A global satellite observation of phytoplankton taxonomic groups over the past two decades

Abstract

Marine phytoplankton are the primary producers of the oceanic biotic chain, crucial participants in the global carbon cycle, and important indicators of climate change, and have been a subject of great interest in many related research fields for a long time (Falkowski

Photophysiological Characterization of Phytoplankton by Measuring Pigment Production Rates: A Description of Detail Method and a Case Study

“…It is noteworthy that widely employed methods for phytoplankton pigment analysis using HPLC mainly involve the use of organic solvents [22][23][24][25][26], which could affect the carbon stable isotope values of photosynthetic pigments. Thus, a preliminary experiment was conducted to confirm the potential influence of these organic solvents on the delta 13 C value of the pigments prior to the in situ culture experiment for quantifying pigment production rates. Concurrently, an additional experiment was executed to examine the effect of varying sample injection volumes (100, 200, 300, 400, and 500 µL) on the carbon stable isotope values of the pigments.…”

“…Samples exceeding 13 L in volume were obtained. To determine the natural 13 C value of each pigment, a portion of the collected seawater samples underwent filtration (>4 L) using precombusted (450 • C) Whatman GF/F filter paper (47 mm). Prior to the incubation, the collected water samples were filtered through a 300 µm mesh to eliminate larger zooplankton and detritus.…”

“…Following filtration, the stable carbon isotope (NaH 13 CO 3 , 99%) was introduced as a tracer in accordance with established methodologies [17,21,27]. The quantity of 13 C introduced was maintained at 10-15% of the determined 13 C atoms derived from the total dissolved inorganic carbon within the water sample. The transparent polycarbonate carboys were incubated within a cooling-equipped polycarbonate incubator on deck.…”

“…In addition, studies on phytoplankton pigments are an important contribution to climate research. Monitoring changes in pigment concentrations provides important clues for phytoplankton responses to climate change and their role in carbon sequestration [6,[11][12][13]. In conclusion, pigment analysis provides valuable insights into the dynamics of aquatic environments, making them essential for both scientific understanding and practical applications.…”

“…The most appropriate tool to directly measure pigment synthesis by phytoplankton under natural light conditions is considered to be the 13 C tracer technique, which is widely applied to the primary production measurement of phytoplankton in various oceans [17,21]. However, the main bottlenecks for the precise pigment production analysis are pigment detectability via HPLC (high-performance liquid chromatography) analysis and the sensitivity of carbon stable isotope analysis from each pigment.…”