11 All correspondence should be addressed to e-mail: North Paciic Anadromous Fish Commission Technical Report No. 9: 11-20, 2013 Recent Advances in Marine Juvenile Paciic Salmon Research in North America Marc Trudel 1,2 and Eric Hertz 2 1 Fisheries and Oceans Canada, Paciic Biological Station, 3190 Hammond Bay Road, Nanaimo, BC V9T 6N7, Canada 2 Department of Biology, University of Victoria, 3800 Finnerty Rd., Victoria, BC V8P 5C2, Canada Keywords: juvenile Paciic salmon, growth, survival, climate effects, distribution, migration, disease Paciic salmon sustain heavy and highly variable losses in the ocean, with natural mortality rates generally exceeding 90-95% during their marine life (Bradford 1995). Most of this mortality is thought to occur during two critical periods: an early predation-based mortality that occurs within the irst few weeks to months following ocean entry, and a starvation-based mortality that occurs following their irst winter at sea (Pearcy 1992; Beamish and Manhken 2001). Hence, studies that investigate the processes affecting the survival of Paciic salmon during the juvenile phase of their marine life are critically needed to understand the recruitment variability of Paciic salmon. Here, we provide a brief overview of the progress that has been made in North America on the marine ecology of juvenile Paciic salmon since the “Second NPAFC International Workshop on Factors Affecting Production of Juvenile Salmon” held in Sapporo, Japan, in 2006. We focused our effort on primary publications in peer-reviewed journals as well as NPAFC publications (i.e., Documents, Technical Reports, and Bulletins) and present selected key indings due to the large number of publications that had to be covered as part of this overview (Fig. 1). Fig. 1. Number of NPAFC publications (red bars) and peer-reviewed journal articles (grey bars) published between 2006 and 2012 in North America pertaining to marine ecology of juvenile Paciic salmon. The dotted red line represents the trend in the number of publications that are produced each year, excluding seven papers that appeared in a special issue of the American Fisheries Society Symposium Series focusing on juvenile salmon in 2007. Marc.Trudel@dfo-mpo.gc.ca M. Trudel. We compiled 225 studies that investigated different aspects of the marine ecology of juvenile Paciic salmon in North America, including survival rates and mechanisms, ocean and climate effects, distribution and migration, bioenergetics and physiology, diet and trophic interactions (Table 1; Fig. 1). Overall, the number of publications has increased steadily by approximately ive papers each year since 2006 (Fig. 1). On average, 25% of the papers that have been published during that time period were contributed through NPAFC (Fig. 1). The majority of these studies focused on one (60%) or two (21%) salmon species at a time. Chinook salmon and pink salmon were the two most frequently studied species (Fig. 2).