| Abstract: | Discrepancies between ages determined from otoliths and those determined from scales were common and, sometimes, quite large in alewives Alosa pseudoharengus collected in fall 1983 from Lakes Ontario, Huron, and Michigan. Among fish with ‘otolith ages‘ of 4 or more, the percentages having identical ‘scale ages‘ were 1% in Lake Ontario, 35% in Lake Huron, and 56% in Lake Michigan. Among alewives with different otolith and scale ages, the percentages with discrepancies of 3 years or more were 51% in Lake Ontario, 23% in Lake Huron, and 6% in Lake Michigan. Among the three populations, variation in the magnitude of age disagreements were perhaps due to the different mortality rates in each lake, whereas variation in the frequency of disagreements appeared to be due to different ratios of food to fish in each lake. Previously reported age compositions and rates of mortality and production for Great Lakes alewives derived from scales have probably been inaccurate to various degrees. |
| Genre: | Book chapter |
| ProdID: | 81431 |
| Citation Author: | O'Gorman, Robert; Barwick, D. Hugh; Bowen, Charles A. |
| Citation Contributing Office: | Great Lakes Science Center |
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| Citation Editor: | Summerfelt, R. D.; Hall, G. E. |
| Citation End Page: | 210 |
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| Citation Language: | English |
| Citation Larger Work Title: | Age and growth of fish |
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| Citation Phsyical Description: | p. 203-210 |
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| Citation Publisher: | Iowa State University Press |
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| Citation Search Results Text: | Discrepancies between ages determined from scales and otoliths for alewives from the Great Lakes; 1987; Book chapter; BOOK; Age and growth of fish; O‘Gorman, Robert; Barwick, D. Hugh; Bowen, Charles A. |
| Citation Start Page: | 203 |
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| Citation Year: | 1987 |
| Type: | citation/reference |
| Text: | Discrepancies between ages determined from scales and otoliths for alewives from the Great Lakes; 1987; Book chapter; BOOK; Age and growth of fish; O‘Gorman, Robert; Barwick, D. Hugh; Bowen, Charles A. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1987 00:00 -0600 |
| Publisher: | Iowa State University Press |
