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Environmental influences on living marine stromatolites: insights from benthic microalgal communities
Author(s) -
Rishworth Gavin M.,
Elden Sean,
Perissinotto Renzo,
Miranda Nelson A. F.,
Steyn PaulPierre,
Bornman Thomas G.
Publication year - 2016
Publication title -
environmental microbiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.954
H-Index - 188
eISSN - 1462-2920
pISSN - 1462-2912
DOI - 10.1111/1462-2920.13116
Subject(s) - stromatolite , biology , benthic zone , cyanobacteria , ecological succession , algae , tufa , dominance (genetics) , ecology , carbonate , phylum , microbial mat , oceanography , paleontology , geology , biochemistry , materials science , bacteria , gene , metallurgy
Summary Extant marine stromatolites act as partial analogues of their A chaean counterparts, but are rare due to depleted ocean calcium carbonate levels and suppression by eukaryotic organisms. Unique, peritidal tufa stromatolites at the interface between marine and freshwater inputs were discovered in S outh A frica in the past decade. Our aim was to investigate the benthic microalgal community (green algae, diatoms and cyanobacteria ) of these stromatolites to assess succession and dominance patterns using real‐time, in situ measurements of algal concentrations and composition. These biological measurements were modelled using generalized linear modelling ( GLM ) multivariate statistics against water physical and chemical parameters measured at regular monthly intervals, from J anuary to D ecember 2014. Salinity peaked and temperature dipped in winter, with both correlated to microalgal community change ( GLM : P < 0.01). Diatoms and cyanobacteria , which construct the stromatolites, were consistently the dominant groups within the algal community, with minimal green algae present throughout the year. Importantly, this demonstrates a unique, relatively stable microalgal stromatolite community as opposed to those of other marine stromatolites, which likely require seasonal and stochastic disturbance to persist. This has implications in terms of interpreting community succession and differential layering in modern and fossilized stromatolites respectively.