Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters

Jellyfish blooms are increasing globally in frequency and intensity, introducing complex ecological interactions, yet the mechanisms by which they alter ecosystem structure remain poorly characterized due to a lack of sustained field observations.
We conducted targeted time-series observations in Jiaozhou Bay—a representative coastal ecosystem experiencing Aurelia coerulea blooms—tracking temporal responses of plankton communities and trophic interactions to jellyfish population fluctuations. A total of 36 surveys were conducted over three years from 2021 to 2023, yielding comprehensive datasets on biological variables (jellyfish biomass, zooplankton abundance and composition, phytoplankton abundance and composition), environmental factors (temperature, salinity, pH), and nutrient concentrations in the study area. Additionally, we obtained datasets on the gastric content composition of field-collected A. coerulea through stomach dissection analysis. We further quantified the dual roles ..., 1. Study area and investigated time
Jiaozhou Bay, located in the Yellow Sea, China, is a shallow, semi-enclosed coastal system that is heavily influenced by anthropogenic activities The study area (mean depth of ~4 m) has been established as a reference site for long-term ecological monitoring (Sun et al., 2011). It also serves as a nursery ground for Aurelia coerulea and experiences recurrent seasonal jellyfish blooms (Wang et al., 2021), making it representative for assessing the ecological impacts of jellyfish blooms in Jiaozhou Bay. From 2021 to 2023, we implemented a fixed site temporal monitoring program to control spatial variability, synchronously capturing coupled measurements of environmental conditions, jellyfish biomass, plankton communities, and nutrient dynamics. Given the strong seasonality and interannual variability of A. coerulea blooms (Wang and Sun, 2015), multiyear, site-specific monitoring allowed us to capture temporal ecological responses while eliminating spatia..., # Jellyfish blooms restructure plankton dynamics and trophic linkages in coastal waters

Dataset DOI: [10.5061/dryad.gqnk98t38](https://doi.org/10.5061/dryad.gqnk98t38)

## Description of the data and file structure

We have submitted the following raw data files:

* `gut_content_analysis.xlsx`: Contains data on the stomach contents of *Aurelia coerulea*, including sampling year, month, study area, jellyfish umbrella diameter (mm), and the number of copepods identified via dissection.
* `temperature_salinity_pH_nutrient.xlsx`: Includes triplicate measurements of basic environmental parameters collected during each survey, including temperature, salinity, pH, and concentrations of five nutrients (silicate, phosphate, nitrate, nitrite, and ammonium; unit: μmol L⁻¹) in the water column.
* `phytoplankton_zooplankton_jellyfish_Chlorophyll_a.xlsx`: Provides biological data, including:
* Abundance of phytoplankton (dinoflagellates and diatoms; ind L⁻¹) and chlorophyll a concentration (μg L⁻¹..., ,