Are brackish water copepods susceptible to neonicotinoid pesticides? An experimental assessment across different salinity levels

Zooplankton are key organisms in aquatic food webs, but due to spatiotemporal salinity fluctuations, estuarine and brackish lakes support only a limited number of zooplankton species. The susceptibility of zooplankton to pesticide contamination, such as imidacloprid, is particularly important in these ecosystems, because there are fewer species to compensate for losses. However, whether zooplankton in brackish water are truly vulnerable to pesticide contamination is poorly examined. To address this uncertainty, we assessed the vulnerability of the calanoid copepod Sinocalanus tenellus, a dominant zooplankton in the brackish waters of East Asia, to imidacloprid under varying salinity conditions through individual and population-level experiments. The individual-level experiment revealed that both imidacloprid exposure and salinity changes had significant negative effects on the survival rate of S. tenellus. However, hazard assessments indicated that the risk posed by salinity changes was..., , , # Are brackish water copepods susceptible to neonicotinoid pesticides? An experimental assessment across different salinity levels

[https://doi.org/10.5061/dryad.0zpc8676j](https://doi.org/10.5061/dryad.0zpc8676j)

## Description of the data and file structure

### Files and variables

#### File: Acute_toxicity.csv

**Description:** Data set used for performing the Cox proportional hazards model and illustrating the Kaplan-Meier survival curves.

##### Variables

* res: Mortality status of test organisms observed at each time point, where 1 means dead and 0 means alive.
* con: Nominal concentration of imidacloprid in each experimental treatment (μg/L).
* time: Elapsed time since the experiment started (hours).
* salinity: Salinity of experimental water in each treatment (PSU).
* sal_avr: Average salinity of the three sites (Lake Suigetsu, Lake Shinji, and Higashiyachi)
* site: Sampling sites
* sal_dev: Difference between experimental water salinity in each treatment (salinity) and aver...,