Journal Article

Origins and characteristics of dissolved organic matter fueling harmful dinoflagellate blooms revealed by δ13C and d/l-Amino acid compositions

Han, Heejun, Son, Moonho, Kwon, Hyeong Kyu, Park, Tae Gyu, Kim, Guebuem, Park, Jihyun

2022

Overview

We measured the concentrations of dissolved inorganic and organic nutrients, dissolved organic carbon (DOC), total hydrolyzable amino acids (THAA), fluorescent dissolved organic matter (FDOM), phytoplankton pigments, and δ 13 C-DOC during the summer of 2019 in the harmful dinoflagellate bloom regions of the southern coast of Korea. In the harmful dinoflagellate bloom region, the concentrations of inorganic nitrogen were depleted, inhibiting the growth of diatoms, while the concentrations of dissolved organic components (nutrients, DOC, FDOM, and amino acids) which fuel dinoflagellates were unusually high. Thus, we attempted to investigate the origins and characteristics of DOM which fuels the harmful dinoflagellate blooms. The δ 13 C-DOC values (− 22.2‰ to − 18.2‰) indicate that the elevated DOC concentrations result from in-situ biological production rather than terrestrial inputs. The enantiomeric (D/L) ratios of THAA indicate that dissolved organic nitrogen was more labile in the early stage of harmful dinoflagellate bloom and became more refractory in the final stage. Our results suggest that the marine production of bioavailable DOM plays an important role in initiating and sustaining harmful dinoflagellate blooms.

• Publisher: Nature Publishing Group UK,Nature Publishing Group,Nature Portfolio
• Subject: 704/47 / 704/829/827 / Amino acids / Blooms (microorganisms) / Dinoflagellates / Dissolved organic carbon / Dissolved organic matter / Dissolved organic nitrogen / Humanities and Social Sciences / Marine microorganisms / Microorganisms / multidisciplinary / Nitrogen / Nutrients / Organic nitrogen / Phytoplankton / Pigments / Science / Science (multidisciplinary)