Dataset from a mesocosm experiment assessing the effects of a simulated terrestrial runoff on the plankton food web in a Mediterranean lagoon

Due to climate change, the frequency and intensity of extreme rainfall events are increasing in the Mediterranean region. As a result, terrestrial runoffs are expected to occur more frequently in the future, potentially impacting coastal aquatic ecosystems. The aim of this study was to assess the effects of a simulated terrestrial runoff on all components of the planktonic food web.
In May 2021, an in situ mesocosm experiment was conducted in the Mediterranean Thau Lagoon. To simulate terrestrial runoff within the mesocosms, a mixture of forest soil (collected from the Puéchabon state forest; 43°44’29’’N, 3°35’45’’E) and river water (from the La Vène River; 43°30'56.4"N, 3°41'33.5"E) was added.
For 18 consecutive days, we monitored planktonic communities in both control and runoff-simulated mesocosms to determine their responses. The dataset resulting from this experiment include:
- chlorophyll-a concentrations measured by HPLC,
- cytometric populations (viruses, bacteria, cyanobacteria, picophytoplankton, nanophytoplankton, and heterotrophic nanoflagellates),
- taxonomic composition and abundances of phytoplankton and protozooplankton identified using an inverted microscope,
- taxonomic abundances of metazooplankton assessed using a macroscope.