35 research outputs found
OPENMODS 2.0 “Instrument Jamming Meeting” report
Major achievements
The feedback provided by potential users on their needs was very much appreciated. They
underlined the importance of having:
● an easy to deploy instrument (i.e.: from small fishing boats);
● multi-parameter sensors in ONE device;
● less maintenance effort
and prioritized the variables to measure.
Although, there are technical limitations and different solutions and there is no one tool that
can do everything, which is low cost, has high resolution and low maintenance, the
outcomes of the platforms/sensors/communications working group meet the main
requirements that emerged.
Priority was given to:
● a platform that will operate in drifter mode which is extremely easy to deploy and
perfect for studies associated with search and rescue operations (another need that
has emerged). It also constantly guarantees the knowledge of the instrument position.
The platform can be easily converted into the moored mode.
● temperature and pressure sensors. The sensors will be low -cost with the idea to
replace them rather than calibrate them;
● LoRaWAN communications preferably with Bluetooth integration for the in-situ
download of the data
Challenges for global ocean observation: the need for increased human capacity
Sustained global ocean observations are needed to recognise, understand, and manage changes in marine biodiversity, resources and habitats, and to implement wise conservation and sustainable development strategies. To meet this need, the Global Ocean Observing System (GOOS), a network of observing systems distributed around the world and coordinated by the Intergovernmental Oceanographic Commission (IOC) has proposed Essential Ocean Variables (EOVs) that are relevant to both the scientific and the broader community, including resource managers. Building a network that is truly global requires expanding participation beyond scientists from well-resourced countries to a far broader representation of the global community. New approaches are required to provide appropriate training, and resources and technology should follow to enable the application of this training to engage meaningfully in global observing networks and in the use of the data. Investments in technical capacity fulfil international reporting obligations under the UN Sustainable Development Goal 14A. Important opportunities are emerging now for countries to develop research partnerships with the IOC and GOOS to address these obligations. Implementing these partnerships requires new funding models and initiatives that support a sustained research capacity and marine technology transfer
SRT-Joy – computer-assisted self-regulation training for obese children and adolescents: study protocol for a randomized controlled trial
Predicting Weight Outcomes in Preadolescence: The Role of Toddlers? Self-regulation Skills and the Temperament Dimension of Pleasure
Objective To investigate the role of toddlers? self-regulation skills and temperament in predicting weight outcomes in preadolescence. Method Participants for this study included 195 children (114 girls) obtained from three different cohorts participating in a larger ongoing longitudinal study. At 2 years of age, participants participated in several laboratory tasks designed to assess their self-regulation abilities, including emotion regulation, sustained attention, and delay of gratification, while parents filled out a temperament questionnaire to assess toddlers? pleasure expression. Height and weight measures were collected when children were 4, 5, 7, and 10 years of age. Children also filled out a body image and eating questionnaire at the 10 year visit. Results Self-regulation skills in toddlers were associated with both BMI development, pediatric obesity, and body image/eating concerns. The temperament dimension of pleasure was also associated with BMI development and pediatric obesity but not body image/eating concerns. Conclusion Self-regulation difficulties across domains as well as temperament based pleasure in toddlers represented significant individual risk factors for the development of pediatric obesity eight years later. Early self-regulation difficulties also contributed to body image and eating concerns that typically accompanied overweight children. The mechanisms by which early self-regulation skills and temperament based pleasure may contribute to the development of pediatric obesity and associated weight concerns are discussed
The role of nutrients in regulation and promotion of harmful algal blooms in upwelling systems
Phytoplankton productivity and community structure in the vicinity of the Crozet Plateau during austral summer 2004/2005
The CROZet natural iron bloom and EXport experiment (CROZEX) was carried out around the Crozet Plateau (Southern Ocean) in late austral spring-early summer 2004/2005. The primary aim of this study was to test the hypothesis that natural Fe fertilisation from the islands enhanced primary production to the north of the plateau, leading to elevated carbon export. During the 12-week shipboard study (November–January), size-fractionated chlorophyll-a (chl-a), primary productivity and phytoplankton pigments were determined at 20 stations around the Crozet Plateau, both inside and outside the expected bloom region. Satellite-derived chl-a data from August 2004 to April 2005 revealed that the cruise period covered the declining stage of a large phytoplankton bloom north of the Crozet Plateau. Productivity derived from satellite chl-a data showed a strong north–south gradient, with productivity reaching a maximum of 1.9 g C m?2 d?1 in the north (late October), 0.6 over the plateau (late March) and 0.4 in the south (early December). From November to early December, measured chl-a and productivity were still relatively high northwest of the plateau (54–74 mg chl-a m?2 and 0.5–1.1 g C m?2 d?1), the assemblage being dominated by Phaeocystis sp. and microplankton representing 50% of total chl-a. Declining biomass and productivity to the northwest in mid-December was associated with a picoplankton (52%) dominated community (19–38 mg chl-a m?2 and 0.1–0.4 g C m?2 d?1). In contrast, at the north eastern edge of the plateau, a mixed diatom/Phaeocystis dominated bloom (229 mg chl-a m?2 and 3 g C m?2 d?1) developed in mid-January. South of the plateau in the control high-nutrient low-chlorophyll (HNLC) region, biomass and productivity were always significantly lower, with only a small chl-a peak in December, and a community composed of microflagellates, cyanobacteria and some giant diatoms. Particulate organic carbon (POC):chl-a ratios provided physiological evidence for the impact of Fe fertilisation north of the plateau. The assimilation rate (i.e. integrated productivity normalised to integrated chl-a, ?P/?chl-a) did not show significant differences between the north and south, probably due to the late sampling period relative to the bloom peak. Overall, measurements of primary productivity during CROZEX supported the hypothesis of enhanced biomass and production due to natural iron enrichment of the region north of the Crozet Plateau, while south of the plateau, low biomass and productivity resulted primarily from Fe limitation
Iron–light interactions during the CROZet natural iron bloom and EXport experiment (CROZEX): II—Taxonomic responses and elemental stoichiometry
The CROZet natural iron bloom and EXport experiment (CROZEX) investigated the annual phytoplankton bloom that occurs in the vicinity of the Crozet plateau in the Polar Frontal Zone (PFZ) of the Southern Ocean. Shipboard manipulation experiments designed to investigate potential responses of phytoplankton community structure and elemental stoichiometry to iron (Fe) and/or light perturbation are compared to in situ data collected during CROZEX. The outcome of individual experiments was strongly influenced by initial phytoplankton community structure. For example Fe amendment of high (>8 ?M) silicic acid waters resulted in a strong response by medium-sized diatoms, including Eucampia antarctica. In contrast Phaeocystis antarctica dominated the community response to increased Fe within an experiment initiated during the early declining stage of the bloom. Conversely, small diatoms responded more strongly to increased irradiance, while the population of very large diatoms remained relatively static. Consistent with experimental results, the intense natural blooms north of the Crozet plateau were observed to be dominated by either P. antarctica or medium-sized diatoms while small phytoplankton and large diatoms dominated lower-chlorophyll waters in the south. In situ data and results from experiments supported previous observations of lower nitrate to phosphate removal ratios for diatoms compared to P. antarctica. Experimental and in situ data also supported previous work showing that silicic acid to nitrate removal ratios can be reduced under conditions of enhanced Fe availability. Higher irradiance decreased this ratio still further. Interactions between Fe and light were thus likely to have contributed to the observed decoupling of the major element cycles between the intense bloom that occurs north of Crozet and more typical PFZ conditions to the South. Specifically, silicic acid became exhausted in both systems, with drawdown in the south potentially resulting from co-limitation of diatom growth by Fe and light. In contrast, increased Fe supply in the north enhanced nitrogen, phosphorous and carbon drawdown in ratios that were dependent on the community composition of the resultant bloom. <br/
Nitrogen nutrition in assemblages dominated by Pseudo-nitzschia spp., Alexandrium catenella and Dinophysis acuminata off the west coast of South Africa
A study was carried out in the southern Benguela upwelling system in 2006 and 2007 toestablish how the nutrient regime determines community succession and the selection of harmfulalgal bloom species. In March 2006, Pseudo-nitzschia spp. reached concentrations of 13 × 106 cells l–1,representing 80% of the total estimated phytoplankton biomass, while chlorophyll a (chl a) reached57 µg l–1. High rates of NO3– uptake (?NO3–, maximum 0.56 µmol N l–1 h–1) led to NO3– depletion(<0.1 µM). However, cell numbers remained high for several days, sustained by regenerated nitrogen,with ƒ-ratios dropping from 0.79 to 0.12. In March 2007, a bloom of Alexandrium catenella (4.5 ×105 cells l–1, 77% of the phytoplankton biomass) occurred, with surface chl a concentrations of 26 µgl–1. NO3– concentrations were high (10 to 17 µM), sustaining high ?NO3– (maximum 0.61 µmol N l–1 h–1)and ƒ-ratios up to 0.87. In April, Dinophysis acuminata reached 3.1 × 104 cells l–1 (91% phytoplanktonbiomass), with NO3– concentrations <0.5 µM and ƒ-ratios <0.1, indicative of regenerated production.Nutrient uptake kinetics showed that Pseudo-nitzschia spp. displayed the highest maximumspecific uptake rates (15.0 × 10–3 and 18.0 × 10–3 h–1 for NO3– and NH4+, respectively). D. acuminatadisplayed the highest affinity for NH4+, as shown by its higher ? (slope of the nutrient uptake vs. concentrationcurve) of 20.7 × 10–3, compared to 13.4 × 10–3 and 5.9 × 10–3 h–1 (µmol N l–1)–1 for Pseudonitzschiaspp. and A. catenella, respectively. D. acuminata was an affinity strategist, successful innitrogen-depleted waters, whereas both Pseudo-nitzschia spp. and A. catenella were velocity strategists,better adapted to utilising high NO3– concentrations during upwelling pulses
New production and the f ratio around the Crozet Plateau in austral summer 2004–2005 diagnosed from seasonal changes in inorganic nutrient levels
Recent mesoscale iron-fertilisation experiments suggest that iron may be an important micronutrient in HNLC regions but estimates of carbon export from such experiments are inconclusive. An alternative strategy to estimate export from such environments is to observe naturally productive ecosystems associated with topography. One such system is the Crozet islands and associated plateau (Crozet), at 46°S, 52°E. Each year a large bloom of phytoplankton occurs to the north of Crozet with a reduced bloom occurring to the south. We use nitrate data from the Crozet region collected during austral summer 2004–2005 to estimate new production (NP) via the Redfield ratio. Peak integrated values of up to 50 g C m−2 to the north of the plateau and up to 15 g C m−2 to the south are inferred. We estimate total integrated primary production (TP) using satellite techniques and calculate f for each station. Overall NP is linearly related to TP. However, f declines at very high levels of TP because nitrate usage ceases despite continuing PP and because nitrate levels increased from their postbloom low. This results either from a resupply of nitrate from beneath the thermocline due to mixing processes or to the mixed-layer ammonification and nitrification of accumulated organic nitrogen. We discount the first possibility because our estimates of the mixing flux of nitrate appear to be inadequate to cause the entire recovery in nitrate levels, and because any mixing flux of nitrate would likely be accompanied by a resupply of iron, which would induce NP to occur and erode the resupply of nitrate. Instead we consider the recycling of accumulated organic nitrogen to be a more likely explanation based on our observation of high organic nitrogen levels in the mixed layer north of Crozet during the cruise. The implications of this conclusion are that euphotic zone nitrification is a significant process, and that in this system new and export production are not equivalent. This recycling is sufficiently large that it reduces our estimate of NP north of the plateau to a level where it is equivalent to NP in the south. Whether a similar refertilisation of the mixed layer occurred in the south of the study region, which would be consistent with a meridional gradient in carbon export, is unknown due to the limited duration of the shipboard programme