Limnology and plankton diversity of salt lakes from Transylvanian Basin (Romania): A review

  • Mircea Alexe Babes-Bolyai University, Department of Physical and Technical Geography, Romania.
  • Gheorghe Șerban | gheorghe.serban@ubbcluj.ro Babes-Bolyai University, Department of Physical and Technical Geography, Romania.
  • Andreea Baricz National Institute of Research and Development for Biological Sciences (NIRDBS), Romania.
  • Adrian-Ștefan Andrei Biology Center of the Academy of Sciences of the Czech Republic, Department of Aquatic Microbial Ecology, Czechia.
  • Adorján Cristea Babes-Bolyai University, Department of Molecular Biology and Biotechnology, Romania.
  • Karina P. Battes Babes-Bolyai University, Department of Taxonomy and Ecology, Romania.
  • Mirela Cîmpean Babes-Bolyai University, Department of Taxonomy and Ecology, Romania.
  • Laura Momeu Babes-Bolyai University, Department of Taxonomy and Ecology, Romania.
  • Vasile Muntean Babes-Bolyai University, Department of Molecular Biology and Biotechnology, Romania.
  • Sebastian A. Porav Babes-Bolyai University, Electron Microscopy Center, Romania.
  • Horia L. Banciu Babes-Bolyai University, Center for Systems Biology, Biodiversity, and Bioresources, Romania.

Abstract

In the present work, we review the current knowledge on genesis, limnology and biodiversity of salt lakes distributed around the inner contour of Eastern Carpathian arc (Transylvanian Basin, Central Romania). Transylvanian salt lakes formed on ancient halite (NaCl) deposits following natural processes or quarrying activities.  Most of these lakes are located in eastern (Sovata area), southern (Ocna Sibiului), and western (Turda-Cojocna) parts of the Transylvanian Basin, have small surfaces (0.1-4 ha), variable depths (2-100 m), are hypersaline (>10%, w/v, total salts, mainly NaCl) and permanently stratified. As consequence of steady salinity/density gradient, heat entrapment below surface layer (i.e., heliothermy) develops in several Transylvanian lakes. The physical and chemical water stratification is mirrored in the partition of plankton diversity. Lakes with less saline (2-10% salinity) water layers appear to harbor halotolerant representatives of phyto- (e.g., marine native Picochlorum spp. and Synechococcus spp.), zoo- (e.g., Moina salina), and bacterioplankton (e.g., Actinobacteria, Verrucomicobia), whereas halophilic plankton communities (e.g., green algae Dunaliella sp., brine shrimp Artemia sp., and members of Halobacteria class) dominate in the oxic surface of hypersaline (>10% salinity) lakes. Molecular approaches (e.g., PCR-DGGE, 16S rRNA gene-based clone libraries, and DNA metabarcoding) showed that the O2-depleted bottom brines of deep meromictic Transylvanian lakes are inhabited by known extremely halophilic anaerobes (e.g. sulfate-reducing Delta-Proteobacteria, fermenting Clostridia, methanogenic and polymer-degrading archaea) in addition to representatives of uncultured/unclassified prokaryotic lineages. Overall, the plankton communities thriving in saline Transylvanian lakes seem to drive full biogeochemical cycling of main elements. However, the trophic interactions (i.e., food web structure and energy flow) as well as impact of human activities and predicted climate changes are yet to be assessed in these unique ecosystems with little or no match to analogous salt lakes worldwide.  

Dimensions

Altmetric

PlumX Metrics

Downloads

Download data is not yet available.

Author Biography

Mircea Alexe, Babes-Bolyai University, Department of Physical and Technical Geography
Department of Physical and Technical Geography
Published
2017-09-18
Info
Issue
Section
Reviews
Keywords:
Biodiversity, halite, halophilic, hypersaline, meromictic lake, picophytoplankton, zooplankton.
Statistics
  • Abstract views: 3141

  • PDF: 641
  • Supplementary: 199
  • HTML: 644
How to Cite
1.
Alexe M, Șerban G, Baricz A, Andrei A- Ștefan, Cristea A, P. Battes K, Cîmpean M, Momeu L, Muntean V, Porav SA, Banciu HL. Limnology and plankton diversity of salt lakes from Transylvanian Basin (Romania): A review. J Limnol [Internet]. 2017Sep.18 [cited 2020Jul.11];77(1). Available from: https://www.jlimnol.it/index.php/jlimnol/article/view/jlimnol.2017.1657