Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)

A non-stationary state mass balance of the type advocated by the International Geosphere-Biosphere Programme/Land-Ocean Interactions in the Coastal Zone (IGBP/LOICZ) has been used to assess net ecosystem metabolism in the Pontevedra Ria (NW Spain), a large embayment subject to transient upwelling o...

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Main Authors: Andre W Dale, Ricardo Prego
Format: Article
Language:English
Published: Universidad Autónoma de Baja California 2005-03-01
Series:Ciencias Marinas
Subjects:
Online Access:https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/94
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author Andre W Dale
Ricardo Prego
author_facet Andre W Dale
Ricardo Prego
author_sort Andre W Dale
collection DOAJ
description A non-stationary state mass balance of the type advocated by the International Geosphere-Biosphere Programme/Land-Ocean Interactions in the Coastal Zone (IGBP/LOICZ) has been used to assess net ecosystem metabolism in the Pontevedra Ria (NW Spain), a large embayment subject to transient upwelling of Eastern North Atlantic Central Water (ENACW) under favourable meteorological conditions. Nitrate (NO3–) and phosphate (PO43–) data spanning 12 months were resolved at the oceanic boundary by treating the ria as a single box of constant volume. The nutrient budget was scaled up to an estimate of net community production (NCP) using the compositional relationship of local phytoplankton. The mean annual NCP predicted by the NO3– balance was 24.0 mgC m–2 h–1, and 35.8 mgC m–2 h–1 by the PO43– budget. Nutrient fluxes into the reservoir were strongly driven by the incoming oceanic flow throughout the year, which supplied 88% and 98% of the total NO3– and PO43– load, respectively. A high NCP (NO3–) of 57.2 mgC m–2 h–1 was calculated for the height of the growth season contemporaneous with ENACW intrusion, whereas a slightly higher value of 61.4 mgC m–2 h–1 corresponded to PO43–. Nutrient limitation was variable throughout the sampling, switching from PO43– to NO3– from winter to spring concurrent with a drop in riverine PO43– input. Scaling the inorganic nutrients to carbon units, the Pontevedra Ria may be considered as net autotrophic, although the NO3– budget suggests alternation between autotrophy and heterotrophy over an annual cycle.
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spelling doaj.art-4f633d8d0d9d4b6a945c5617453db9a32024-03-03T18:33:49ZengUniversidad Autónoma de Baja CaliforniaCiencias Marinas0185-38802395-90532005-03-01311B10.7773/cm.v31i12.94Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)Andre W Dale0Ricardo Prego1Institute of Marine ResearchInstitute of Marine Research A non-stationary state mass balance of the type advocated by the International Geosphere-Biosphere Programme/Land-Ocean Interactions in the Coastal Zone (IGBP/LOICZ) has been used to assess net ecosystem metabolism in the Pontevedra Ria (NW Spain), a large embayment subject to transient upwelling of Eastern North Atlantic Central Water (ENACW) under favourable meteorological conditions. Nitrate (NO3–) and phosphate (PO43–) data spanning 12 months were resolved at the oceanic boundary by treating the ria as a single box of constant volume. The nutrient budget was scaled up to an estimate of net community production (NCP) using the compositional relationship of local phytoplankton. The mean annual NCP predicted by the NO3– balance was 24.0 mgC m–2 h–1, and 35.8 mgC m–2 h–1 by the PO43– budget. Nutrient fluxes into the reservoir were strongly driven by the incoming oceanic flow throughout the year, which supplied 88% and 98% of the total NO3– and PO43– load, respectively. A high NCP (NO3–) of 57.2 mgC m–2 h–1 was calculated for the height of the growth season contemporaneous with ENACW intrusion, whereas a slightly higher value of 61.4 mgC m–2 h–1 corresponded to PO43–. Nutrient limitation was variable throughout the sampling, switching from PO43– to NO3– from winter to spring concurrent with a drop in riverine PO43– input. Scaling the inorganic nutrients to carbon units, the Pontevedra Ria may be considered as net autotrophic, although the NO3– budget suggests alternation between autotrophy and heterotrophy over an annual cycle. https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/94upwellingnutrient budgetPontevedra RiaNW Spain
spellingShingle Andre W Dale
Ricardo Prego
Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)
Ciencias Marinas
upwelling
nutrient budget
Pontevedra Ria
NW Spain
title Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)
title_full Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)
title_fullStr Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)
title_full_unstemmed Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)
title_short Net autotrophy and heterotrophy in the Pontevedra Ria upwelling system (NW Iberian margin)
title_sort net autotrophy and heterotrophy in the pontevedra ria upwelling system nw iberian margin
topic upwelling
nutrient budget
Pontevedra Ria
NW Spain
url https://www.cienciasmarinas.com.mx/index.php/cmarinas/article/view/94
work_keys_str_mv AT andrewdale netautotrophyandheterotrophyinthepontevedrariaupwellingsystemnwiberianmargin
AT ricardoprego netautotrophyandheterotrophyinthepontevedrariaupwellingsystemnwiberianmargin