# Spatial and Temporal Variations in the Trophic Structure of Fish Assemblages in the Eastern Region of the Yellow Sea Determined by C- and N-Stable Isotope Ratios

## TL;DR

This study used carbon and nitrogen isotopes to explore how fish diets and food sources vary across locations and seasons in the Yellow Sea, finding phytoplankton as a key energy source.

## Contribution

The study reveals spatial and seasonal isotopic niche shifts in fish assemblages, linking them to local prey availability and environmental conditions.

## Key findings

- δ13C and δ15N values showed significant spatial and seasonal variation without consistent trends.
- Phytoplankton-derived organic matter was identified as the primary energy source in the food web.
- Isotopic niche shifts reflect local differences in prey availability and hydrographic conditions.

## Abstract

This study examined spatial and seasonal variations in the trophic structure of fish assemblages in the eastern Yellow Sea using carbon and nitrogen stable isotopes. Significant differences in δ13C and δ15N values were found among sites and seasons, though no consistent trend emerged. Phytoplankton-derived organic matter was identified as the main energy source for the regional food web. These findings improve understanding of how environmental changes influence marine trophic dynamics and support ecosystem-based fisheries management in the Yellow Sea.

This study aimed to determine how spatial and seasonal variations influence the trophic structure of fish assemblages in the eastern Yellow Sea during 2023. Carbon and nitrogen stable isotope analyses revealed significant but spatially variable differences in δ13C and δ15N values among seasons and sites, without consistent overarching trends. These results suggest that phytoplankton-derived organic matter predominantly supports the regional food web, with isotopic niche shifts reflecting local differences in prey availability and hydrographic conditions. The findings contribute to the development of adaptive, ecosystem-based fishery management strategies amid increasing anthropogenic and climatic pressures.