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Atlantic salmon restoration in the Great Lakes as an example of species restoration Chris Wilson Aquatic Research Section Ontario Ministry of Natural Resources Salmo salar, “the leaper” • desired but vulnerable species • sensitive to: – habitat loss / degradation – over-exploitation • history = one long retreat – historical fisheries – high-value aquaculture global population decline photo credit: Eric Verspoor Historical Lake Ontario population • unknown if landlocked or anadromous • very little historical information available • multiple impacts resulted in 19th century loss (overharvest, dams, logging, pollution) extirpated in 1898 (COSEWIC 2006) extinct? (COSEWIC 2010, COSSARO 2011) Historical restoration attempts (1800s) Wilmot hatchery: 1866 - 1884 yearly stocking of eggs, fry, and yearling fish early signs of success, but steady decline of wild fish defeated by fishing and habitat pressures (dams, pollution, deforestation) www.bringbackthesalmon.ca Photo credit: Jason Mortlock LAKE ONTARIO ATLANTIC SALMON RESTORATION PROGRAM & PARTNERSHIP Components of restoration effort • • • • Fish production and stocking Research and assessment Habitat enhancement Education and outreach • 1st 5 years: – Credit River – Duffins Ck – Cobourg Ck Outreach and Education Identify life stage + habitat needs within a spatial-temporal framework 1-3 years (lake) • habitat needs (physical, thermal, chemical) • food requirements • competition • predation • other challenges 1-2 years (tribs) • information needs research / assessment Restoration options 1) identify + introduce closest surviving relatives (genetic similarity) 2) ecological suitability 3) introduce multiple strains with differing traits (experimental approach) follow-up assessment! ROM ID Number: 23235 (Krueger et al 1991, Meffe 1995, Moritz 1999, Jones 2003) Genetic tracking of restoration effort • 1st 5 year segment of 15 year restoration plan (2005-2020) • assess genetic ancestry of historical population (ROM) • matched-plant introductions of three ‘best bet’ source populations • genetic tracking of stocked individuals through strain and parentage analysis assess optimal life stage (+strain) for juvenile survival + adult returns Source populations Lac Saint-Jean Sebago (King et al 2001) LaHave • substantial genetic differences among three ‘best bet’ source populations enables multi-generational genetic tracking of stocked individuals through strain and parentage analysis Broodstock histories + genetic tracking LaHave 1st smolting of 2006 yearclass fry 12 20 11 20 09 20 08 20 07 20 06 20 05 20 19 89 yearlings 10 earliest date for adult returns from 2006 yearclass fingerlings 20 Strain / life stage broodstock spawning event Broodstock histories + genetic tracking LaHave Strain / life stage broodstock spawning event 1st smolting of 2006 yearclass earliest date for adult returns from 2006 yearclass Sebago 12 20 11 20 10 20 09 20 08 20 07 20 06 20 05 20 19 89 Lac St. Jean Restoration of Atlantic Salmon to Lake Ontario • matched-plant introductions of ‘best bet’ source populations • genetic tracking of stocked individuals – 3 strains – 3 life stages – identify to family • assess juvenile survival, growth and fitness (Russ Bobrowski, Trent M.Sc.) • [adult returns: identify most effective life stage + strain] Stocking source contributions to wild adults Comparative performance of stocked life stages 250 Cobourg Brook 200 N EEG • N Fry as EEG 150 N Yearling N Fall Fingerling 100 • N Fry 50 • 0 Smolt Adults Smolt 2009 Adults Smolt Adults 2010 2011 highly variable among years majority of smolts stocked as fry and yearlings returning adults stocked as fry Credit River 250 N EEG 200 N Fry as EEG • N Yearling 150 N Fall Fingerling • N Fry 100 50 0 Fall Juveniles 2009 Adults Fall Juveniles 2010 Adults Smolt Fall Juveniles 2011 Adults evidence for 2 years of residency all stocked life stages contribute to smolts and adults (2011 data) Ecological differences among strains NSERC Strategic: Western, Windsor, UQAM, OMNR (Neff, Heath, Pitcher, Peres-Neto, Wilson) • life history differences among strains in shared environment (growth and maturity) • behavioural differences in interactions with brown trout (S. trutta) and rainbow trout • differences in stress physiology among strains significant implications for probable fitness in wild testing fitness variation within and among sources under wild conditions Known challenges Ecological challenges • barriers for adult migration + spawning • changes to Lake Ontario ecosystem and aquatic communities –altered food web –prey fish abundance, stability, diversity –interactions with other salmonids (lake and stream environments) • effects of thiamine deficiency (multiple life stages) Social challenges • balancing diverse public interests and values • keeping the public interested, informed and engaged • understanding and meeting expectations of partners and sponsors Restoration of Atlantic Salmon to Lake Ontario • 2nd 5 year segment of 15 year restoration plan (2005-2020) • many known + unknown challenges still remain (all fronts) • employing genetic tracking to assess and inform management practices and effectiveness of restoration efforts • long-term exercise in adaptive management + restoration ecology LAKE ONTARIO ATLANTIC SALMON RESTORATION PROGRAM & PARTNERSHIP www.bringbackthesalmon.ca