Environmental forcing of phytoplankton carbon-to-diversity ratio and carbon-to-chlorophyll ratio: A case study in Jiaozhou Bay, the Yellow Sea

The relationships between phytoplankton carbon (C) biomass and diversity (i.e., C-to-H ' ratio) and chlorophyll a (i.e., C-to-Chl a ratio) are good indicators of marine ecosystem functioning and stability. Here we conducted four cruises spanning 2 years in Jiaozhou Bay to explore the dynamics of C-to-H ' and C-to-Chl a ratios. The results showed that the phytoplankton C biomass and diversity were dominated by diatoms, followed by dinoflagellates. The average C-to-H ' ratio ranged from 84.10 to 912.17, with high values occurring in the northern region of the bay. In contrast, the average C-to-Chl a ratio ranged between 15.55 and 89.47, and high values primarily appeared in the northern or northeastern part of the bay. In addition, the redundancy analysis showed that temperature and phosphate (DIP) were significantly correlated with both ratios in most cases, indicating that temperature and DIP may be key factors affecting the dynamics of C-to-H ' and C-to-Chl a ratios.

Automated summary

The relationships between phytoplankton biomass and diversity and the ratios of carbon-to-hydrogen and carbon-to-chlorophyll a are important indicators of marine ecosystem functioning and stability. This study conducted multiple cruises in Jiaozhou Bay and found that diatoms and dinoflagellates are the dominant phytoplankton species in terms of biomass and diversity. Temperature and phosphate were identified as significant factors affecting the dynamics of the carbon-to-hydrogen and carbon-to-chlorophyll a ratios.