FN Archimer Export Format PT J TI A spatially explicit ecosystem model of seston depletion in dense mussel culture BT AF GRANT, J BACHER, Cedric CRANFORD, P GUYONDET, T CARREAU, M AS 1:1;2:2;3:3;4:4;5:5; FF 1:;2:PDG-DOP-DCB-DYNECO-BENTHOS;3:;4:;5:; C1 Dalhousie Univ, Dept Oceanog, Halifax, NS B3H 4J1, Canada. Inst Francais Rech Exploitat Mer, F-29280 Plouzane, France. Bedford Inst Oceanog, Ecosyst Res Div, Dept Fisheries & Oceans, Dartmouth, NS B2Y 4A2, Canada. UQAR, ISMER, Rimouski, PQ G5L 3A1, Canada. Hatch Ltd, Synexus Global BU, Montreal, PQ H3B 2G2, Canada. C2 UNIV DALHOUSIE, CANADA IFREMER, FRANCE BEDFORD INST OCEANOG, CANADA UNIV QUEBEC (UQAR), CANADA HATCH LTD, CANADA SI BREST SE PDG-DOP-DCB-DYNECO-BENTHOS IN WOS Ifremer jusqu'en 2018 copubli-int-hors-europe IF 2.255 TC 61 UR https://archimer.ifremer.fr/doc/2008/publication-6951.pdf LA English DT Article DE ;Towed sensors;Nutrient dynamics;Circulation model;Phytoplankton;Carrying capacity;Shellfish aquaculture;Estuaries;Ecosystem model AB A fully-coupled biological-physical-chemical model of a coastal ecosystem was constructed to examine the impact of suspended mussel culture on phytoplankton biomass in Tracadie Bay, Prince Edward Island, Canada. Due to the extent of mussel culture there, we hypothesised that shellfish filtration would control the concentration and distribution of phytoplankton and other suspended particles in the bay. Circulation was delineated with a tidally-driven 2D numerical model and used to drive an ecosystem model with a focus on pelagic components including phytoplankton production, nutrients, detritus, and mussels. The benthos were treated as a sink. Nutrients and seston were forced by tidal exchange and river input, with phytoplankton additionally forced by light. Boundary conditions of seston and nutrients were derived from field studies with an emphasis on the contrast between spring (high river nutrients, low temperature) and summer (low river inputs and high temperatures). Model output was used to map phytoplankton carbon over the bay for each season and in the presence of mussels and river nutrient input. Results indicate severe depletion effects of mussel culture on overall phytoplankton biomass, but no spatial pattern that can be attributed to grazing alone. Primary production generated by nutrient-rich river water created a mid-bay spike in phytoplankton that dominated the spatial pattern of chlorophyll-based carbon. Model results were validated with surveys from a towed sensor array (Acrobat) that confirmed the river influence and indicated bay-wide depletion of 29% between high and low water. Our model results indicate that the farm-scale depletion emphasised in previous studies cannot simply be extrapolated to seston limitation at the ecosystem level. (C) 2007 Elsevier B.V. All rights reserved. PY 2008 PD SEP SO Journal of Marine Systems SN 0924-7963 PU Elsevier VL 73 IS 1-2 UT 000259130000012 BP 155 EP 168 DI 10.1016/j.jmarsys.2007.10.007 ID 6951 ER EF