title: Surface trawl survey for U.S. origin Atlantic salmon Salmo salar.
abstract: A surface trawl survey (2001-2005) in Penobscot Bay, Maine, U.S.A., and the nearshore Gulf of Maine waters was conducted to investigate early marine dynamics of a hatchery-dependent Atlantic salmon Salmo salar population from a severely modified river system. Data generated were used to evaluate the effect of stocking location and time on migration success and to describe the migratory pathways and environments that post-smolts traverse. Significant differences in early migration success were detected among different stocking groups, but subsequent marine survival was independent of stocking group. While the post-smolt population was primarily composed of hatchery origin smolt-stocked fish, other life-stage stocking strategies (i.e. parr stocking) represented a higher proportion of the population than previously assumed. Catch distribution suggests evidence of an initial marine migratory pathway out of the dynamic Penobscot Bay environment. The hypothesized benefits of a predator refuge based on the co-occurring species complex is considered minimal for emigrating post-smolts given a mismatch in the size overlap among species and low abundance of other co-occurring diadromous populations. These data can be used to modify current management actions to optimize S. salar recovery and inform future research agendas.
authors.affiliation: National Marine Fisheries Service, Northeast Fisheries Science Center, Atlantic Salmon Research and Conservation Task, 166 Water Street, Woods Hole, MA 02543, USA. Tim.Sheehan@noaa.gov
authors.forename: T F
authors.initials: TF
authors.lastname: Sheehan
authors.forename: M D
authors.initials: MD
authors.lastname: Renkawitz
authors.forename: R W
authors.initials: RW
authors.lastname: Brown
mesh_terms: D025041:Animal Migration; D000818:Animals; D001267:Atlantic Ocean; D017753:Ecosystem; D005398:Fisheries; D008281:Maine; D011157:Population Dynamics; D045483:Rivers; D020317:Salmo salar