FN Archimer Export Format PT J TI Role of tidal pumping on nutrient cycling in a temperate lagoon (Arcachon Bay, France) BT AF DEBORDE, J ANSCHUTZ, P AUBY, Isabelle GLE, C COMMARIEU, M MAURER, Daniele LECROART, P ABRIL, G AS 1:1;2:1;3:2;4:1;5:1;6:2;7:1;8:1; FF 1:;2:;3:PDG-DOP-LER-LERAR;4:;5:;6:PDG-DOP-LER-LERAR;7:;8:; C1 Univ Bordeaux 1, CNRS, UMR 5805, EPOC, F-33405 Talence, France. IFREMER, DEL AR, F-33120 Arcachon, France. C2 UNIV BORDEAUX, FRANCE IFREMER, FRANCE SI ARCACHON SE PDG-DOP-LER-LERAR IN WOS Ifremer jusqu'en 2018 copubli-france copubli-univ-france IF 2.977 TC 60 UR https://archimer.ifremer.fr/doc/2008/publication-3927.pdf LA English DT Article DE ;Arcachon Bay;Pore waters seeping;Nitrogen;Phosphorus;Organic matter mineralization;Tidal creek water;Tidal pump AB The hypothesis of nutrient-rich pore-waters seeping at low tide through sediments to channel waters, which drain tidal flats during ebb, was evaluated in the Arcachon lagoon. The back of the bay is affected by freshwater inputs and underground freshwater discharges. The upper part of tidal flat consists of permeable sandy sediments, which are covered by a muddy sediment layer on the lower part. Permeable sediments outcrop in the bed of channel web. Surface water chemistry and early diagenesis processes in sediment were estimated by collecting channel web waters and cores on a tidal flat and in channels at different seasons and time scales. Waters from tidal creeks are under-oxygenated, and enriched in reduced solutes. Muddy sediments showed evidences of strong organic matter mineralization and bioturbation. Underlying permeable sandy sediments revealed as well evidences of an enrichment of inorganic nutrients, and dilution with fresh continental groundwater. During ebb, tidal creek waters stem from mudflats by seeping of anoxic pore-waters, and from permeable sediments by advection of reduced waters. A rough estimation shows that the yearly contribution of this tidal pump of pore-waters for dissolved inorganic phosphorus (DIP) and ammonia inputs is of the same order of magnitude than river inputs for the studied part of the bay. Extrapolated to the whole Arcachon lagoon, pore-water discharge at low tide supplies to water column at least 556 kmol yr(-1) and 18300 kmol yr(-1) of DIP and NH4+, respectively. Tidal drainage at low tide represents therefore a minimal contribution of recycled nutrient of 55% for DIP and 15% for dissolved inorganic nitrogen to the lagoon. (c) 2008 Elsevier B.V. All rights reserved. PY 2008 PD FEB SO Marine Chemistry SN 0304-4203 PU Elsevier VL 109 IS 1-2 UT 000254769500008 BP 98 EP 114 DI 10.1016/j.marchem.2007.12.007 ID 3927 ER EF