Changes in the condition, early growth, and trophic position of Lake Trout (Salvelinus namaycush) in response to an experimental aquaculture operation

• Main Authors: Kennedy, Patrick J., Blanchfield, Paul J., Kidd, Karen A, Paterson, Michael J., Podemski, Cheryl L., Rennie, Michael D.
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: NRC Research Press (a division of Canadian Science Publishing) 2018
• Subjects: Cottus cognatus; Slimy sculpin
• Online Access: http://hdl.handle.net/1807/95406; http://www.nrcresearchpress.com/doi/abs/10.1139/cjfas-2017-0578

We analyzed changes in the condition, early growth and resource use of Lake Trout from a Boreal Shied lake in response to an experimental aquaculture operation. Annual small-scale commercial production of Rainbow Trout (Oncorhynchus mykiss) resulted in increased Lake Trout body condition during aquaculture operations which was positively related to minnow CPUE. Incremental increases in growth led to larger Lake Trout following aquaculture. While the littoral energy assimilated by Lake Trout did not change linearly from 2002-2009, we observed a shift towards littoral energy use in the last year of aquaculture and for two years after the experiment, coincident with low densities of Mysis diluviana. Lake Trout trophic position declined from 2002-2009, suggesting increased foraging on secondary vs. tertiary consumers. Minnow and Slimy Sculpin (Cottus cognatus) CPUE increased by 5.2 and 5.5-fold, respectively, and Mysis diluviana densities decreased by 93%. Changes observed in the experimental lake were much greater than those observed in a nearby reference lake. Our results suggest that moderate nutrient enrichment from aquaculture may benefit Lake Trout in oligotrophic Boreal Shield lakes. The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author.