title: Potential for Local Fertilization: A Benthocosm Test of Long-Term and Short-Term Effects of Mussel Excretion on the Plankton.
abstract: Mussel aquaculture has expanded worldwide and it is important to assess its impact on the water column and the planktonic food web to determine the sustainability of farming practices. Mussel farming may affect the planktonic food web indirectly by excreting bioavailable nutrients in the water column (a short-term effect) or by increasing nutrient effluxes from biodeposit-enriched sediments (a long-term effect). We tested both of these indirect effects in a lagoon by using plankton-enclosing benthocosms that were placed on the bottom of a shallow lagoon either inside of a mussel farm or at reference sites with no history of aquaculture. At each site, half of the benthocosms were enriched with seawater that had held mussels (excretion treatment), the other half received non-enriched seawater as a control treatment. We monitored nutrients ([PO43-] and [NH4+]), dissolved oxygen and plankton components (bacteria, the phytoplankton and the zooplankton) over 5 days. We found a significant relationship between long-term accumulation of mussel biodeposits in sediments, water-column nutrient concentrations and plankton growth. Effects of mussel excretion were not detected, too weak to be significant given the spatial and temporal variability observed in the lagoon. Effects of mussels on the water column are thus likely to be coupled to benthic processes in such semi-enclosed water bodies.
authors.affiliation: Umeå universitet, Institution för Ekologi, Miljö och Geovetenskap, Linnaeus väg 6 SE-901 87 Umeå, Sweden.
authors.forename: Mehdi
authors.identifier: http://orcid.org/0000-0003-0107-9374
authors.initials: M
authors.lastname: Cherif
authors.affiliation: McGill University, Department of Biology, 1205 ave Docteur-Penfield, H3A1B1 Montréal, Québec, Canada.
authors.forename: Monica
authors.initials: M
authors.lastname: Granados
authors.affiliation: McGill University, Department of Biology, 1205 ave Docteur-Penfield, H3A1B1 Montréal, Québec, Canada.
authors.forename: Sean
authors.initials: S
authors.lastname: Duffy
authors.affiliation: Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310 allée des Ursulines, G5L3A1, Rimouski, Québec, Canada.
authors.forename: Pauline
authors.initials: P
authors.lastname: Robert
authors.affiliation: Université Laval, Département de Biologie, 1045 av. De la médecine, G1V0A6 Québec, Québec, Canada.
authors.forename: Bérangère
authors.initials: B
authors.lastname: Péquin
authors.affiliation: Université Laval, Département de Biologie, 1045 av. De la médecine, G1V0A6 Québec, Québec, Canada.
authors.forename: Vani
authors.initials: V
authors.lastname: Mohit
authors.affiliation: Maurice Lamontagne Institute, Fisheries and Oceans Canada, G5H3Z4 Mont-Joli, Québec, Canada.
authors.forename: Christopher W
authors.initials: CW
authors.lastname: McKindsey
authors.affiliation: Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310 allée des Ursulines, G5L3A1, Rimouski, Québec, Canada.
authors.forename: Philippe
authors.initials: P
authors.lastname: Archambault
authors.affiliation: Merinov, 107-125 chemin du Parc, G4T1B3 Cap-aux-Meules, Québec, Canada.
authors.forename: Bruno
authors.initials: B
authors.lastname: Myrand
authors.affiliation: Université Laval, Département de Biologie, 1045 av. De la médecine, G1V0A6 Québec, Québec, Canada.
authors.forename: Connie
authors.initials: C
authors.lastname: Lovejoy
authors.affiliation: Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, 310 allée des Ursulines, G5L3A1, Rimouski, Québec, Canada.
authors.forename: Réjean
authors.initials: R
authors.lastname: Tremblay
authors.affiliation: Maurice Lamontagne Institute, Fisheries and Oceans Canada, G5H3Z4 Mont-Joli, Québec, Canada.
authors.forename: Stéphane
authors.initials: S
authors.lastname: Plourde
authors.affiliation: McGill University, Department of Biology, 1205 ave Docteur-Penfield, H3A1B1 Montréal, Québec, Canada.
authors.forename: Gregor F
authors.initials: GF
authors.lastname: Fussmann
mesh_terms: D000818:Animals; D017756:Aquaculture; D049872:Bivalvia / Q000502:physiology*; D020387:Food Chain; D010933:Plankton / Q000502:physiology*