RT journal article
T1 Size fractionated phytoplankton biomass and net metabolism along a tropical estuarine gradient
A1 Soria Píriz, Sara
A1 García Robledo, Emilio Guillermo
A1 Papaspyrou, Sokratis
A1 Aguilar, Virginia
A1 Seguro, Isabel
A1 Acuña, J.
A1 Morales, Alvaro
A1 Corzo Rodríguez, Alfonso
A2 Biología
AB Size structure of phytoplankton determines to a large degree the trophic interactions in oceanic and coastal waters and eventually the destiny of its biomass. Although, tropical estuarine systems are some of the most productive systems worldwide compared to temperate systems, little is known about phytoplankton biomass size fractions, their contribution to net metabolism, or the ecological factors driving phytoplankton size distribution in tropical estuaries. Hence, we measured the size-fractionated biomass and net metabolism of the plankton community along a salinity and nutrient gradient in the Gulf of Nicoya estuary (Costa Rica), during the dry season. Respiration (23.6 mmol O2 m−3 h−1) was highest at the estuary head, whereas maximum net primary production (23.1 mmol O2 m−3 h−1) was observed in the middle of the estuary, coinciding with the chlorophyll a maximum (15.9 mg m−3). Thus, only the middle section of the estuary was net autotrophic (2.9 g C m−2 d−1), with the rest of the estuary being net heterotrophic. Regression analysis identified light availability, and not nutrients, as the principal factor limiting primary production in the estuary due to increased turbidity. The changes in net metabolism along the estuary were also reflected in the phytoplankton's size structure. Although micro- and picophytoplankton were the most productive fractions overall, in the middle section of the estuary nanophytoplankton dominated primary production, chlorophyll, and autotrophic biomass.
SN 0024-3590
YR 2017
FD 2017-04-21
LK http://hdl.handle.net/10498/35237
UL http://hdl.handle.net/10498/35237
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 08-nov-2026