value fishes. heated discharges would disrupt spawni
. Commercial fisheries review. Fisheries; Fish trade. 18 ABUNDANCE 1920 1969 HIGHEST CISCO. SUCKER «?£=*â WALLEYE * Tfr ^ f. SUCKER <!w? CHANNEL LOWEST CATFISH â GOLDFISH BULLHEAD LOW-VALUE Fig, 3 - in 1920, the commercial catch from Lake Erie was dominated by five high-value f i sh es--cisco, blue pike, sugar, whitefish, and walleye. Now only the walleye is left, and it is in serious decline. The pressures of rapid environmental degradation and heavy e xplo i ta t ion have left us with a fishery resource composed only of medium and low-value fishes. heated discharges would disrupt spawning severely and could destroy incubating eggs. 3) BCF data show that an increase in in- cubation temperatures from 10 to 15° C, for example, will decrease incubation period of walleyes from 20 to 10 days. Quite possibly, unnatural heating in areas where eggs are in- cubating would result in unnaturally earlier hatching when environment could be unsuit- able to their survival. German scientists have demonstrated this for reduction of whitefish in Lake Constance, Switzerland. There should be no significant additional thermal inputs into Lake Erie, especially into western basin, under possible consequences have been assessed. Fishery Resources Of all Great Lakes, Lake Erie has been most fertile and productive in pounds of fish. Nineteen species have been significant in the landings at some time. Annual combined and Canadian production, which has fluctuated little in the past 50 years, has averaged about 50 million pounds. Lake Erie fish production, on a poundage basis, continues to maintain itself. However,. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original United States. National Marine Fisheries Service; U. S. Fish and Wildlife Service; United States. Bureau of Commericial Fisheries. [Washington]
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