Author, as appears in the article.: Vegas-Vilarrúbia T; Corella J; Pérez-Zanón N; Buchaca T; Trapote M; López P; Sigró J; Rull V

Department: Geografia

URV's Author/s: PEREZ ZANÓN, NÚRIA / Sigró Rodríguez, Francisco Javier

Keywords: Varves Micro-xrf core scanning Meromixis Hypoxia Global warming Anoxia micro-xrf core scanning meromixis hypoxia global warming anoxia

Abstract: © 2017 Recent expansion of anoxia has become a global issue and there is potential for worsening under global warming. At the same time, obtaining proper long-term instrumental oxygen records is difficult, thus reducing the possibility of recording long-term changes in oxygen shifts that can be related with climate or human influence. Varved lake sediments provide the better time frame to study this phenomenon at high resolution. We tracked the oxic/anoxic shifts of the varved Lake Montcortès since 1500 CE, and tried to recognise anthropogenic and climatic influences combining biological and geochemical proxies. Four main scenarios emerged: 1) years with abrupt sediment inputs (A); 2) years with outstanding mixing and oxygenation of the water column (B); 3) years with strong stratification, anoxia, intense sulfur bacterial activity and increased biomass production (C); 4) years with stratification and anoxia, but relatively less biomass production (D). In line with current limnologic trends, high supra-annual variability in the occurrence of oxygenation events was observed. Interestingly, at least 45.3% of the years were mixing years and, like the meromictic ones, were mostly clustered into groups of consecutive years, thus alternating years of monomixis with years of meromixis. Most years of D belong to the period 1500–1820 CE, when human activities were the most intense. Most years of A belonged to the climatic unstable period of 1850–1899 CE. Years of B were irregularly distributed but were best represented in the period 1820–1849 CE. Most years of C belonged to the 20th century. More than 90% of the years with climatic instrumental records belonged to B and C. Current climate warming seems to be taking control over the oxygenation capacity of the lake, especially since the second half of the 20th century. Our results support recent findings related to hypoxia spreading at the global scale.

Research group: Centre en Canvi Climàtic (C3)

Thematic Areas: Zootecnia / recursos pesqueiros Waste management and disposal Saúde coletiva Química Pollution Odontología Nutrição Medicina veterinaria Medicina iii Medicina ii Medicina i Materiais Matemática / probabilidade e estatística Interdisciplinar Historia Geografía Geociências Farmacia Environmental sciences Environmental engineering Environmental chemistry Ensino Engenharias iii Engenharias ii Engenharias i Enfermagem Direito Ciências biológicas iii Ciências biológicas ii Ciências biológicas i Ciências ambientais Ciências agrárias i Ciência de alimentos Ciência da computação Biotecnología Biodiversidade Astronomia / física

licence for use: https://creativecommons.org/licenses/by/3.0/es/

ISSN: 00489697

Author's mail: javier.sigro@urv.cat

Author identifier: 0000-0003-0969-0338

Record's date: 2023-02-19

Papper version: info:eu-repo/semantics/submittedVersion

Link to the original source: https://www.sciencedirect.com/science/article/abs/pii/S0048969717321459?via%3Dihub

Licence document URL: http://repositori.urv.cat/ca/proteccio-de-dades/

Papper original source: Science Of The Total Environment. 612 1577-1592

APA: Vegas-Vilarrúbia T; Corella J; Pérez-Zanón N; Buchaca T; Trapote M; López P; Sigró J; Rull V (2018). Historical shifts in oxygenation regime as recorded in the laminated sediments of lake Montcortès (Central Pyrenees) support hypoxia as a continental-scale phenomenon. Science Of The Total Environment, 612(), 1577-1592. DOI: 10.1016/j.scitotenv.2017.08.148

Article's DOI: 10.1016/j.scitotenv.2017.08.148

Entity: Universitat Rovira i Virgili

Journal publication year: 2018

Publication Type: Journal Publications