Impacts of environmental drivers on the temporal dynamics of phytoplankton diversity during toxic cyanobacterial blooms

Toxic cyanobacteria have become a regular threat to freshwater ecosystems in recent decades. Their proliferation is attributed to various climate change stressors such as increased nutrient levels and higher temperatures. Nevertheless, the exact conditions necessary to instigate a bloom, and particularly their toxicity, are still unclear. To better understand the dynamics of a bloom, it is important to look at the changes in diversity of cyanobacterial species and their competitors throughout the development of a bloom. Moreover, these diversity patterns can be linked to the timing when a cyanobacterial bloom builds up, peaks, and breaks down, as well as to changes in the environmental conditions.

From May till October 2023, samples were collected weekly from three Dutch lakes: Grote Plas, Braasemermeer and Veerplas. Throughout this period, blooms happened in these lakes at different times. Data was collected for a wide range of abiotic and biotic factors (pH, light attenuation, dissolved oxygen levels, chlorophyll a content, DOC, DIC, TN, TP and more). And samples were filtered for DNA analysis.

This student project will consist of the first phase of labwork to perform the 16S and 18S metabarcoding. This phase of the project will take place at the Netherlands Institute of Ecology (NIOO-KNAW) in Wageningen. The second phase of the project will be to run the community composition analysis using bioinformatic tools like Qiime2 and RStudio as well as use statistical analysis to find correlations between the community composition changes over time with the available environmental data.

Skills learned:

• Molecular labwork: DNA extraction, primer selection, PCR amplification, barcode attachment
• Bioinformatics: Qiime2 for cleaning and prepping the raw sequence data, RStudio for community composition analysis and statistical tests.

Duration: 6 months or longer

Start date: Any time after 1 October 2023

The internshop is for a MSc student