Status of the Arctic Grayling (Thymallus arcticus) in Alberta: Update 2015 Alberta Wildlife Status Report No. 57 (Update 2015) Status of the Arctic Grayling (Thymallus arcticus) in Alberta: Update 2015 Prepared for: Alberta Environment and Parks (AEP) Alberta Conservation Association (ACA) Update prepared by: Christopher L. Cahill Much of the original work contained in the report was prepared by Jordan Walker in 2005. This report has been reviewed, revised, and edited prior to publication. It is an AEP/ACA working document that will be revised and updated periodically. Alberta Wildlife Status Report No. 57 (Update 2015) December 2015 Published By: i i ISBN No. 978-1-4601-3452-8 (On-line Edition) ISSN: 1499-4682 (On-line Edition) Series Editors: Sue Peters and Robin Gutsell Cover illustration: Brian Huffman For copies of this report, visit our web site at: http://aep.alberta.ca/fish-wildlife/species-at-risk/ (click on “Species at Risk Publications & Web Resources”), or http://www.ab-conservation.com/programs/wildlife/projects/alberta-wildlife-status-reports/ (click on “View Alberta Wildlife Status Reports List”) OR Contact: Alberta Government Library 11th Floor, Capital Boulevard Building 10044-108 Street Edmonton AB T5J 5E6 http://www.servicealberta.gov.ab.ca/Library.cfm [email protected] 780-427-2985 This publication may be cited as: Alberta Environment and Parks and Alberta Conservation Association. 2015. Status of the Arctic Grayling (Thymallus arcticus) in Alberta: Update 2015. Alberta Environment and Parks. Alberta Wildlife Status Report No. 57 (Update 2015). Edmonton, AB. 96 pp. ii PREFACE Every five years, Alberta Environment and Parks reviews the general status of wildlife species in Alberta. General status assessments have been conducted in 1991 (The Status of Alberta Wildlife), 1996 (The Status of Alberta Wildlife), 2000, 2005, 2010, and 2015 (available in a searchable database at http://aep.alberta.ca/fish-wildlife/species-at-risk/ since 2000). The general status process assigns individual species “ranks” that reflect the perceived level of risk to populations that occur in the province. Such designations are determined from extensive consultations with professional and amateur biologists, and from a variety of readily available sources of population data. The 2015 general status assessments for vertebrates used the same methodology as assessments from 2000 to 2010, and adopted methodology from NatureServe (http://www.natureserve.org/) for invertebrates and plants. A key objective of general status assessment is to identify species that may be considered for more detailed status determinations. The Alberta Wildlife Status Report Series is an extension of the general status exercise, and provides comprehensive current summaries of the biological status of selected wildlife species in Alberta. Priority is given to species that are considered at some level to be at risk or potentially at risk (e.g., general status of At Risk or May Be At Risk, NatureServe rank of S1, Committee on the Status of Endangered Wildlife in Canada [COSEWIC] rank of Endangered/Threatened at a national level), and species that are of uncertain status (e.g., general status of Undetermined). Reports in this series are published and distributed by Alberta Conservation Association and Alberta Environment and Parks. They are intended to provide up-to-date information that will be useful to resource professionals for managing populations of species and their habitats in the province. The reports are also designed to provide detailed information that will assist Alberta’s Endangered Species Conservation Committee in identifying species that may be formally designated as Endangered or Threatened under Alberta’s Wildlife Act. To achieve these goals, the reports have been authored and/or reviewed by individuals with unique local expertise in the biology and management of each species. ii iii EXECUTIVE SUMMARY The Arctic grayling (Thymallus arcticus) in Alberta is currently considered a Species of Special Concern, and is considered a high-priority candidate for assessment by the Committee on the Status of Endangered Wildlife in Canada. This report compiles recent and historical information on Arctic grayling in Alberta, assessing its current population status and identifying information gaps for future research. The Arctic grayling is a cold-water species. In Alberta, grayling are primarily found in boreal and foothills streams in the Athabasca, Peace and Hay river drainages. These systems represent the southern extent of the species’ North American range, with the exception of a few disjunct remnant populations in the upper Missouri River watershed in Montana. Arctic grayling monitoring in Alberta has only recently been standardized. The Alberta Arctic grayling Fish Sustainability Index (FSI) summarizes the species’ abundance and status in all watersheds containing grayling. This summary provided a significant part of the information used to evaluate grayling in this report. The FSI uses data from fisheries sampling projects, primarily electrofishing and angling, as well as qualitative information (e.g., interviews with anglers, retired biologists, and retired Fish and Wildlife officers, archived data sets, historical reports). The FSI assessed grayling status in two time periods: historical (pre-1960) and recent (2004–2014). Using this information, biologists speculate that grayling abundance has declined by roughly 70% since 1960; however, numbers of grayling in Alberta are reasonably described as remaining in the hundreds of thousands of adult fish. With a grayling generation time of seven years, this decline occurred over eight generations. Overharvest by anglers probably played an important role in this speculated historical decline, as grayling were a popular sport fish and are easily captured by anglers. Human activities that degrade stream habitats, such as habitat fragmentation caused by improperly installed culverts, pose another important threat to Arctic grayling persistence in Alberta. Additionally, climate modelling suggests anthropogenic climate change will greatly reduce the amount of thermally suitable habitat available to grayling in Alberta during this century. The standardized sampling program will help inform grayling management in Alberta, and a climate adaptation strategy that focuses on maintaining or enhancing ecological resilience may mitigate threats related to climate change. iv ACKNOWLEDGEMENTS For preparation of the original 2005 manuscript by Jordan Walker*: I would like to acknowledge the many people who have contributed to the preparation of this report. Special thanks must go to David Park (Alberta Conservation Association), Travis Ripley (Alberta Sustainable Resource Development), Dr. Michael Sullivan (Alberta Sustainable Resource Development) and Michael Bryski (Alberta Environment) for their generous contributions of data and time for discussions. I extend my thanks to David Park (Alberta Conservation Association), Jim O’Neil (RL&L Environmental Services Ltd./Golder Associates), Nyree Sharp (Alberta Conservation Association), Robin Gutsell (Alberta Sustainable Resource Development), Chris Davis (Alberta Sustainable Resource Development), Travis Ripley (Alberta Sustainable Resource Development), and Carl Hunt (Alberta Sustainable Resource Development – retired) who reviewed this report and provided many constructive comments so it could be improved. I would like to thank Michael Blackburn (Alberta Conservation Association), Kevin Gardiner (Alberta Conservation Association), and Craig Johnson (Alberta Conservation Association) for their assistance in locating and providing necessary survey data. A special thanks to Jim Stelfox (Alberta Sustainable Resource Development) and Terry Clayton (Alberta Sustainable Resource Development) for sharing their expertise on grayling stocking and abundance in the southern part of the province. Ward Hughson (Aquatics Specialist, Jasper National Park) provided valuable insight into the distribution and stocking history of grayling in Jasper National Park. * Note that some of the affiliations for people acknowledged in this section may be outdated. For preparation of the updated manuscript in 2015 by Christopher L. Cahill: I thank my M.Sc. supervisor Dr. William Tonn (University of Alberta; U of A) and Ph.D. supervisor Dr. John Post (University of Calgary; U of C) for providing me the opportunity to update this manuscript while also attending graduate school. Dr. Michael Sullivan (Alberta Environment and Parks; AEP) provided guidance regarding climate modeling, the Alberta Fish Sustainability Index, and provided many helpful comments on several drafts of this report. W. Hughson (Parks Canada), T. Clayton (AEP), J. Janes (Alberta Biodiversity Monitoring Institute), and J. Stelfox (Alberta Environment and Sustainable Resource Development – retired) contributed personal communications to C. Cahill and M. Sullivan. Important conversations and contributions from Laura MacPherson (AEP), Jessica Reilly (U of A/AEP), Fred Noddin (U of A), Craig Johnson (AEP), Bryan Maitland (U of A), Kyle Wilson (U of C), and Steph Mogensen (U of C) are also gratefully acknowledged. I extend thanks to Diana Stralberg (U of A), Dr. Erin Bayne (U of A), and Dr. Fangliang He (U of A) for important discussions regarding statistical modeling. Laura MacPherson and Chad Sherburne (AEP) provided much needed assistance with GIS and mapping. Dana Seidel (U of A) assisted with HawthsTools. Sue Peters (Alberta Conservation