| Abstract: | The sex composition and other biological characteristics of the bloater changed substantially during recent decades of continuous ecological change in Lake Michigan. The percentages of females increased from 72% of the bloaters samples in 1928-32 to 95% in 1963, and ranged from 94 to 97% in 1964-69. The unusual predominance of females was established at an early age, unquestionably before age III. Bloaters grew faster in southeastern Lake Michigan in 1960-69 than in 1954 and earlier, and were less abundant there in 1966-69 than in 1962-65. The average age of female bloaters from trawls increased from 3.5 years in 1964 to 6.0 years in 1969. The increase in average age followed a heavy drop in fishing intensity and was accompanied by a decline in recruitment. The percentage representation of age-III bloaters, for example, decreased from 62.4% in 1964 to 2.5% in 1969. The changes in biological characteristics of the bloater may partly be symptoms of a fish population that is poorly adjusted to the changing ecology of Lake Michigan. |
| Genre: | Book chapter |
| ProdID: | 81412 |
| Citation Author: | Brown, Edward H., Jr. |
| Citation Contributing Office: | Great Lakes Science Center |
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| Citation Editor: | Lindsey, C. C.; Woods, C. S. |
| Citation End Page: | 514 |
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| Citation Language: | English |
| Citation Larger Work Title: | Biology of coregonid fishes |
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| Citation Phsyical Description: | p. 501-514 |
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| Citation Publisher: | Univ of Manitoba Press |
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| Citation Search Results Text: | Extreme female predominance in the bloater (Coregonus hoyi) of Lake Michigan in the 1960‘s; 1970; Book chapter; BOOK; Biology of coregonid fishes; Brown, Edward H., Jr. |
| Citation Start Page: | 501 |
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| Citation Year: | 1970 |
| Type: | citation/reference |
| Text: | Extreme female predominance in the bloater (Coregonus hoyi) of Lake Michigan in the 1960‘s; 1970; Book chapter; BOOK; Biology of coregonid fishes; Brown, Edward H., Jr. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1970 00:00 -0600 |
| Publisher: | Univ of Manitoba Press |
