Assessing the response of micro-eukaryotic diversity to the Great Acceleration using lake sedimentary DNA

Abstract

Long-term time series have provided evidence that anthropogenic pressures can threaten lakes. Yet it remains unclear how and the extent to which lake biodiversity has changed during the Anthropocene, in particular for microbes. Here, we used DNA preserved in sediments to compare modern micro-eukaryotic communities with those from the end of the 19th century, i.e., before acceleration of the human imprint on ecosystems. Our results obtained for 48 lakes indicate drastic changes in the composition of microbial communities, coupled with a homogenization of their diversity between lakes. Remote high elevation lakes were globally less impacted than lowland lakes affected by local human activity. All functional groups (micro-algae, parasites, saprotrophs and consumers) underwent significant changes in diversity. However, we show that the effects of anthropogenic changes have benefited in particular phototrophic and mixotrophic species, which is consistent with the hypothesis of a global increase of primary productivity in lakes.

Lake Sedimentary DNA Research on Past Terrestrial and Aquatic Biodiversity: Overview and Recommendations

“…The use of long-term sedaDNA now offers the possibility to study the impact of climatic, environmental, and anthropogenic perturbations on aquatic biota e.g., [11,34,65]. This approach provides information about Holocene and Late Pleistocene biota, including taxa that leave no morphologically identifiable remains preserved in lakes (see [13] for review).…”

Structural Characteristics and Driving Factors of the Planktonic Eukaryotic Community in the Danjiangkou Reservoir, China

“…With the advent and improvement of high-throughput sequencing technology [7], eukaryotic diversity can be evaluated. High-throughput sequencing of specific PCR products, such as eukaryotic 18S rDNA genes, on such platforms, can be used to obtain information on eukaryotic community structure, evolutionary relationships, and correlations between eukaryotic plankton and the environment [8][9][10][11]. Molecular biology has been widely used in studying plankton in water [12][13][14][15][16].…”

Sediment archives reveal irreversible shifts in plankton communities after World War II and agricultural pollution

“…To evaluate the stability and resilience 1 of coastal ecosystem communities to perturbations that occurred during the Anthropocene, 2 pre-industrial biodiversity baselines inferred from paleoarchives are needed. 3,4 The study of ancient DNA (aDNA) from sediments (sedaDNA) 5 has provided valuable information about past dynamics of microbial species 6-8 and communities [9][10][11][12][13][14][15][16][17][18] in relation to ecosystem variations. Shifts in planktonic protist communities might significantly affect marine ecosystems through cascading effects, [19][20][21] and therefore the analysis of this compartment is essential for the assessment of ecosystem variations.…”

“…37,43 SedaDNA analyses of plankton have shown its potential as a tool for studying the effect of human perturbation on biological communities. 18,[43][44][45][46] Paleogenetic analyses revealed long-term shifts in plankton sometimes proving anthropogenic influence 9,10,12,13,17 and the irreversibility of those changes. 47,48 SedaDNA analyses have highlighted the increase and recrudescence of harmful algal bloom species in lakes 49 and coastal waters 7,8 and reflected an increase in eutrophication due to human pressures.…”