Estimating primary productivity of marine macroalgae in East Antarctica usingin situfluorometry

Abstract

Photosynthetic activity of marine macroalgae in the Windmill Islands, East Antarctica, was measured in situ using submersible modulated fluorometers. An empirical relation incorporating terms for respiration and non-linear electron transport was derived from simultaneous in vivo measurements of effective quantum yield ( PSII 0 ) and oxygen evolution. This relation was used with in situ measurements of PSII 0 and photosynthetic photon flux density acquired over 24-h periods to estimate oxygen evolution rates of algae over the course of the measurement period. Productivity ranged from À8 to 19 mmol O 2 g À1 FW h À1(FW ¼ fresh weight), with daily carbon gain ranging from À1.5 to 3.6 mg C g À1 FW d À1 for midnight ice-covered algae and midday ice-free algae, respectively. These values were similar to published values of productivity of Antarctic species derived from oxygen-and carbon-based techniques. The technique described here provides a simple and rapid means of estimating primary productivity in marine systems.

Benthic Biodiversity, Carbon Storage and the Potential for Increasing Negative Feedbacks on Climate Change in Shallow Waters of the Antarctic Peninsula

“…Approximately four times the standing stock of global kelp forests is exported [ 39 ] and so these values were multiplied by 5 (=1 × stock + 4 × export). Productivity, in terms of net carbon fixation, was calculated using the values from Antarctic macroalgae summarised in Runcie and Riddle [ 40 ]; values of 2 g C.kg wet mass −1 h −1 were used to calculate the annual productivity of this mass of macroalgae. Between 2 and 9% of macroalgal carbon is typically sequestered into sediments [ 41 , 42 ] and so an average value of 6% was used to calculate the proportion of carbon likely sequestered from macroalgal productivity.…”

ANTIOXIDANT AND ANTI-INFLAMMATORY ACTIVITIES FROM ETHANOL EXTRACT OF Eucheuma cottonii FROM LEMUKUTAN ISLAND WATERS WEST KALIMANTAN

“…Macroalgae is one of the photosynthetic organisms, found abundantly in marine waters (Setyobudiandi et al, 2009;Simatupang et al, 2018), and plays a crucial role in the primary productivity (Tait and Schiel, 2010;Runcie and Riddle, 2012;Sudhakar et al, 2018). In marine ecosystem, macroalgae act as an excellent natural resources due to their bioactive potential with diverse applications in various fields (Leandro et al, 2020), such as human health and alternative source of nutrients (Afonso et al, 2019;Corsetto et al, 2020;Kulshreshtha et al, 2020;Garcia-Oliveira et al, 2021;Carpena et al, 2021), medicine (Pooja, 2014), therapeutic (Ismail et al, 2020), cosmeceutical andnutraceutical (Garcia-Vaquero et al, 2020;Ruslan et al, 2021), therapeutic and pharmaceutical (Abdelwahab, 2017).…”

Development ofIn SituSensors for Chlorophyll Concentration Measurement

“…Fluorometry has long been used to study phytoplankton in natural aquatic environments. Typical applications include estimation of primary productivity [1][2][3] and phytoplankton distribution [4][5][6], understanding photosynthetic characteristics [7][8][9][10][11] and taxonomic discrimination [12,13], and assessment of nutrient status [14][15][16] and toxins sensitivity [17][18][19]. Due to the unique fluorescent properties of chlorophyll (Chl) and accessory phycobiliprotein (PBP) pigments contained within phytoplankton cells, the fluorometer is regarded as a highly sensitive tool for the quantification and analysis of phytoplankton [20].…”