caa a22 4500 445891807 CHVBK 20180317145618.0 cr unu---uuuuu 170323e20111101xx s 000 0 eng 10.1007/s10750-011-0746-9 doi (NATIONALLICENCE)springer-10.1007/s10750-011-0746-9 The key role of the chemolimnion in meromictic cenotes of the Yucatan Peninsula, Mexico [Elektronische Daten] [Olmo Torres-Talamante, Javier Alcocer, Patricia Beddows, Elva Escobar-Briones, Alfonso Lugo] This study tests the ecological and physico-chemical effect of sharp density boundaries of meromictic lakes. The investigation was carried out in Nohoch Hol, an anchialine meromictic cenote situated 2.0km inland from the Caribbean coast of the Yucatan Peninsula, Mexico. In situ physico-chemical parameters were recorded with a water quality datalogger at depth intervals of 0.5m. In addition, seven water samples for determination of nutrients, bacterioplankton and phytoplankton in the water column were obtained using SCUBA. Bacterioplankton and phytoplankton densities are low, with concentrations consistent with the oligo- to ultraoligotrophic status of Nohoch Hol indicated by the low nutrient concentrations. The phytoplankton was dominated by the chlorophyte Scenedesmus. Maximum concentrations of bacterio- and phytoplankton were found at 10.0m depth, the top of the chemolimnion. The similarity analysis clustered the samples in three defined groups: (a) the mixolimnion, (b) the mid- and bottom of the chemolimnion and the monimolimnion, and (c) the top of the chemolimnion. The principal component analysis explained over 85% of the total variance in two components (PC). PC1 was related to turbidity and the aggregation of the chlorophytes at the top of the chemolimnion. PC2 was related to dissolved oxygen and the accumulation of filamentous and total bacteria also at the top of the chemolimnion. The top of the chemolimnion acts as a boundary within the water column to the exchange of dissolved and particulate matter between the mixo and the monimolimnion and as an ecological zone with a crucial role in the biogeochemistry of Nohoch Hol. Springer Science+Business Media B.V., 2011 Anchialine nationallicence Tropical lake nationallicence Karst nationallicence Sinkhole nationallicence Anoxia nationallicence Bacterioplankton nationallicence Phytoplankton nationallicence Nutrients nationallicence Torres-Talamante Olmo Colectividad RAZONATURA A.C., Luis G. de León No. 68. Copilco el Alto, Coyoacán, 04360, Mexico, DF, Mexico aut Alcocer Javier Proyecto de Investigación en Limnología Tropical, FES Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, 54090, Tlalnepantla, Estado de México, Mexico aut Beddows Patricia Department of Earth & Planetary Sciences, Northwestern University, 1850 Campus Drive, 60208-2150, Evanston, IL, USA aut Escobar-Briones Elva Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, A.P. 70-305, Ciudad Universitaria, Coyoacán, 04510, Mexico, DF, Mexico aut Lugo Alfonso Proyecto de Investigación en Limnología Tropical, FES Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, 54090, Tlalnepantla, Estado de México, Mexico aut Hydrobiologia Springer Netherlands 677/1(2011-11-01), 107-127 0018-8158 677:1<107 2011 677 10750 https://doi.org/10.1007/s10750-011-0746-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10750-011-0746-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Torres-Talamante Olmo Colectividad RAZONATURA A.C., Luis G. de León No. 68. Copilco el Alto, Coyoacán, 04360, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Alcocer Javier Proyecto de Investigación en Limnología Tropical, FES Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, 54090, Tlalnepantla, Estado de México, Mexico aut NATIONALLICENCE 700 1- Beddows Patricia Department of Earth & Planetary Sciences, Northwestern University, 1850 Campus Drive, 60208-2150, Evanston, IL, USA aut NATIONALLICENCE 700 1- Escobar-Briones Elva Instituto de Ciencias del Mar y Limnología, Universidad Nacional Autónoma de México, A.P. 70-305, Ciudad Universitaria, Coyoacán, 04510, Mexico, DF, Mexico aut NATIONALLICENCE 700 1- Lugo Alfonso Proyecto de Investigación en Limnología Tropical, FES Iztacala, Universidad Nacional Autónoma de México, Av. de los Barrios No. 1, Los Reyes Iztacala, 54090, Tlalnepantla, Estado de México, Mexico aut NATIONALLICENCE 773 0- Hydrobiologia Springer Netherlands 677/1(2011-11-01), 107-127 0018-8158 677:1<107 2011 677 10750 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer