Identifying patterns in the multitrophic community and food-web structure of a low-turbidity temperate estuarine bay

Trophic response of fishes to rainfall variability in a temperate estuarine system of Korea: A stable isotope approach

To assess the basal resources supporting food webs impacted by rainfalls, we compared stable isotope ratios (δ¹³C and δ¹⁵N) of fish consumers and organic matter sources between up- and down-sites in an estuary between seasons (June and September) and years (2018 and 2019) that showed different patterns of summer monsoon. Our study showed seasonal differences in the δ¹³C and δ¹⁵N values of basal resources and fish consumers in both years. At the up-site, significant differences of δ¹³C values of fish consumers were found between years, resulting from changing rainfall period, thereby causing a shift in food availability from terrigenous organic matter to periphyton. In contrast, at the down-site, the consistent isotopic values of fishes were observed in both years, suggesting that rainfall shift has a negligible impact on resources for fishes. Overall, the annual shift in resources for fishes in the estuary may be controlled by contrasting rainfall events.

Recovery of Macrobenthic Food Web on Rocky Shores Following the Hebei Spirit Oil Spill as Revealed by C and N Stable Isotopes

The impact of large-scale oil spills on organisms can lead to modifications of the food web structure. To assess the effects of the Hebei Spirit oil-spill accident on the trophic structure of the macrobenthic community on intertidal rocky shores along Taean Peninsula on the western coast of Republic of Korea 4 years after the Hebei Spirit oil spill, we analyzed carbon and nitrogen stable isotope ratios of macrobenthic consumers and their potential food sources in two heavily oil-impacted and one non-impacted sites. The results show no significant differences in isotopic ratios of feeding groups and their potential food sources between the polluted and reference sites, suggesting similar trophic structures given similar resource use by consumers. Similar isotopic niches and substantial overlap areas of feeding groups between the affected and reference sites suggest that the oil-impacted sites have re-achieved the trophic functions of the natural ecosystem. This study provides valuable information on the ecological processes of trophic recovery in coastal ecosystems impacted by oil spills.