Bryozoans are Major Modern Builders of South Atlantic Oddly Shaped Reefs

Supplementary information accompanies this paper at https://doi.org/10.1038/s41598-018-27961-6.In major modern reef regions, either in the Indo-Pacific or the Caribbean, scleractinian corals are described as the main reef framework builders, often associated with crustose coralline algae. We used underwater cores to investigate Late Holocene reef growth and characterise the main framework builders in the Abrolhos Shelf, the largest and richest modern tropical reef complex in the South Western Atlantic, a scientifically underexplored reef province. Rather than a typical coralgal reef, our results show a complex framework building system dominated by bryozoans. Bryozoans were major components in all cores and age intervals (2,000 yrs BP), accounting for up to 44% of the reef framework, while crustose coralline algae and coral accounted for less than 28 and 23%, respectively. Reef accretion rates varied from 2.7 to 0.9 mm yr−1, which are similar to typical coralgal reefs. Bryozoan functional groups encompassed 20 taxa and Celleporaria atlantica (Busk, 1884) dominated the framework at all cores. While the prevalent mesotrophic conditions may have driven suspensionfeeders’ dominance over photoautotrophs and mixotrophs, we propose that a combination of historical factors with the low storm-disturbance regime of the tropical South Atlantic also contributed to the region’s low diversity, and underlies the unique mushroom shape of the Abrolhos pinnacles.We thank CNPq/FAPES-Sisbiota/PELD, CAPES/IODP, CAPES/Ciências do Mar, and ANP/Brasoil for long term project funding. We also thank ICMBio for research permits and field logistic support, and Conservation International for providing and authorizing the use of the IKONOS image. JMW and JCB are International Visiting Researcher at UFES and JBRJ, supported by the Science Without Borders program. Zá Cajueiro provided invaluable field support and Ronaldo Francini, Carlos Janovitch and Lucio Engler helped in the drilling operations. This is a contribution from the Rede Abrolhos (abrolhos.org)

Rapid glaciation and a two-step sea-level plunge into The Last Glacial Maximum

The approximately 10,000-year-long Last Glacial Maximum, before the termination of the last ice age, was the coldest period in Earth’s recent climate history1. Relative to the Holocene epoch, atmospheric carbon dioxide was about 100 parts per million lower and tropical sea surface temperatures were about 3 to 5 degrees Celsius lower2,3. The Last Glacial Maximum began when global mean sea level (GMSL) abruptly dropped by about 40 metres around 31,000 years ago4 and was followed by about 10,000 years of rapid deglaciation into the Holocene1. The masses of the melting polar ice sheets and the change in ocean volume, and hence in GMSL, are primary constraints for climate models constructed to describe the transition between the Last Glacial Maximum and the Holocene, and future changes; but the rate, timing and magnitude of this transition remain uncertain. Here we show that sea level at the shelf edge of the Great Barrier Reef dropped by around 20 metres between 21,900 and 20,500 years ago, to −118 metres relative to the modern level. Our findings are based on recovered and radiometrically dated fossil corals and coralline algae assemblages, and represent relative sea level at the Great Barrier Reef, rather than GMSL. Subsequently, relative sea level rose at a rate of about 3.5 millimetres per year for around 4,000 years. The rise is consistent with the warming previously observed at 19,000 years ago1,5, but we now show that it occurred just after the 20-metre drop in relative sea level and the related increase in global ice volumes. The detailed structure of our record is robust because the Great Barrier Reef is remote from former ice sheets and tectonic activity. Relative sea level can be influenced by Earth’s response to regional changes in ice and water loadings and may differ greatly from GMSL. Consequently, we used glacio-isostatic models to derive GMSL, and find that the Last Glacial Maximum culminated 20,500 years ago in a GMSL low of about −125 to −130 metres.Financial support of this research was provided by the JSPS KAKENHI (grant numbers JP26247085, JP15KK0151, JP16H06309 and JP17H01168), the Australian Research Council (grant number DP1094001), ANZIC, NERC grant NE/H014136/1 and Institut Polytechnique de Bordeaux

Effect of fertilization with manure and organic wastes used in rye monoculture on the content of phenol compounds in the soil

Исследования касались влияния органических удобрений на общее содержание феноловых соединений в образцах почвы, взятых из-под монокультуры ржи до глубины 60 см. Их высокие дозы, введенные в почву в год заложения полевого опыта (1981), привели к увеличению концентрации фенолов в очередности: навоз < кератино-коро-карбамидный гранулят < осадок из коммунальных сточных вод. Значительно меньше фенолов накопилось в почвенной среде, главным образом, по применении 2 последних удобрений, в дозах, делимых по 1/3 полной в течение 3 лет. Концентрации феноловых соединений достигли своего максимума в пахотном слое почвы, минимума - в слое 20-40 см. Наиболее интенсивно перемещались до глубины 40-60 см фенолы, возникшие в почве из изменений осадка коммунальных сточных вод, слабее же всего - из кератино-коро-карбамидного гранулята.The authors studied the effect of organic fertilizers on the total content of phenol compounds in soil samples taken from rye monoculture down to a depth of 60 cm. Large doses of organic fertilizers introduced into the soil in the year the field experiment was set up (1981) brought an increase in phenols concentration, in the following sequence: manure < keratin-bark-urea granulate<municipal sewage sludge. Considerably less phenol accumulated in the soil environment, especially after the application of the two letter fertilizers, applied as 1/3rd of the full dose over a period of three years. Phenol compounds concentrations reached their maximum in the arable horizon of the soil, and a minimum in the 20-40 cm horizon. Transport down to the 40-60 cm horizon was the most intense in the case of phenols originating from sewage sludge decomposition, and the least - in the case of phenols from keratin-bark-urea granulate

Exploring coral reef responses to millennial-scale climatic forcings: insights from the 1-D numerical tool pyReef-Core v1.0

Assemblages of corals characterise specific reef biozones and the environmental conditions that change spatially across a reef and with depth. Drill cores through fossil reefs record the time and depth distribution of assemblages, which captures a partial history of the vertical growth response of reefs to changing palaeoenvironmental conditions. The effects of environmental factors on reef growth are well understood on ecological timescales but are poorly constrained at centennial to geological timescales. pyReef-Core is a stratigraphic forward model designed to solve the problem of unobservable environmental processes controlling vertical reef development by simulating the physical, biological and sedimentological processes that determine vertical assemblage changes in drill cores. It models the stratigraphic development of coral reefs at centennial to millennial timescales under environmental forcing conditions including accommodation (relative sea-level upward growth), oceanic variability (flow speed, nutrients, pH and temperature), sediment input and tectonics. It also simulates competitive coral assemblage interactions using the generalised Lotka–Volterra system of equations (GLVEs) and can be used to infer the influence of environmental conditions on the zonation and vertical accretion and stratigraphic succession of coral assemblages over decadal timescales and greater. The tool can quantitatively test carbonate platform development under the influence of ecological and environmental processes and efficiently interpret vertical growth and karstification patterns observed in drill cores. We provide two realistic case studies illustrating the basic capabilities of the model and use it to reconstruct (1) the Holocene history (from 8500 years to present) of coral community responses to environmental changes and (2) the evolution of an idealised coral reef core since the last interglacial (from 140 000 years to present) under the influence of sea-level change, subsidence and karstification. We find that the model reproduces the details of the formation of existing coral reef stratigraphic sequences both in terms of assemblages succession, accretion rates and depositional thicknesses. It can be applied to estimate the impact of changing environmental conditions on growth rates and patterns under many different settings and initial conditions

High-resolution hyperspectral imaging of diagenesis and clays in fossil coral reef material: a nondestructive tool for improving environmental and climate reconstructions

Hyperspectral imagery (1000–2500 nm) was used to quantitatively map carbonate and clay minerals in fossil reef cores that are relevant to accurately reconstructing past environmental and climatic conditions. Techniques were developed using hyperspectral imagery of fossil reef corals and cores acquired from three different geological settings, and were validated against independent measures of calcite to aragonite ratios. Aragonite, calcite, and dolomite were distinguished using a combination of the wavelength position and asymmetry of the primary carbonate absorption between 2300 and 2350 nm. Areas of core containing small amounts of calcite (>2–5%) were distinguished from aragonite in imagery of two cores, enabling quantitative maps of these minerals to be constructed. Dolomite was found to be the dominant mineral in another core. Trace amounts of the aluminium-rich clay mineral kaolinite were detected, quantified, and mapped in one core using its diagnostic absorption feature near 2200 nm. The amounts of clay detected from hyperspectral imagery were below the limits of detection by standard X-ray diffraction techniques but its presence was confirmed by Fourier Transform Infrared Spectroscopy. Hyperspectral imagery acquired at high spatial resolution simplifies vetting procedures for secondary carbonate minerals in coral reef cores, significantly reduces sampling time and costs, and is a powerful nondestructive tool to identify well-preserved coral aragonite in cores for uses in paleoclimate, paleoenvironment and paleoecosystem reconstruction

Enhancing mixed-matrix membrane performance with metal-organic framework additives

Published: June 12, 2017Metal–organic frameworks (MOFs), as porous fillers possessing molecular sieving properties, have been combined with polymers to give mixed-matrix membranes (MMMs) with enhanced separation performance. This field of research has produced a large number of different membranes, and many MOF/polymer combinations have been tested and reported to show potential application to industrial gas separation. Although MOFs have been proposed as novel additives with high porosity and tunable pore size, which were supposed to outperform other porous fillers, due to restrictions in separation performance of the filler and challenges concerning the compatibility of polymer and MOF, only a small fraction of these works report both improved permeability and selectivity. In this review these challenges are set into the context of MOF synthesis and membrane fabrication by the choice of appropriate polymer/MOF combinations, utilization of the MOF functional sites, modification of the MOF surface chemistry or pore texture and size, and also targeted influence of the size and shape of the filler particles. The effect of the highlighted MOF additives on the gas separation performance is analyzed and discussed by comparison of the gas permeability and selectivity. This emphasizes strategies by which high performing MMMs can be achieved through accessing the full potential of the porous MOF fillers.Janina Dechnik, Christopher J. Sumby, and Christoph Jania