ABSTRACT

The significant enrichment of chemical composition associated with enhanced bioactivities and an increased number of bio-particles in the sea-surface microlayer (SML) were observed in the high-nutrient, low-chlorophyll (HNLC) eastern equatorial Pacific Ocean (0°N, 95.5°W) during the EqPOS cruise in 2012. The particulate phosphorus and iron were enriched by factors of 72 and 11, respectively, in the SML samples in comparison with subsurface water (SSW) samples. Individual particle chemical analysis by SEM/EDX also showed higher phosphorus levels in most of the analyzed SML particles than in the SSW particles. These observations demonstrated a distinct biogeochemical enhancement in the SML in response to an external perturbation, most likely iron depositions into the HNLC ocean SML.