Juvenile Pacific salmon (Oncorhynchus spp.), ecologically-related species, and associated biophysical data were collected from the marine waters of the northern region of southeastern Alaska in 2008. This annual survey marks 12 consecutive years of systematically monitoring how juvenile salmon interact in marine ecosystems, and was implemented to identify the relationships among biophysical parameters that influence habitat use, marine growth, predation, stock interactions, and year-class strength of juvenile salmon. This report summarizes findings from the 2008 survey year, and contrasts these findings to selected biophysical parameters of the prior 11 sampling years. Up to 13 stations were sampled in epipelagic waters over four time periods (20 sampling days) from May to August. Typically, at each station, fish, zooplankton, surface water samples, and physical profile data were collected during daylight using a surface rope trawl, conical and bongo nets, water sampler, and a conductivity-temperature-depth profiler. Surface (3-m) temperatures and salinities ranged from 6.8 to 11.6 ºC and 18.2 to 32.0 PSU from May to August. A total of 5,186 fish, representing 16 taxa, were captured in 56 rope trawl hauls from June to August. Juvenile salmon comprised about 97% of the total fish catch. Juvenile salmon occurred frequently in the trawl hauls, with pink (O. gorbuscha), chum (O. keta), sockeye (O. nerka), and coho salmon (O. kisutch) present in 6686% of the trawls, whereas juvenile Chinook salmon (O. tshawytscha) occurred less commonly, in about 39% of the hauls. Exceptionally few juvenile salmon were captured in June. Peak monthly catch rates of juvenile salmon differed by species: pink, chum, and coho were highest in July, whereas sockeye and Chinook were highest in August. Coded-wire tags were recovered from 11 juvenile coho salmon and three Chinook salmon (one juvenile and two immature). All fish were from hatchery and wild stocks originating in southeastern Alaska. Alaska enhanced stocks were also identified by thermal otolith marks from 39% of the chum and 4% of the sockeye salmon examined. Onboard stomach analysis of 20 potential predators, representing four species, did not provide evidence of predation on juvenile salmon. Biophysical measures from 2008 differed from prior years, in many respects. Integrated (20-m) temperatures and salinities were anomalously low and zooplankton densities were anomalously high in 2008. In addition, for most juvenile salmon species, unusual CPUE patterns, small fish size, and low condition residuals suggested that migration timing shifted to later than average. Long-term monitoring of key stocks of juvenile salmon, on seasonal and interannual time scales, will enable researchers to understand how growth, abundance, and ecological interactions affect year-class strength of salmon and to better understand their roles in North Pacific marine ecosystems.