Bacterial secondary production and it relation with primary production in the Embalse del Río III Reservoir, Argentina

Hydrobiologia ◽  
1991 ◽  
Vol 211 (1) ◽  
pp. 57-64 ◽  
Author(s):  
Aldo A. Mariazzi ◽  
Miguel A. Di Siervi ◽  
Jorge L. Donadelli
Keyword(s):  
Primary Production ◽  
Secondary Production ◽  
Del Rio ◽  
Bacterial Secondary Production

scholarly journals EFECTOS DE LA RECOMUNICACIÓN DEL RÍO MAGDALENA CON SU ANTIGUO DELTA: CAMBIOS EN LA PRODUCCIÓN PRIMARIA FITOPLANCTÓNICA Y RESPIRACIÓN EN EL COMPLEJO PAJARALES, 1989 A 2005

2016 ◽  
Vol 38 (2) ◽  
Author(s):  
Johan D. Rodríguez Chila ◽  
José E. Mancera Pineda ◽  
Héctor J. López Salgado
Keyword(s):  
Organic Matter ◽  
Experimental Design ◽  
Primary Production ◽  
Net Primary Production ◽  
Nutrient Inputs ◽  
Phytoplankton Primary Production ◽  
Physical Chemical ◽  
Magdalena River ◽  
Del Rio ◽  
Associated Variables

The phytoplankton primary production, pelagic respiration, photosynthetic pigments, and physical-chemical associated variables in the Pajarales Complex, were estimated to assess the potential effects of the Magdalena River recommunication with its former delta, The study carried out between September and December 2005, followed the same experimental design than one done before to the recommunication The results show a signicant increase of the net primary production when compared with the years 1988-89 (from 598 gC/m2/year to 982 gC/m2/year). The actual production seems to be driven mainly by ammonia, and there is no correlation neither with the water transparency nor the chlorophyll a concentration. The ecosystem is less efcient in the synthesis of organic matter after the recommunication with the Magdalena river. The respiration rate increased, showing higher and more prolonged heterotrophy, which may be associated to higher organic matter and inorganic nutrient inputs from the Magdalena River. The results conrm eutrophication increase in the CP between 1989 and 2005.

scholarly journals Sea-ice associated carbon flux in Arctic spring

Elem Sci Anth ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
J. Ehrlich ◽  
B. A. Bluhm ◽  
I. Peeken ◽  
P. Massicotte ◽  
F. L. Schaafsma ◽  
...  
Keyword(s):  
Sea Ice ◽  
Primary Production ◽  
Carbon Flux ◽  
Secondary Production ◽  
Environmental Changes ◽  
Ice Algae ◽  
Carbon Demand ◽  
Algal Material ◽  
Source Sink ◽  
Ice Water

The Svalbard region faces drastic environmental changes, including sea-ice loss and “Atlantification” of Arctic waters, caused primarily by climate warming. These changes result in shifts in the sea-ice-associated (sympagic) community structure, with consequences for the sympagic food web and carbon cycling. To evaluate the role of sympagic biota as a source, sink, and transmitter of carbon, we sampled pack ice and under-ice water (0–2 m) north of Svalbard in spring 2015 by sea-ice coring and under-ice trawling. We estimated biomass and primary production of ice algae and under-ice phytoplankton as well as biomass, carbon demand, and secondary production of sea-ice meiofauna (>10 µm) and under-ice fauna (>300 µm). Sea-ice meiofauna biomass (0.1–2.8 mg C m–2) was dominated by harpacticoid copepods (92%), nauplii (4%), and Ciliophora (3%). Under-ice fauna biomass (3.2–62.7 mg C m–2) was dominated by Calanus copepods (54%). Appendicularia contributed 23% through their high abundance at one station. Herbivorous sympagic fauna dominated the carbon demand across the study area, estimated at 2 mg C m–2 day–1 for ice algae and 4 mg C m–2 day–1 for phytoplankton. This demand was covered by the mean primary production of ice algae (11 mg C m–2 day–1) and phytoplankton (30 mg C m–2 day–1). Hence, potentially 35 mg C m–2 day–1 of algal material could sink from the sympagic realm to deeper layers. The demand of carnivorous under-ice fauna (0.3 mg C m–2 day–1) was barely covered by sympagic secondary production (0.3 mg C m–2 day–1). Our study emphasizes the importance of under-ice fauna for the carbon flux from sea ice to pelagic and benthic habitats and provides a baseline for future comparisons in the context of climate change.

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