Early microhabitat use by age 0 year brook charr Salvelinus fontinalis in lakes P. A. BIRO*†, C. BECKMANN‡ AND M. S. RIDGWAY§ †Department of Environmental Science, University of Technology, Sydney Box 123 Broadway, NSW 2007, Australia, ‡School of Biological Sciences, University of Sydney, Sydney NSW 2007, Australia and §Harkness Laboratory of Fisheries Research, Aquatic Research and Development Section, Ontario Ministry of Natural Resources, Trent University, 2140 East Bank Drive Peterborough, Ontario, K9J 7B8 Canada (Received 15 July 2007, Accepted 12 April 2008) The early habitat use of age 0 year brook charr Salvelinus fontinalis in three north temperate lakes which differ in terms of shoreline physical habitat is described. In the two lakes, which contained abundant shoreline woody debris and inundated vegetation, brook charr were observed in extremely close proximity with these habitat features, near shore and near the surface. Fish were absent from open areas away from shore unless in close proximity with fallen floating logs near the surface, extending offshore. In a third lake that had no woody debris or inundated shoreline vegetation, brook charr were observed exclusively in close proximity with the shoreline itself, and near the surface. In all three lakes, fish were most closely associated with the shoreline and with woody debris and inundated vegetation (when present) shortly after emergence, and significantly farther from shore and deeper in the water column thereafter. # 2008 The Authors Journal compilation # 2008 The Fisheries Society of the British Isles Key words: habitat; habitat selection; nearshore; riparian; woody debris. INTRODUCTION Movements of brook charr Salvelinus fontinalis (Mitchell) (often termed brook trout) in lakes and streams generally fall into one of two categories: individual fish may remain stationary and forage from a relatively fixed location, or in contrast, fish may move and actively forage for items near or at the surface (Grant & Noakes, 1987; Biro & Ridgway, 1995; McLaughlin, 2001). In streams, density-dependent processes associated with territorial behaviour can contribute to this movement dichotomy (Grant & Noakes, 1987) and in other cases the movement dichotomy is adaptive (McLaughlin, 2001). In lakes, dichotomous movements are not generated by a territorial process but instead reflect outward expansion and redistribution of a cohort away from their site *Author to whom correspondence should be addressed. Tel.: þ61 95148310; fax: þ61 95148332; email: peter.biro@uts.edu.au Journal of Fish Biology (2008) 73, 226–240 doi:10.1111/j.1095-8649.2008.01930.x, available online at http://www.blackwell-synergy.com 226 # 2008 The Authors Journal compilation # 2008 The Fisheries Society of the British Isles