Thaliacean Community Dominance Shift in the Northern South China Sea

Thaliaceans are jelly-like ocean animals that play an important role in the carbon cycle and the food web. In this study, we investigate how two major groups of thaliaceans, doliolids and salps, respond to different marine conditions from five years of observations in the northern South China Sea. We found that the two groups occupy distinct habitats, with doliolids being most common in coastal waters influenced by freshwater input and nutrient-rich conditions, while salps were more common in saltier offshore waters. Rainy years provided more suitable conditions for doliolids, while dry years favored salps in the Pearl River Estuary. These results demonstrate that changes in rainfall and ocean conditions can shift the balance between these thaliacean groups. This knowledge can help improve predictions of how marine ecosystems respond to climate variability.