RT journal article
T1 Intertidal microphytobenthic primary production and net metabolism of a tropical estuary
A1 Corzo Rodríguez, Alfonso
A1 Haro Páez, Sara
A1 Gomez Ramirez, Eddy
A1 González Mejías, Carlos José
A1 Papaspyrou, Sokratis
A1 García Robledo, Emilio Guillermo
A2 Biología
A2 Física Aplicada
K1 Intertidal mudflat
K1 Microphytobenthic primary production
K1 Microphytobenthos
K1 Nicoya gulf
K1 Tempisque estuary
K1 Tropical estuary
AB Tidal flats are inhabited by benthic microalgae (microphytobenthos, MPB) supporting important ecosystem functions and services. Studies on MPB have been conducted mainly in temperate systems, despite that the majority of tidal flats on Earth are found in the tropical zone (∼55%). To fill this gap of knowledge and evaluate the contribution of tidal flat MPB in one of the most productive estuaries worldwide, sediment cores were collected from 14 stations along the inner Gulf of Nicoya (Costa Rica) at different tidal heights or sea levels (SL) from October 2013 to April 2014. MPB abundance, using chlorophyll a (Chla) biomass as a proxy, and net primary production (PN) and dark respiration (RD), using O2 microsensors, were measured together with other sediment biogeochemical variables in muddy and sandy sediments. Landsat-8 satellite images were used to map the extension of tidal flats and the abundance of MPB using Normalized Difference Vegetation Index (NDVI) as a proxy. Chla ranged from 0.45 to 7.45 μg cm−2, with higher concentrations observed closer to the river mouth. There was no significant correlation between Chla and SL nor with any other sediment physicochemical variable. MPB abundance estimated by remote sensing displayed considerable spatial heterogeneity, both within and among tidal flats, and clear seasonal differences with higher abundance during the rainy season. PN ranged between 0.8 and 8.6 mmol O2 m−2 h−1, being positively correlated to SL and to the accumulated rain during 30 days prior to the sampling date and inversely to the mean irradiance at noon during the previous month. Daily net community metabolism estimated from PN and RD data and converted to carbon fixation rates indicates that the unvegetated tidal flats of the gulf contribute as much as the total input of allochthonous C from the Tempisque River. However, the results presented here have to be confirmed with direct measurements of C transfer, including the contribution of the adjacent mangrove system. Such studies are crucial to assess the local, regional and global importance of production and other ecosystem services by MPB in tropical areas.
PB Elsevier Ltd.
SN 1879-0291
YR 2024
FD 2024
LK http://hdl.handle.net/10498/35724
UL http://hdl.handle.net/10498/35724
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 06-nov-2026