Lake Trout Rehabilitation in Lake Huron

Predation on emergent lake trout fry in Lake Champlain

“…Although the events leading to the extirpation of lake trout from the lower four Great Lakes in the 1960s are understood, causes of the decline and disappearance of this species in Lake Champlain by 1900 are unclear (Ellrott and Marsden, 2004). Thus far, efforts to reestablish self-sustaining populations in the lower four Great Lakes and Lake Champlain have resulted in limited success (Cornelius et al, 1995;Elrod et al, 1995;Eshenroder et al, 1995;Holey et al, 1995;Reid et al, 2001;Ellrott and Marsden, 2004). In Lake Champlain, high fry densities have been measured at several reefs, but naturally-recruited juveniles and adults (identified by having a fin clipped) are rare to absent.…”

Heritage strain and diet of wild young of year and yearling lake trout in the main basin of Lake Huron

“…The Seneca Lake strain has been linked to the appearance of naturally produced lake trout in Lake Ontario (Marsden et al 1989, but also see O'Gorman et al 1998a. The success of the Seneca Lake strain has been linked to its early development (Horns 1985), age of maturity and depth preference (Eshenroder et al 1995), as well as resistance to lamprey-induced mortality (Schneider et al 1996).…”

“…Lake trout were extirpated between 1945 and 1955 and subsequent restoration efforts have included sea lamprey Petromyzon marinus control, gear restrictions, harvest quotas, stocking of hatchery-reared fish, and designation of biological refuges for lake trout reproduction (Eshenroder et al 1995). Studies to evaluate the success of lake trout restoration efforts are listed as research priorities by all management agencies in the Great Lakes region (Eshenroder et al 1999).…”

“…Although stocked fish support substantive recreational, commercial, and subsistence fisheries, the goal of self-sustaining lake trout populations remained elusive, primarily because of chronic recruitment failure of naturally reproduced fish as evidenced by predominance (N96%) of marked hatchery fish in agency surveys. Reasons for recruitment failure were not known, but hypotheses included the vulnerability of lake trout eggs and/or fry to predation (Savino and Henry 1991;Chotkowski and Marsden 1999;Biga et al 1998;Horns and Magnuson 1981), alewife suppression, contaminants, and inability of hatchery fish to identify historic spawning sites or engage in successful spawning behavior (Eshenroder et al 1995).…”

Sea lamprey wounding in Canadian waters of Lake Huron from 2000 to 2009: Temporal changes differ among regions

“…Diporeia was a staple food source for lake whitefish (Coregonus clupeaformis) and its decline caused a significant decrease in whitefish condition and growth (Madenjian et al, 2006;McNickle et al, 2006;Rennie et al, 2009). For lake trout (Salvelinus namaycush), who were virtually extirpated from the lake in the 1960s due to sea lamprey (Petromyzon marinus) parasitism , a rehabilitation effort which has been in place since the 1970s (Eshenroder et al, 1995) appears to be succeeding (Morbey et al, 2008;Riley et al, 2007). However, despite increases in natural reproduction, lake trout underwent a 21% decline in energy density from 1995 to 2004 (Paterson et al, 2009) and showed a decline in growth and condition (He et al, 2008;He and Bence, 2007).…”