title: Quantifying alosine prey in the diets of marine piscivores in the Gulf of Maine.
abstract: The objectives of this work were to quantify the spatial and temporal distribution of the occurrence of anadromous fishes (alewife Alosa pseudoharengus, blueback herring Alosa aestivalis and American shad Alosa sapidissima) in the stomachs of demersal fishes in coastal waters of the north-west Atlantic Ocean. Results show that anadromous fishes were detectable and quantifiable in the diets of common marine piscivores for every season sampled. Even though anadromous fishes were not the most abundant prey, they accounted for c. 5-10% of the diet by mass for several marine piscivores. Statistical comparisons of these data with fish diet data from a broad-scale survey of the north-west Atlantic Ocean indicate that the frequency of this trophic interaction was significantly higher within spatially and temporally focused sampling areas of this study than in the broad-scale survey. Odds ratios of anadromous predation were as much as 460 times higher in the targeted sampling as compared with the broad-scale sampling. Analyses indicate that anadromous prey consumption was more concentrated in the near-coastal waters compared with consumption of a similar, but more widely distributed species, the Atlantic herring Clupea harengus. In the context of ecosystem-based fisheries management, the results suggest that even low-frequency feeding events may be locally important, and should be incorporated into ecosystem models.
authors.affiliation: Greater Atlantic Regional Office, National Marine Fisheries Service, 55 Great Republic Drive, Gloucester, MA 01930, U.S.A.
authors.forename: S P
authors.initials: SP
authors.lastname: McDermott
authors.affiliation: Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, P. O. Box 38, Solomons, MD 20688, U.S.A.
authors.forename: N C
authors.initials: NC
authors.lastname: Bransome
authors.affiliation: Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, MA 02543, U.S.A.
authors.forename: S E
authors.initials: SE
authors.lastname: Sutton
authors.affiliation: Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, MA 02543, U.S.A.
authors.forename: B E
authors.initials: BE
authors.lastname: Smith
authors.affiliation: Northeast Fisheries Science Center, National Marine Fisheries Service, National Oceanic and Atmospheric Administration, 166 Water Street, Woods Hole, MA 02543, U.S.A.
authors.forename: J S
authors.initials: JS
authors.lastname: Link
authors.affiliation: Chesapeake Biological Laboratory, University of Maryland Center for Environmental Science, P. O. Box 38, Solomons, MD 20688, U.S.A.
authors.forename: T J
authors.initials: TJ
authors.lastname: Miller
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D003247:Conservation of Natural Resources; D004032:Diet / Q000662:veterinary*; D005398:Fisheries; D005399:Fishes; D020387:Food Chain; D005766:Gastrointestinal Contents; D008281:Maine; D011235:Predatory Behavior; D012621:Seasons
keywords: Gulf of Maine; alewife; demersal fish; river herring; trophic interaction