Shifting resource utilization of the lacustrine shrimp Palaemon paucidens in temperate coastal lagoons of Korea as revealed by stable isotopes

Seasonal variations in biochemical and stable isotope compositions of particulate organic matter in two contrasting temperate coastal lagoons of Korea

“…The dominance of PCHO is likely due to a major contribution of terrestrial matter to the POM pool, as shown by the lower d 13 C values at most sampling sites, which may be linked to freshwater inputs from upstream. As terrestrial and marsh plant-derived organic matter is known to have very low d 13 C values, ranging between −23‰ and −30‰ (Fry and Sherr, 1984;Park et al, 2020), the high concentrations of PCHO support this explanation. In addition, the presence of POM in PPr and PLip has been reported to increase the number of phytoplanktonic cells along with phytoplankton blooms (Pusceddu et al, 1996).…”

“…The Hyangho sites were characterized by oligohaline conditions, whereas the Gyeongpoho sites exhibited a wide range of salinity from nearly freshwater to hypersaline seawater. At the Gyeongpoho sites, the POM composition may reflect the spatial variation in d 13 C values with a diverse mixture of organic matter sources along the salinity gradient (Park et al, 2020). In contrast, the 13 C-depletion of POM at the Hyangho sites may be explained by freshwater-dominated conditions resulting from the blocking of seawater intrusion by the presence of sand bars during most of the sampling periods.…”

“…At the Gyeongpoho site, the lowest d 13 C values of POM were recorded immediately after the monsoon period, which may reflect the input of terrestrial organic matter by heavy rainfall (Riera and Richard, 1996;Berto et al, 2013). The input of terrestrial organic matter is known to increase the trophic contribution to consumer production at the upper site of Gyeongpoho, and macroalgal blooms caused by nutrient enrichment can also appear after the monsoon period (Park et al, 2020). For Gyeongpoho, the highly variable salinity was positively correlated with the d 13 C values of POM.…”

“…The artificial channel allows for continuous exchange of freshwater with seawater, which increases the freshwater's salinity. In contrast, Hyangho has an area of 0.14 km 2 , and is usually separated from the sea by sand dunes, but is seasonally connected to the sea by a channel generated by heavy rainfall during summer monsoons (Park et al, 2020).…”

“…Gyeongpoho and Hyangho, located adjacent to each other, have different ecological environments due to their hydrological characteristics (Park et al, 2020). However, there is no study on spatiotemporal variations in carbon and nitrogen dynamics of POM that could explain the ecosystem structure and function of the lagoons as a transition zone between ocean and land (Chen et al, 2021;Lu et al, 2022).…”