Lake Trout Status in the Main Basin of Lake Huron, 1973–2010

Autor: He, JiX., Ebener, MarkP., Riley, StephenC., Cottrill, Adam, Kowalski, Adam, Koproski, Scott, Mohr, Lloyd, Johnson, JamesE.
Zdroj: North American Journal of Fisheries Management; April 2012, Vol. 32 Issue: 2 p402-412, 11p
Abstrakt: AbstractWe developed indices of lake trout Salvelinus namaycushstatus in the main basin of Lake Huron (1973–2010) to understand increases in the relative abundance of wild year-classes during 1995–2010. Sea lamprey Petromyzon marinuswounds per 100 lake trout declined from 23.63 in 2000 to 5.86–10.64 in 2002–2010. The average age-7 lake trout catch per effort per recruitment (CPE/R; fish·305 m of gill net−1·million stocked yearlings−1) increased from 0.56 for the 1973–1990 year-classes to 0.92 for the 1991–2001 year-classes. Total CPE (fish/305 m of gill net) declined from 16.4 fish in 1996 to 4.1 fish in 2010, but the percentage of age-5 and younger lake trout steadily decreased from more than 70% before 1996 to less than 10% by 2009. The modal age in gill-net catches increased from age 5 before 1996 to age 7 by 2005. The average adult CPE increased from 2.8 fish/305 m of gill net during 1978–1995 to 5.34 fish/305 m of gill net during 1996–2010. The 1995–2010 year-classes of wild fish were more abundant than previous year-classes and were associated with the relatively high adult abundance during 1996–2010. Until the 2002 year-class, there was no decline in age-7 CPE/R; until 2008, there was no decline in adult CPE. Low survival of the 2002 and 2003 year-classes of stocked fish was related to the event of alewife Alosa pseudoharenguspopulation collapse in 2003–2004. Lake trout in the main basin of Lake Huron are undergoing a transition from a hatchery stock to a wild stock, accompanied by an increased uncertainty in delayed recruitment. Future management should pay more attention to the protection of wild recruitment and the abundance of the spawning stock.Received April 20, 2011; accepted December 30, 2011
Databáze: Supplemental Index
Externí odkaz: