title: Biogeochemical malfunctioning in sediments beneath a deep-water fish farm.
abstract: We investigated the environmental impact of a deep water fish farm (190 m). Despite deep water and low water currents, sediments underneath the farm were heavily enriched with organic matter, resulting in stimulated biogeochemical cycling. During the first 7 months of the production cycle benthic fluxes were stimulated >29 times for CO(2) and O(2) and >2000 times for NH(4)(+), when compared to the reference site. During the final 11 months, however, benthic fluxes decreased despite increasing sedimentation. Investigations of microbial mineralization revealed that the sediment metabolic capacity was exceeded, which resulted in inhibited microbial mineralization due to negative feed-backs from accumulation of various solutes in pore water. Conclusions are that (1) deep water sediments at 8 °C can metabolize fish farm waste corresponding to 407 and 29 mmol m(-2) d(-1) POC and TN, respectively, and (2) siting fish farms at deep water sites is not a universal solution for reducing benthic impacts.
authors: Institute of Biology, University of Southern Denmark, Odense M, Denmark. valdemarsen@gmail.com
authors: Thomas
authors: T
authors: Valdemarsen
authors: Raymond J
authors: RJ
authors: Bannister
authors: Pia K
authors: PK
authors: Hansen
authors: Marianne
authors: M
authors: Holmer
authors: Arne
authors: A
authors: Ervik
mesh_terms: D000818:Animals; D017756:Aquaculture; D002245:Carbon Dioxide / Q000032:analysis; D055669:Ecological and Environmental Phenomena; D004784:Environmental Monitoring; D005399:Fishes; D019015:Geologic Sediments / Q000737:chemistry*; D008697:Methane / Q000032:analysis; D012474:Salmon / Q000254:growth & development; D012623:Seawater / Q000737:chemistry; D014873:Water Pollutants / Q000032:analysis*
chemical_list: D014873:Water Pollutants; D002245:Carbon Dioxide; D008697:Methane