Evidence of Global Chlorophyll d

Abstract

Although analyses of chlorophyll d (Chl d)‐dominated oxygenic photosystems have been conducted since their discovery 12 years ago, Chl d distribution in the environment and quantitative importance for aquatic photosynthesis remain to be investigated. We analyzed the pigment compositions of surface sediments and detected Chl d and its derivatives from diverse aquatic environments. Our data show that the viable habitat for Chl d‐producing phototrophs extends across salinities of 0 to 50 practical salinity units and temperatures of 1� to 40�C, suggesting that Chl d production can be ubiquitously observed in aquatic environments that receive near-infrared light. The relative abundances of Chl d derivatives over that of Chl a derivatives in the studied samples are up to 4%, further suggesting that Chl d‐based photosynthesis plays a quantitatively important role in the aquatic photosynthesis.