| Abstract: | We assessed the reproductive potential of various genetic strains of hatchery lake trout (Salvelinus namaycush) in southern and eastern Lake Ontario from indices of fecundity and indices of male abundance. Indices were constructed from catches of mature lake trout in gill nets during September 1980 to 1994 after correcting for mortality from sea lampreys (Petromyzon marinus) which occurred between September sampling and late fall spawning. Strain and age were assigned to individual lake trout based on clipped fins and maxillary bones or coded wire tags. Fecundity-length relationships for fish of the same age, determined from mature females collected in 1977 to 1981 and 1994, were not different (P > 0.05) among genetic strains. For all strains combined, fecundity-length relationships in 1977 to 1981 were not different among fish of various ages but in 1994, age-5 and -6 fish had fewer eggs (P < 0.003) than age-7 fish, and age-7 fish had fewer eggs (P < 0.003) than fish of age 8, 9, or 10. Annual indices of fecundity varied 19 fold and indices of mature males varied 11 fold; both indices were low in the early 1980s, increased sharply in the mid 1980s, and peaked in 1993. The strain which dominated fecundity and mature male indices shifted during the study from Seneca Lake strain to Lake Superior strain and then back to Seneca Lake strain. However, changes in either reproductive potential or genotypes do not appear responsible for the abrupt appearance of naturally-produced yearling lake trout throughout southern and eastern Lake Ontario in 1994-1995, the first widespread occurrence of juveniles produced by hatchery lake trout in Lake Ontario. |
| Genre: | Article |
| ProdID: | 1000761 |
| Citation Author: | O'Gorman, Robert; Elrod, Joseph H.; Schneider, Clifford P. |
| Citation Contributing Office: | Great Lakes Science Center |
| Citation Datum: | |
| Citation Day: | |
| Citation Edition: | |
| Citation Editor: | |
| Citation End Page: | 144 |
| Citation Issue: | 1 |
| Citation Keywords: | |
| Citation Language: | English |
| Citation Larger Work Title: | Journal of Great Lakes Research |
| Citation LatN: | |
| Citation LatS: | |
| Citation LonE: | |
| Citation LonW: | |
| Citation Month: | |
| Citation No Pagination: | |
| Citation Number Of Pages: | 13 |
| Citation Online Only Flag: | |
| Citation Phsyical Description: | p. 131-144 |
| Citation Projection: | |
| Citation Public Comments: | |
| Citation Publisher: | |
| Citation Series: | |
| Citation Series Code: | |
| Citation Series Number: | |
| Citation Search Results Text: | Reproductive potential and fecundity of lake trout strains in southern and eastern waters of Lake Ontario, 1977-1994; 1998; Article; Journal; Journal of Great Lakes Research; O‘Gorman, Robert; Elrod, Joseph H.; Schneider, Clifford P. |
| Citation Start Page: | 131 |
| Citation Volume: | 24 |
| Citation Year: | 1998 |
| Type: | citation/reference |
| Text: | Reproductive potential and fecundity of lake trout strains in southern and eastern waters of Lake Ontario, 1977-1994; 1998; Article; Journal; Journal of Great Lakes Research; O‘Gorman, Robert; Elrod, Joseph H.; Schneider, Clifford P. |
| URL (THUMBNAIL): | http://pubs.er.usgs.gov/thumbnails/outside_thumb.jpg |
| Date Other: | Thu, 1 Jan 1998 00:00 -0600 |
| Publisher: | |
