title: Trophic structure of a coastal fish community determined with diet and stable isotope analyses.
abstract: A combination of dietary guild analysis and nitrogen (δ(15) N) and carbon (δ(13) C) stable-isotope analysis was used to assess the trophic structure of the fish community in Rhode Island and Block Island Sounds, an area off southern New England identified for offshore wind energy development. In the autumn of 2009, 2010 and 2011, stomach and tissue samples were taken from 20 fish and invertebrate species for analysis of diet composition and δ(15) N and δ(13) C signatures. The food chain in Rhode Island and Block Island Sounds comprises approximately four trophic levels within which the fish community is divided into distinct dietary guilds, including planktivores, benthivores, crustacivores and piscivores. Within these guilds, inter-species isotopic and dietary overlap is high, suggesting that resource partitioning or competitive interactions play a major role in structuring the fish community. Carbon isotopes indicate that most fishes are supported by pelagic phytoplankton, although there is evidence that benthic production also plays a role, particularly for obligate benthivores such as skates Leucoraja spp. This type of analysis is useful for developing an ecosystem-based approach to management, as it identifies species that act as direct links to basal resources as well as species groups that share trophic roles.
authors.affiliation: Graduate School of Oceanography, University of Rhode Island, 215 South Ferry Rd, Narragansett, RI, 02882, U.S.A.
authors.forename: A J
authors.initials: AJ
authors.lastname: Malek
authors.affiliation: Graduate School of Oceanography, University of Rhode Island, 215 South Ferry Rd, Narragansett, RI, 02882, U.S.A.
authors.forename: J S
authors.initials: JS
authors.lastname: Collie
authors.affiliation: Roger Williams University, Department of Marine Biology, 1 Old Ferry Rd, Bristol, RI, 02809, U.S.A.
authors.forename: D L
authors.initials: DL
authors.lastname: Taylor
mesh_terms: D000818:Animals; D001267:Atlantic Ocean; D002244:Carbon; D002247:Carbon Isotopes / Q000032:analysis; D004032:Diet; D017753:Ecosystem; D005247:Feeding Behavior; D005399:Fishes; D020387:Food Chain; D005766:Gastrointestinal Contents; D007448:Invertebrates; D009511:New England; D009584:Nitrogen; D009587:Nitrogen Isotopes / Q000032:analysis; D012860:Skates, Fish
chemical_list: D002247:Carbon Isotopes; D009587:Nitrogen Isotopes; D002244:Carbon; D009584:Nitrogen
keywords: fish diet; food webs; north-west Atlantic; trophic ecology; δ13C; δ15N