Coral recruitment and potential recovery of eutrophied and blast fishing impacted reefs in Spermonde Archipelago,Indonesia

Coral recruitment was assessed in highly diverse and economically important Spermonde Archipelago, a reef system subjected to land-based sources of siltation/pollution and destructive fishing, over a period of 2 years. Recruitment on settlement tiles reached up to 705 spat m⁻² yr⁻¹ and was strongest in the dry season (July–October), except off-shore, where larvae settled earlier. Pocilloporidae dominated near-shore, while a more diverse community of Acroporidae, Poritidae and others settled in the less polluted mid-shelf and off-shore reefs. Non-coral fouling community appeared to hardly influence initial coral settlement on the tiles, although, this does not necessarily infer low coral post-settlement mortality, which may be enhanced at the near- and off-shore reefs as indicated by increased abundances of potential space competitors on natural substrate. Blast fishing showed no local reduction in coral recruitment and live hard coral cover increased in oligotrophic reefs, indicating potential for coral recovery, if managed effectively.     

Probing the circumstellar structures of T Tauri stars and their relationship to those of Herbig stars

We present Hα spectropolarimetry observations of a sample of 10 bright T Tauri stars, supplemented with new Herbig Ae/Be star data. A change in the linear polarization across Hα is detected in most of the T Tauri (9/10) and Herbig Ae (9/11) objects, which we interpret in terms of a compact source of line photons that is scattered off a rotating accretion disc. We find consistency between the position angle (PA) of the polarization and those of imaged disc PAs from infrared and millimetre imaging and interferometry studies, probing much larger scales. For the Herbig Ae stars AB Aur, MWC 480 and CQ Tau, we find the polarization PA to be perpendicular to the imaged disc, which is expected for single scattering. On the other hand, the polarization PA aligns with the outer disc PA for the T Tauri stars DR Tau and SU Aur and FU Ori, conforming to the case of multiple scattering. This difference can be explained if the inner discs of Herbig Ae stars are optically thin, whilst those around our T Tauri stars and FU Ori are optically thick. Furthermore, we develop a novel technique that combines known inclination angles and our recent Monte Carlo models to constrain the inner rim sizes of SU Aur, GW Ori, AB Aur and CQ Tau. Finally, we consider the connection of the inner disc structure with the orientation of the magnetic field in the foreground interstellar medium: for FU Ori and DR Tau, we infer an alignment of the stellar axis and the larger magnetic field direction.     

Identification of data-driven Dutch dietary patterns that benefit the environment and are healthy

More sustainable dietary patterns are needed to mitigate global warming. This study aims to identify data-driven healthy dietary patterns that benefit the environment. In EPIC-NL, diet was assessed using a 178-item FFQ in 36,203 participants aged 20–70 years between 1993 and 1997. The Dutch Healthy Diet index 2015 (DHD15-index) was used to score healthiness of the diet. As proxy for environmental impact, greenhouse gas (GHG) emissions were calculated using life cycle analysis. To determine patterns that are both healthy and environmentally friendly, reduced rank regression was applied. A “Plant-based Pattern” characterized by high consumption of fruits, vegetables, and legumes, and low consumption of fries, red meat, and processed meat and a “Dairy-based Pattern” characterized by high consumption of dairy, and nuts and seeds and low consumption of coffee and tea, sugar-containing sodas, low-fiber bread, and savory sauces were derived. At equal energy intake, the diet of adherents (highest quartile) to the “Plant-based Pattern” were significantly healthier (89.8 points on the DHD15-index, p?<?0.0001) and more sustainable (3.96 kg C0₂-eq/day, p?<?0.0001) compared to the average diet (76.2 points, 4.06 kg C0₂-eq/day), whereas the “Dairy-based Pattern” was somewhat healthier (77.9 points, p?<?0.0001), but less sustainable (4.43 kg C0₂-eq/day, p?<?0.0001). When deriving dietary patterns based on health and environmental aspects of the diets, a “Plant-based” and a “Dairy-based” pattern were observed in our study population. Of these, the plant-based diet benefits health as well as the environment.     

The pre-glacial evolution of Wales

The classical explanation of the development of the Welsh landscape by the effects of a pulsed ‘eustatic’ uplift during the Cenozoic times is challenged by new data on the geology and geomorphology of Wales and the adjacent regions. The post-Caledonian surface developed over most of Wales in the upper Westphalian plays a major role in landform development. Since its emergence before mid-Cretaceous times, the Welsh Massif has suffered a long subaerial evolution which favoured a powerful chemical weathering. In Anglesey and St. David's Land, residual hills were formed by a process of differential weathering, and downwearing in saprolites. The Millstone Grit quartzites have been deeply weathered and dolines or flat-bottomed basins have been developed. From Cretaceous to Miocene times, a morphotectonic equilibrium has existed between uplift and denudation, so that, in the major part of Wales, the original planation surface was constantly maintained by lowering on itself and in some places it is possible to prove that no more than a few dozen metres of rock thickness disappeared during that period. Several main escarpments were produced by the warping of the planation surface along sharp flexures, during Neogene times. The Cenozoic vertical movements were controlled by the Caledonian or pre-Caledonian tectonic pattern which has divided the continental crust into major structural units. Welsh tectonic development is related to the opening of the North Atlantic, associated stresses reactivating ancient lines of weakness in the heterogeneous lower crust or upper mantle.     

Asteroseismology of Sun-like stars

Yvonne P Elsworth and Michael J Thompson examine the theory and practice of asteroseismology, the study of the oscillations of Sun-like stars.     

Pliocene sedimentation in a shallow, cool-water, estuarine gulf, Murray Basin, South Australia

The Pliocene Norwest Bend Formation is a well‐preserved succession of terrestrial and shallow‐marine deposits in the Murray Basin, South Australia. Sediments in this unit consist of two discrete terrigenous clastic‐rich, decametre‐scale sequences, or informal members, which record episodes of marine incursion during the Early and Late Pliocene respectively. The base of each sequence is a transgressive lag and/or strandline deposit that is transitional upwards into a highstand, subtidal, terrigenous clastic and cool‐water carbonate sediment accumulation. The top of each sequence is incised by fluvial channels that are filled by river deposits which formed as relative sea‐level fell and terrestrial environments prograded basinward. Sedimentological data suggest that gross stratigraphic architecture was primarily determined by glacioeustasy. Differences in sedimentary style between these two sequences, however, reflect a major climatic change that took place in southern Australia during the mid‐Pliocene. The lower quartzose sand member is formed of siliciclastic sediment derived from prolonged, deep, subaerial weathering and contains a bivalve‐dominated, cool‐temperate, open‐marine mollusc assemblage. These sediments accumulated under an equitable, relatively warm, humid climate. The Murray Basin during this time, because of high fluvial discharge, was a salt‐wedge estuary with typical estuarine circulation. In contrast, the upper, oyster‐rich member is typified by large monospecific oyster buildups that grew in restricted coastal environments. Strandline deposits contain a warm‐temperate skeletal assemblage. Contemporaneous aeolian sediments accumulated under warm, semi‐arid climatic conditions. Well‐developed ferricrete, silcrete and calcrete horizons reflect cyclic conditions of rainwater infiltration and evaporation in the seasonally dry climate that typifies southern Australia today. Highly seasonal rainfall produced an estuary that fluctuated annually from being well to partially mixed. These Pliocene sediments support the notion that mollusc‐rich facies are the signature of cool‐water carbonate accumulations in inboard neritic environments. Unlike bryozoans that dominate the outer parts of Cenozoic cool‐water carbonate shelves, molluscs evolved to exploit an array of coastal ecosystems with wide salinity variations and variable sedimentation rates.     

Holocene carbonate sedimentation on the west Eucla Shelf, Great Australian Bight: a shaved shelf

The southern continental margin of Australia is a cool-water carbonate sedimentary province located in a high-energy, swell-dominated oceanographic setting. A vibrocore transect of ¹⁴C-dated sediments across the centre of the Eucla Shelf is the first record of Holocene shelf deposition in the Great Australian Bight. Much of the seafloor shallower than 70 m water depth, the base of wave abrasion, is bare Cenozoic limestone, in some places encrusted by (?) Late Pleistocene, coral-rich, limestone that is cemented by high-magnesium calcite (12 mole% MgCO₃). The areally extensive, 100 km-wide, hard, bored substrate supports an epibiota of coralline algae, minor bryozoans and soft algae or is covered by patches of Holocene sediment up to 1.5 m thick; generally a basal bivalve lag (< 3 ka) overlain by quartzose-bioclastic palimpsest sand. This pattern of active carbonate production but little accretion on the wave-swept mid- to inner-shelf is similar to that on other parts of the southern Australian continental margin. The term shaved shelf is proposed for this style of carbonate platform, formed by alternating periods of sediment accretion, cementation and erosion.

The palimpsest sand is typically rich in bivalves, coralline algae and locally, detrital dolomite. Outer shelf Holocene sediment, below the base of wave abrasion but inboard of the shelf edge, is a metre-thick unit of fine, microbioclastic muddy sand with minor delicate bryozoans overlying a 9–13 ka rhodolith gravel. Some of this outer shelf sediment appears to have been resedimented. The shelf edge is a sandy and rocky seafloor with active bryozoan growth and sediment production.

The Holocene sediments are enriched in coralline algal particles and conspicuous large foraminifers (cf. Marginopora) and depleted in bryozoans, as compared to coeval deposits on the Lacepede and Otway shelves off southeastern Australia. These differences are interpreted to reflect warmer waters of the Leeuwin Current and prevalent downwelling in this area as opposed to the general upwelling and colder waters in the east.