title: Ecosystemic effects of salmon farming increase mercury contamination in wild fish.
abstract: Net-pen salmon aquaculture has well-known effects on coastal ecosystems: farm waste increases sediment organic content and the incidence of sediment anoxia, supports increased production of deposit-feeding invertebrates, and attracts higher densities of demersal fish and other mobile carnivores. These impacts are widely considered to be localized and transitory, and are commonly managed by imposing a period of fallowing between cycles of production. The implications of these ecosystemic effects for contaminant cycling, however, have not previously been considered. We found elevated levels of mercury in demersal rockfishes near salmon farms in coastal British Columbia, Canada, attributable to a combination of higher rockfish trophic position and higher mercury levels in prey near farms. Mercury concentrations in long-lived species such as rockfishes change over a longer time scale than cycles of production and fallowing, and thus at least some important effects of fish farms may not be considered transitory.
authors.affiliation: Department of Biology, University of Victoria, Victoria, British Columbia. adebruyn@sfu.ca
authors.forename: Adrian M H
authors.initials: AM
authors.lastname: Debruyn
authors.forename: Marc
authors.initials: M
authors.lastname: Trudel
authors.forename: Nicola
authors.initials: N
authors.lastname: Eyding
authors.forename: Joel
authors.initials: J
authors.lastname: Harding
authors.forename: Heather
authors.initials: H
authors.lastname: McNally
authors.forename: Robert
authors.initials: R
authors.lastname: Mountain
authors.forename: Craig
authors.initials: C
authors.lastname: Orr
authors.forename: Diane
authors.initials: D
authors.lastname: Urban
authors.forename: Sergei
authors.initials: S
authors.lastname: Verenitch
authors.forename: Asit
authors.initials: A
authors.lastname: Mazumder
mesh_terms: D000818:Animals; D017756:Aquaculture / Q000379:methods / Q000592:standards; D017753:Ecosystem; D004784:Environmental Monitoring / Q000379:methods; D005398:Fisheries / Q000379:methods / Q000592:standards; D005399:Fishes / Q000254:growth & development* / Q000378:metabolism; D008628:Mercury / Q000032:analysis*; D012474:Salmon / Q000254:growth & development*; D014874:Water Pollutants, Chemical / Q000032:analysis
chemical_list: D014874:Water Pollutants, Chemical; D008628:Mercury