**ABSTRACT NOT FOR CITATION WITHOUT AUTHOR PERMISSION. The title, authors, and abstract for this completion report are provided below.  For a copy of the full completion report, please contact the author via e-mail at tomstewart54321@gmail.com. Questions? Contact the GLFC via email at frp@glfc.org or via telephone at 734-662-3209.**

Installation and operation of a resistance board weird in duffins creek, lake ontario to support atlantic salmon restoration

Tom Stewart¹, Chris Wilson², Marc Desjardins³, Jim Bowlby⁴, Christine Tu⁵

¹ 39 Elm Street, Kingston, Ontario, K7K 1M8

² Ontario Ministry of Natural Resources and Forestry, Trent University 1600 West Bank Drive, Peterborough, Ontario, K9L 0G2

³ Ontario Ministry of Natural Resources and Forestry, Lake Ontario Management Unit, RR#4, Picton, Ontario, K0K 2T0

⁴ 540 Bond Road, Milford Ontario, K0K 2P05

⁵ Toronto and Region Conservation Authority, 5 Shoreham Drive, Downsview, Ontario, M3N 1S4

December 2016

ABSTRACT:

Atlantic salmon (Salmo salar) were extirpated from Lake Ontario in the late 19th century and a renewed restoration program was initiated in 2006. Three strains of Atlantic salmon were stocked, originating from the LaHave River, Nova Scotia; Lac Saint-Jean (River Aux Saumons, Quebec); and Sebago (Maine). Hatchery fish were released as either spring fingerlings (swim-up and advanced stages, ~4 months old), fall-fingerlings (~11 months old) or spring yearlings (~16 months old). Capturing surviving adult salmon was difficult and a permanent weir and fishway was available on only one of three rehabilitation tributaries. In this study, a temporary resistance board weir, a technology new to the Great Lakes, was installed and operated during 2013-2015 on Duffins Creek, Lake Ontario to capture adult Atlantic salmon and evaluate performance of the different strains and life-stages stocked. The weir proved to be a very effective method to live capture all species of tributary spawning fish with catches ranging from 462 to 2351 fish/year. The weir operated under variable flows and withstood extreme weather events. Fish mortality, some of which was directly attributed to the weir, was highest (11.4%) during the first year. Modifications to operational procedures reduced mortality to 4.5-5.6% in subsequent years. Only 21 Atlantic salmon were captured (5-8 fish/year) and this likely reflects poor stocked fish survival rather than weir capture efficacy. Genetic parentage analysis was completed on 19 of the 21 captured Atlantic salmon adults. Although no adults from the Lac Saint-Jean strain were observed, this was expected as production stocking of this strain only began in 2013. The captured adults were a mix of LaHave strain (8 fish) and Sebago strain (9 fish), as well as two adults that showed equal assignment probabilities to both strains. The mixed-ancestry assignments of these two-latter fish suggest that they may be adult offspring from wild matings between stocked Ontario and New York fish. Of the ten adults that assigned to a specific stocked life-stage, nine had been stocked as spring fingerlings, and one was stocked as a fall fingerling. Of the 21 adults captured between 2013 and 2015, a minimum of 5 captured adults (26.3 %) were wild fish.