caa a22 4500 445892412 CHVBK 20180317145620.0 cr unu---uuuuu 170323e20110701xx s 000 0 eng 10.1007/s10750-011-0695-3 doi (NATIONALLICENCE)springer-10.1007/s10750-011-0695-3 Light control on phytoplankton production in a shallow and turbid estuarine system [Elektronische Daten] [Carla Gameiro, Juan Zwolinski, Vanda Brotas] Tagus estuary is one of the largest estuaries of Western Europe. With the aim of unravelling the drivers of primary production in this shallow and turbid nutrient replete estuary, we tested the hypothesis that light availability is a major factor controlling phytoplankton production. Environmental parameters, phytoplankton biomass, community composition, and photosynthetic parameters were monitored at two sites in the estuary during a complete annual cycle. Despite the fact that nutrient concentrations were always above growth-limiting values, Chl a concentrations were relatively low throughout the study period. High water column turbidity, due to riverine inputs, promoted a rapid attenuation of light and created a compressed profile with optimal photosynthetic conditions. Therefore, the phytoplankton community, dominated by small cells, such as diatoms and cryptophycean flagellates, displayed highly photosynthetic efficiency and low light-saturated photosynthetic rates as a photo-acclimation response to low light conditions year-round. Primary production rate was unimodal, peaking in the summer months. In such estuarine system, gross primary production could thus be predicted by an existing robust empirical model based on pigment standing crop (Chla), surface irradiance (E 0) and optical depth (Z eup). Compared to other shallow estuaries, the Tagus can be classified as a low- to moderately productive estuary, being the turbidity-induced low light conditions the principal factor limiting phytoplankton growth. Springer Science+Business Media B.V., 2011 P-E curves nationallicence Light limitation nationallicence Photo-Acclimation nationallicence Primary production nationallicence Tagus estuary nationallicence Gameiro Carla Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal aut Zwolinski Juan Instituto de Investigação das Pescas e do Mar (IPIMAR), Av. Brasília, 1449-006, Lisbon, Portugal aut Brotas Vanda Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal aut Hydrobiologia Springer Netherlands 669/1(2011-07-01), 249-263 0018-8158 669:1<249 2011 669 10750 https://doi.org/10.1007/s10750-011-0695-3 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-011-0695-3 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Gameiro Carla Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal aut NATIONALLICENCE 700 1- Zwolinski Juan Instituto de Investigação das Pescas e do Mar (IPIMAR), Av. Brasília, 1449-006, Lisbon, Portugal aut NATIONALLICENCE 700 1- Brotas Vanda Centro de Oceanografia, Faculdade de Ciências da Universidade de Lisboa, Campo Grande, 1749-016, Lisbon, Portugal aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 669/1(2011-07-01), 249-263 0018-8158 669:1<249 2011 669 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer