Please use this identifier to cite or link to this item: http://hdl.handle.net/2122/9169
AuthorsCabassi, J.* 
Tassi, F.* 
Mapelli, F.* 
Borin, S.* 
Calabrese, S.* 
Rouwet, D.* 
Chiodini, G.* 
Pecoraino, G.* 
Caliro, S.* 
TitleGeosphere-biosphere interacions in bio-activity volcanic lakes: evidences from Hule and Rìo Cuarto (Costa Rica).
Issue Date19-Jun-2014
Series/Report no.7/9 (2014)
DOI10.1371/journal.pone.0102456
URIhttp://hdl.handle.net/2122/9169
Keywordsbio activity, volcanic lakes, costa rica
Subject Classification03. Hydrosphere::03.04. Chemical and biological::03.04.06. Hydrothermal systems 
AbstractHule and Rı´o Cuarto are maar lakes located 11 and 18 km N of Poa´s volcano along a 27 km long fracture zone, in the Central Volcanic Range of Costa Rica. Both lakes are characterized by a stable thermic and chemical stratification and recently they were affected by fish killing events likely related to the uprising of deep anoxic waters to the surface caused by rollover phenomena. The vertical profiles of temperature, pH, redox potential, chemical and isotopic compositions of water and dissolved gases, as well as prokaryotic diversity estimated by DNA fingerprinting and massive 16S rRNA pyrosequencing along the water column of the two lakes, have highlighted that different bio-geochemical processes occur in these meromictic lakes. Although the two lakes host different bacterial and archaeal phylogenetic groups, water and gas chemistry in both lakes is controlled by the same prokaryotic functions, especially regarding the CO2-CH4 cycle. Addition of hydrothermal CO2 through the bottom of the lakes plays a fundamental priming role in developing a stable water stratification and fuelling anoxic bacterial and archaeal populations. Methanogens and methane oxidizers as well as autotrophic and heterotrophic aerobic bacteria responsible of organic carbon recycling resulted to be stratified with depth and strictly related to the chemical-physical conditions and availability of free oxygen, affecting both the CO2 and CH4 chemical concentrations and their isotopic compositions along the water column. Hule and Rı´o Cuarto lakes were demonstrated to contain a CO2 (CH4, N2)-rich gas reservoir mainly controlled by the interactions occurring between geosphere and biosphere. Thus, we introduced the term of bio-activity volcanic lakes to distinguish these lakes, which have analogues worldwide (e.g. Kivu: D.R.C.-Rwanda; Albano, Monticchio and Averno: Italy; Pavin: France) from volcanic lakes only characterized by geogenic CO2 reservoir such as Nyos and Monoun (Cameroon).
Appears in Collections:Papers Published / Papers in press

Show full item record

Page view(s)

117
Last Week
0
Last month
0
checked on Jul 23, 2017

Download(s)

52
checked on Jul 23, 2017

Google ScholarTM

Check

Altmetric