Unveiling differential thermal sensitivities in marine phytoplankton within the China Seas

Abstract

Abstract In this study, we explored the realized thermal sensitivities of various phytoplankton groups in natural seawater, a crucial aspect for understanding the dynamics of marine ecosystems under climate change. Utilizing a decadal pigment dataset (2002–2015) from China Seas and employing generalized additive mixed models coupled with maximum entropy modeling, we discerned thermal sensitivity differentiations among nine phytoplankton groups, encompassing the full‐size spectrum. Our findings revealed that cryptophytes were exceptionally thermally sensitive, with a strong correlation between temperature changes and biomass variance. Characterized by a preference for cooler waters, cryptophytes had a low mean temperature niche and a narrow niche breadth. Notably, they exhibited the lowest temperature tipping point, highlighting their heightened vulnerability to warming trends. These findings underscored the significance of cryptophytes, an often‐overlooked group, in understanding ecosystem responses to climate shifts, and emphasized their potential role as key indicators in marine ecological studies under global warming.