A field deployable method for a rapid screening analysis of inorganic arsenic in seaweed

The authors thank the support for getting the seaweed samples from the projects funded under the Department of Agriculture, Food and the Marine’s Competitive research programmes in Ireland. Reference number 14 SF 860. The authors thank Corny Brombach for the graphical abstract.Peer reviewedPublisher PD

Arsenolipids are not uniformly distributed within two brown macroalgal species Saccharina latissima and Alaria esculenta

Open access via Springer Compact Agreement Acknowledgements Emeline Moreira is kindly thanked for her assistance with re-analysing a couple of samples for AsSugar measurement. Johannes Beere is thanked for the analysis on the Orbitrap for batch A. Urd Grandorf Bak is thanked for her helpful advice on seaweed. Funding information This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Skłodowska-Curie grant agreement no. 656596.Peer reviewedPublisher PD

Coastal iodine emissions: part 2. Chamber experiments of particle formation from Laminaria digitata-derived and laboratory-generated I2

Laboratory studies into particle formation from Laminaria digitata macroalgae were undertaken to elucidate aerosol formation for a range of I2 (0.3−76 ppbv) and O3(<3−96 ppbv) mixing ratios and light levels (EPAR = 15, 100,and 235 μmol photons m−2 s−1). No clear pattern was observed for I2 or aerosol parameters as a function of light levels. Aerosol mass fluxes and particle number concentrations,were, however, correlated with I2 mixing ratios for low O3mixing ratios of <3 ppbv (R2 = 0.7 and 0.83, respectively for low light levels, and R2 = 0.95 and 0.98, respectively for medium lightlevels). Additional experiments into particle production as a function of laboratory-generated I2, over a mixing ratio range of 1−8ppbv, were conducted under moderate O3 mixing ratios (∼24 ppbv) where a clear, 100-fold or greater, increase in the aeroso lnumber concentrations and mass fluxes was observed compared to the low O3 experiments. A linear relationship between particle concentration and I2 was found, in reasonable agreement with previous studies. Scaling the laboratory relationship to aerosol concentrations typical of the coastal boundary layer suggests a I2 mixing ratio range of 6−93 pptv can account for the observed particle production events. Aerosol number concentration produced from I2 is more than a factor of 10 higher than thatproduced from CH2I2 for the same mixing ratios

Coastal iodine emissions. 1. Release of I2 by Laminaria digitata in chamber experiments

Tidally exposed macroalgae emit large amounts of I2 and iodocarbons that produce hotspots of iodine chemistry and intense particle nucleation events in the coastal marine boundary layer. Current emission rates are poorly characterized, however,with reported emission rates varying by 3 orders of magnitude. In this study, I2 emissions from 25 Laminaria digitata samples were investigated in a simulation chamber using incoherent broadbandcavity-enhanced absorption spectroscopy (IBBCEAS). The chamber design allowed gradual extraction of seawater to simulate tidal emersion of algae. Samples were exposed to air with or without O3 and to varying irradiances. Emission of I2 occurred in four distinct stages: (1) moderate emissions from partially submerged samples;(2) a strong release by fully emerged samples; (3) slowing or stopping of I2 release; and (4) later pulses of I2 evident in some samples. Emission rates were highly variable and ranged from 7to 616 pmol min−1 gFW−1 in ozone-free air, with a median value of 55 pmol min−1 gFW−1 for 20 samples

Effects of high temperature and marine heat waves on seagrasses: Is warming affecting the nutritional value of Posidonia oceanica?

9 pages, 5 figures, 4 tables.-- Under a Creative Commons licensePrimary producers nutritional content affects the entire food web. Here, changes in nutritional value associated with temperature rise and the occurrence of marine heat waves (MHWs) were explored in the endemic Mediterranean seagrass Posidonia oceanica. The variability of fatty acids (FAs) composition and carbon (C) and nitrogen (N) content were examined during summer 2021 from five Mediterranean sites located at the same latitude but under different thermal environments. The results highlighted a decrease in unsaturated FAs and C/N ratio and an increase of monounsaturated FA (MUFA) and N content when a MHW occurred. By contrast, the leaf biochemical composition seems to be adapted to local water temperature since only few significant changes in MUFA were found and N and C/N had an opposite pattern compared to when a MHW occurs. The projected increase in temperature and frequency of MHW suggest future changes in the nutritional value and palatability of leavesThis research was financially supported by Botany and Plant Science at University of Galway, by the project Marine Habitats Restoration in a Climate Change-impaired Mediterranean Sea [MAHRES] funded by the Italian Ministry of Research under the PRIN 2017 Program (Project N. 2017MHHWBN; CUP: 74I19001320001), by “Fondo di Ateneo per la Ricerca 2019” by the University of Sassari, by PON - National Operational Programme - Research and Innovation 2014–2020, PhDs and research contracts on innovation-related topics and by the project DRESSAGE (MIS5045792) (through the Operational Program ‘Competitiveness, Entrepreneurship and Innovation’ (EPAnEK 2014–2020)Peer reviewe