Publications des scientifiques de l'IRD

Conan P., Pujo-Pay M., Agab M., Calva-Benitez L., Chifflet Sandrine, Douillet Pascal, Dussud C., Fichez Renaud, Grenz C., Mendieta F. G., Origel-Moreno M., Rodriguez-Blanco A., Sauret C., Severin T., Tedetti Marc, Alvarado R. T., Ghiglione J. F. (2017). Biogeochemical cycling and phyto- and bacterioplankton communities in a large and shallow tropical lagoon (Terminos Lagoon, Mexico) under 2009-2010 El Nino Modoki drought conditions. Biogeosciences, 14 (4), p. 959-975. ISSN 1726-4170.

Titre du document
Biogeochemical cycling and phyto- and bacterioplankton communities in a large and shallow tropical lagoon (Terminos Lagoon, Mexico) under 2009-2010 El Nino Modoki drought conditions
Année de publication
2017
Type de document
Article référencé dans le Web of Science WOS:000395322100001
Auteurs
Conan P., Pujo-Pay M., Agab M., Calva-Benitez L., Chifflet Sandrine, Douillet Pascal, Dussud C., Fichez Renaud, Grenz C., Mendieta F. G., Origel-Moreno M., Rodriguez-Blanco A., Sauret C., Severin T., Tedetti Marc, Alvarado R. T., Ghiglione J. F.
Source
Biogeosciences, 2017, 14 (4), p. 959-975 ISSN 1726-4170
The 2009-2010 period was marked by an episode of intense drought known as the El Nino Modoki event. Sampling of the Terminos Lagoon (Mexico) was carried out in November 2009 in order to understand the influence of these particular environmental conditions on organic matter fluxes within the lagoon's pelagic ecosystem and, more specifically, on the relationship between phyto-and bacterioplankton communities. The measurements presented here concern biogeochemical parameters (nutrients, dissolved and particulate organic matter [POM], and dissolved polycyclic aromatic hydrocarbons [PAHs]), phytoplankton (biomass and photosynthesis), and bacteria (diversity and abundance, including PAH degradation bacteria and ectoenzymatic activities). During the studied period, the water column of the Terminos Lagoon functioned globally as a sink and, more precisely, as a "nitrogen assimilator". This was due to the high production of particulate and dissolved organic matter (DOM), even though exportation of autochthonous matter to the Gulf of Mexico was weak. We found that "bottom-up" control accounted for a large portion of the variability of phytoplankton productivity. Nitrogen and phosphorus stoichiometry mostly accounted for the heterogeneity in phytoplankton and free-living prokaryote distribution in the lagoon. In the eastern part, we found a clear decoupling between areas enriched in dissolved inorganic nitrogen near the Puerto Real coastal inlet and areas enriched in phosphate (PO4) near the Candelaria estuary. Such a decoupling limited the potential for primary production, resulting in an accumulation of dissolved organic carbon and nitrogen (DOC and DON, respectively) near the river mouths. In the western part of the lagoon, maximal phytoplankton development resulted from bacterial activity transforming particulate organic phosphorus (PP) and dissolved organic phosphorus (DOP) to available PO4 and the coupling between Palizada River inputs of nitrate (NO3) and PP. The Chumpan River contributed only marginally to PO4 inputs due to its very low contribution to overall river inputs. The highest dissolved total PAH concentrations were measured in the El Carmen Inlet, suggesting that the anthropogenic pollution of the zone is probably related to the oil-platform exploitation activities in the shallow waters of the southern of the Gulf of Mexico. We also found that a complex array of biogeochemical and phytoplanktonic parameters were the driving force behind the geographical distribution of bacterial community structure and activities. Finally, we showed that nutrients brought by the Palizada River supported an abundant bacterial community of PAH degraders, which are of significance in this important oil-production zone.
Plan de classement
Sciences du milieu [021] ; Ecologie, systèmes aquatiques [036]
Description Géographique
MEXIQUE
Localisation
Fonds IRD [F B010069319]
Identifiant IRD
fdi:010069319
Contact