Regional Projections of Climate Change Effects on Thermal Habitat Space for Fishes in Stratified Ontario Lakes
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Ministry of Natural Resources and Forestry Science and Regional Projections of Research Climate Change Effects on Thermal Habitat Space for 41 Fishes in Stratified Ontario CLIMATE Lakes CHANGE RESEARCH REPORT CCRR-41 Responding to Climate Change Through Partnership Sustainability in a Changing Climate: An Overview of MNR’s Climate Change Strategy (2011-2014) Climate change will affect all MNR programs and • Facilitate the development of renewable energy the natural resources for which it has responsibility. by collaborating with other Ministries to promote This strategy confirms MNR’s commitment to the the value of Ontario’s resources as potential green Ontario government’s climate change initiatives such energy sources, making Crown land available as the Go Green Action Plan on Climate Change for renewable energy development, and working and outlines research and management program with proponents to ensure that renewable energy priorities for the 2011-2014 period. developments are consistent with approval requirements and that other Ministry priorities are Theme 1: Understand Climate Change considered. MNR will gather, manage, and share information • Provide leadership and support to resource users and knowledge about how ecosystem composition, and industries to reduce carbon emissions and structure and function – and the people who live and increase carbon storage by undertaking afforestation, work in them – will be affected by a changing climate. protecting natural heritage areas, exploring Strategies: opportunities for forest carbon management • Communicate internally and externally to build to increase carbon uptake, and promoting the awareness of the known and potential impacts increased use of wood products over energy- of climate change and mitigation and adaptation intensive, non-renewable alternatives. options available to Ontarians. • Help resource users and partners participate in a • Monitor and assess ecosystem and resource carbon offset market, by working with our partners conditions to manage for climate change in to ensure that a robust trading system is in place collaboration with other agencies and organizations. based on rules established in Ontario (and potentially • Undertake and support research designed in other jurisdictions), continuing to examine the to improve understanding of climate change, mitigation potential of forest carbon management including improved temperature and precipitation in Ontario, and participating in the development of projections, ecosystem vulnerability assessments, protocols and policies for forest and land-based and improved models of the carbon budget and carbon offset credits. ecosystem processes in the managed forest, the settled landscapes of southern Ontario, and the Theme 3: Help Ontarians Adapt forests and wetlands of the Far North. MNR will provide advice and tools and techniques to • Transfer science and understanding to decision- help Ontarians adapt to climate change. Strategies makers to enhance comprehensive planning and include: management in a rapidly changing climate. • Maintain and enhance emergency management capability to protect life and property during extreme Theme 2: Mitigate Climate Change events such as flooding, drought, blowdown and MNR will reduce greenhouse gas emissions in wildfire. support of Ontario’s greenhouse gas emission • Use scenarios and vulnerability analyses to develop reduction goals. Strategies: and employ adaptive solutions to known and • Continue to reduce emissions from MNR operations emerging issues. though vehicle fleet renewal, converting to other • Encourage and support industries, resource users high fuel efficiency/low-emissions equipment, and communities to adapt, by helping to develop demonstrating leadership in energy-efficient facility understanding and capabilities of partners to adapt development, promoting green building materials their practices and resource use in a changing and fostering a green organizational culture. climate. • Evaluate and adjust policies and legislation to respond to climate change challenges. Regional Projections of Climate Change Effects on Thermal Habitat Space for Fishes in Stratified Ontario Lakes Charles K. Minns1,2, Brian J. Shuter2,3, and Simon Fung3 1 Great Lakes Laboratory for Fisheries and Aquatic Sciences, Fisheries and Oceans Canada Bayfield Institute, 867 Lakeshore Road, P.O. Box 5050, Burlington, ON L7R 4A6 2 Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street Toronto, ON M5S 3B2 3 Harkness Lab Fisheries Research, Aquatic Research and Monitoring Section, Science and Research Branch, Ontario Ministry of Natural Resources and Forestry, Peterborough, ON K9J 8M5 2014 Science and Research Branch • Ontario Ministry of Natural Resources and Forestry © 2014, Queen’s Printer for Ontario Printed in Ontario, Canada To request copies of this publication: [email protected] Cette publication hautement spécialisée, Regional Projections of Climate Change Effects on Ice Cover and Open-Water Duration for Ontario Lakes Using Updated Ice-Date Models n’est disponible qu’en anglais en vertu du Règlement 671/92 qui en exempte l’application de la Loi sur les services en français. Pour obtenir de l’aide en français, veuillez communiquer avec le Ministère des Richesses naturelles et des Forêts au [email protected]. This paper contains recycled materials. i Summary To better understand the effects of projected changes in climate on suitable habitat space for fish in Ontario’s inland lakes, models for ice break-up and freeze-up dates and for seasonal open water temperature profiles were joined to project future thermal regimes in a representative stratified lake for each of Ontario’s secondary watersheds under future climates using four global climate models (GCMs) under alternate greenhouse gas emissions scenarios. The seasonal availability of preferred temperature habitat in those representative lakes was projected for fishes in three thermal guilds (cold, cool, and warm). The observed 1971 to 2000 climate averages (referred to as norms) were applied as a baseline to assess changes in suitable habitat availability. Both volume and area habitat availability measures were computed. Four measures of seasonal habitat availability by fish type were assessed: (a) the proportion of the year when suitable habitat was available, (b) the proportion of total lake space (volume or area) supporting suitable habitat, averaged over those parts of the year when some suitable space was present, (c) the proportion of suitable lake space available over a year—the product of (a) and (b), and (d) the proportion of suitable lake space available on the midsummer day when lake surface temperature reached its peak. The results showed different regional response patterns among the three fish types. Coldwater fish such as lake trout will face longer periods in summer confined to ever smaller suitable thermal spaces. Coolwater fish such as walleye will gain more seasonal habitat space in the north of the province while becoming more constricted in southern areas. Warmwater fish such as smallmouth bass will be able to expand northwards regionally and enjoy more suitable space, although if climate warming reaches the upper bounds projected by some GCMs even they will eventually become constricted. Further development of this thermal habitat model is warranted to account for more factors affecting lakes and their fishes and to allow projections for more than one type of lake. Résumé Prévisions régionales des effets du changement climatique sur l’habitat thermique du poisson dans les lacs stratifiés de l’Ontario Afin de mieux comprendre les effets que le changement climatique aurait sur l’habitat du poisson des lacs intérieurs de l’Ontario, des modèles ont été établis pour les dates de la formation et de la rupture des glaces et pour les courbes de température saisonnières des eaux libres. Ces modèles ont ensuite été réunis dans le but de prédire les régimes thermiques futurs dans un lac stratifié représentatif des lacs de chacun des bassins versants secondaires de l’Ontario exposés à des climats futurs, prédits au moyen de quatre modèles du climat mondial établis d’après divers scénarios d’émissions de gaz à effet de serre. La présence saisonnière d’un habitat d’une température idéale dans les lacs représentatifs a été prédite pour le poisson dans trois strates thermiques (froide, fraîche et assez chaude). Les moyennes climatiques observées entre 1971 et 2000 (ce qu’on appelle les normes) ont servi de points de référence pour déterminer les changements relatifs à la présence d’un habitat convenable. Le volume et la superficie de l’habitat ont été calculés. Quatre mesures pour la présence d’un habitat saisonnier convenable, établies selon le type de poissons ont été examinées. Ce sont les mesures suivantes : a) le pourcentage de l’année quand il existe un habitat convenable; b) le pourcentage de l’espace total du lac (volume ou superficie) pouvant soutenir un habitat convenable, réparti en moyenne sur les mois de l’année quand un habitat convenable est présent; c) le pourcentage de l’espace du lac qui soutient un habitat convenable au cours d’une année, soit le produit de a), b) et d) indiquant le pourcentage de l’espace du lac soutenant un habitat convenable au milieu de l’été, quand la température à la surface atteint son zénith. Les résultats indiquent différentes tendances régionales relativement aux réactions chez les trois types de poissons. Le poisson d’eau froide