RV POSEIDON Cruise Report POS420 COWACSS Biological observation and sampling of cold-water corals to investigate impacts on climate change

Trondheim – (Kristiansund) – Kiel 08. – (25.) – 30.09.201

Temperate carbonate cycling and water mass properties from intertidal to bathyal depths (Azores)

The rugged submarine topography of the Azores supports a diverse heterozoan association resulting in intense biotically-controlled carbonate-production and accumulation. In order to characterise this cold-water (C) factory a 2-year experiment was carried out in the southern Faial Channel to study the biodiversity of hardground communities and for budgeting carbonate production and degradation along a bathymetrical transect from the intertidal to bathyal 500 m depth. Seasonal temperatures peak in September (above a thermocline) and bottom in March (stratification diminishes) with a decrease in amplitude and absolute values with depth, and tidal-driven short-term fluctuations. Measured seawater stable isotope ratios and levels of dissolved nutrients decrease with depth, as do the calcium carbonate saturation states. The photosynthetic active radiation shows a base of the euphotic zone in ~70 m and a dysphotic limit in ~150 m depth. Bioerosion, being primarily a function of light availability for phototrophic endoliths and grazers feeding upon them, is ~10 times stronger on the illuminated upside versus the shaded underside of substrates in the photic zone, with maximum rates in the intertidal (−631 g/m2/yr). Rates rapidly decline towards deeper waters where bioerosion and carbonate accretion are slow and epibenthic/endolithic communities take years to mature. Accretion rates are highest in the lower euphotic zone (955 g/m2/yr), where the substrate is less prone to hydrodynamic force. Highest rates are found – inversely to bioerosion – on down-facing substrates, suggesting that bioerosion may be a key factor governing the preferential settlement and growth of calcareous epilithobionts on down-facing substrates. In context of a latitudinal gradient, the Azores carbonate cycling rates plot between known values from the cold-temperate Swedish Kosterfjord and the tropical Bahamas, with a total range of two orders in magnitude. Carbonate budget calculations for the bathymetrical transect yield a mean 266.9 kg of epilithic carbonate production, −54.6 kg of bioerosion, and 212.3 kg of annual net carbonate production per metre of coastline in the Azores C factory

Effects of ocean acidification and global warming on reef bioerosion—lessons from a clionaid sponge

Coral reefs are under threat, exerted by a number of interacting effects inherent to the present climate change, including ocean acidification and global warming. Bioerosion drives reef degradation by recycling carbonate skeletal material and is an important but understudied factor in this context. Twelve different combinations of pCO2 and temperature were applied to elucidate the consequences of ocean acidification and global warming on the physiological response and bioerosion rates of the zooxanthellate sponge Cliona orientalis—one of the most abundant and effective bioeroders on the Great Barrier Reef, Australia. Our results confirm a significant amplification of the sponges’ bioerosion capacity with increasing pCO2, which is expressed by more carbonate being chemically dissolved by etching. The health of the sponges and their photosymbionts was not affected by changes in pCO2, in contrast to temperature, which had significant negative impacts at higher levels. However, we could not conclusively explain the relationship between temperature and bioerosion rates, which were slightly reduced at both colder as well as warmer temperatures than ambient. The present findings on the effects of ocean acidification on chemical bioerosion, however, will have significant implications for predicting future reef carbonate budgets, as sponges often contribute the lion’s share of internal bioerosion on coral reefs

The impact of ocean acidification on the functional morphology of foraminifera

This work was supported by the NERC UK Ocean Acidification Research Programme grant NE/H017445/1. WENA acknowledges NERC support (NE/G018502/1). DMP received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Culturing experiments were performed on sediment samples from the Ythan Estuary, N. E. Scotland, to assess the impacts of ocean acidification on test surface ornamentation in the benthic foraminifer Haynesina germanica. Specimens were cultured for 36 weeks at either 380, 750 or 1000 ppm atmospheric CO2. Analysis of the test surface using SEM imaging reveals sensitivity of functionally important ornamentation associated with feeding to changing seawater CO2 levels. Specimens incubated at high CO2 levels displayed evidence of shell dissolution, a significant reduction and deformation of ornamentation. It is clear that these calcifying organisms are likely to be vulnerable to ocean acidification. A reduction in functionally important ornamentation could lead to a reduction in feeding efficiency with consequent impacts on this organism’s survival and fitness.Publisher PDFPeer reviewe

RV POSEIDON Cruise Report POS473 LORELEI II: LOphelia REef Lander Expedition and Investigation II, Tromsø – Bergen – Esbjerg, 15.08. – 31.08. – 04.09.2014

As a result of the raising CO2-emissions and the resultant ocean acidification (decreasing pH and carbonate ion concentration), the impact on marine organism that build their skeletons and protective shells with calcium carbonate (e.g., mollusks, sea urchins, coccolithophorids, and stony corals) becomes more and more detrimental. In the last few years, many experiments with tropical reef building corals have shown, that a lowering of the carbonate ion concentration significantly reduces calcification rates and therefore growth (e.g., Gattuso et al. 1999; Langdon et al. 2000, 2003; Marubini et al. 2001, 2002). In the middle of this century, many tropical coral reefs may well erode faster than they can rebuild. Cold-water corals are living in an environment (high geographical latitude, cold and deep waters) already close to a critical carbonate ion concentration below calcium carbonate dissolves. Actual projections indicate that about 70% of the currently known Lophelia reef structures will be in serious danger until the end of the century (Guinotte et al. 2006). Therefore L. pertusa was cultured at GEOMAR to determine its long-term response to ocean acidification. Our work has revealed that – unexpectedly and controversially to the majority of warm-water corals – this species is potentially able to cope with elevated concentrations of CO2. Whereas short-term (1 week) high CO2 exposure resulted in a decline of calcification by 26-29 % for a pH decrease of 0.1 units and net dissolution of calcium carbonate, L. pertusa was capable to acclimate to acidified conditions in long-term (6 months) incubations, leading to slightly enhanced rates of calcification (Form & Riebesell, 2012). But all these studies were carried out in the laboratory under controlled conditions without considering natural variability and ecosystem interactions with the associated fauna. Moreover, only very little is known about the nutrition (food sources and quantity) of cold-water corals in their natural habitat. In a multifactorial laboratory study during BIOACID phase II we could show that food availability is one of the key drivers that promote the capability of these organisms to withstand environmental pressures such as alterations in the carbonate chemistry and temperature (Büscher, Form & Riebesell, in prep.). To take into account the influences of natural fluctuations and interactions (e.g. bioerosion), we aim to merge in-situ results from the two research cruises POS455 and POS473 with laboratory experimental studies for a comprehensive understanding of likely ecosystem responses under past, present and future environmental conditions

Ward Identities, B-> \rho Form Factors and |V_ub|

The exclusive FCNC beauty semileptonic decay B-> \rho is studied using Ward identities in a general vector meson dominance framework, predicting vector meson couplings involved. The long distance contributions are discussed which results to obtain form factors and |V_ub|. A detailed comparison is given with other approaches.Comment: 30 pages+four postscript figures, an Appendix adde

Acclimatization of the crustose coralline alga Porolithon onkodes to variable pCO2

Ocean acidification (OA) has important implications for the persistence of coral reef ecosystems, due to potentially negative effects on biomineralization. Many coral reefs are dynamic with respect to carbonate chemistry, and experience fluctuations in pCO2 that exceed OA projections for the near future. To understand the influence of dynamic pCO2 on an important reef calcifier, we tested the response of the crustose coralline alga Porolithon onkodes to oscillating pCO2. Individuals were exposed to ambient (400 ??atm), high (660 ??atm), or variable pCO2 (oscillating between 400/660 ??atm) treatments for 14 days. To explore the potential for coralline acclimatization, we collected individuals from low and high pCO2 variability sites (upstream and downstream respectively) on a back reef characterized by unidirectional water flow in Moorea, French Polynesia. We quantified the effects of treatment on algal calcification by measuring the change in buoyant weight, and on algal metabolism by conducting sealed incubations to measure rates of photosynthesis and respiration. Net photosynthesis was higher in the ambient treatment than the variable treatment, regardless of habitat origin, and there was no effect on respiration or gross photosynthesis. Exposure to high pCO2 decreased P. onkodes calcification by >70%, regardless of the original habitat. In the variable treatment, corallines from the high variability habitat calcified 42% more than corallines from the low variability habitat. The significance of the original habitat for the coralline calcification response to variable, high pCO2 indicates that individuals existing in dynamic pCO2 habitats may be acclimatized to OA within the scope of in situ variability. These results highlight the importance of accounting for natural pCO2 variability in OA manipulations, and provide insight into the potential for plasticity in habitat and species-specific responses to changing ocean chemistry.Funding was provided by grants from the National Science Foundation (OCE-0417412, OCE-10-26852, OCE-1041270) and gifts from the Gordon and Betty Moore Foundation. The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

The sensorium at work: the sensory phenomenology of the working body

The sociology of the body and the sociology of work and occupations have both neglected to some extent the study of the ‘working body’ in paid employment, particularly with regard to empirical research into the sensory aspects of working practices. This gap is perhaps surprising given how strongly the sensory dimension features in much of working life. This article is very much a first step in calling for a more phenomenological, embodied and ‘fleshy’ perspective on the body in employment, and examines some of the theoretical and conceptual resources available to researchers wishing to focus on the lived working-body experiences of the sensorium. We also consider some possible representational forms for a more evocative, phenomenologically-inspired portrayal of sensory, lived-working-body experiences, and offer suggestions for future avenues of research

Doping Carbon Nanotube Ethylene-Vinyl Acetate Thin Films for Touch-Sensitive Applications

Transparent conductive films are key components of many optoelectronic devices but are often made from either scarce or brittle materials like indium tin oxide. Carbon nanotube-polymer films offer an abundant and flexible alternative. Here, we report how the dimensions of the carbon nanotube raw material affect their thin film performance and thickness yield when processed with the polymer ethylene-vinyl acetate. We perform chemical doping with several halogenated metals and find the electron affinity of the metal to be a good indicator of p-doping effectiveness. We identify CuCl2 as low-cost alternative to the established gold chloride dopants. Optimising the dopant deposition method allows us to reduce the effect of doping on the optical transmittance. Percolation analysis of our films demonstrates that optimized single-walled carbon nanotube-ethylene-vinyl acetate films show no sign of percolation effects down to thicknesses of 5 nm. Finally, we produce transparent touch-sensitive devices. Comparing several of these devices, we find a linear relationship between the sheet resistance and the on/off ratio of the touch sensing that can be used to determine a threshold film thickness. Using doped carbon nanotube-ethylene-vinyl acetate films increases the on/off ratio and allows us to fabricate touch-sensitive devices with an on/off ratio of 10 at 95% optical transmittance. This clearly demonstrates the potential of these films for transparent touch-sensitive applications

Sponge bioerosion accelerated by ocean acidification across species and latitudes?

In many marine biogeographic realms, bioeroding sponges dominate the internal bioerosion of calcareous substrates such as mollusc beds and coral reef framework. They biochemically dissolve part of the carbonate and liberate so-called sponge chips, a process that is expected to be facilitated and accelerated in a more acidic environment inherent to the present global change. The bioerosion capacity of the demosponge Cliona celata Grant, 1826 in subfossil oyster shells was assessed via alkalinity anomaly technique based on 4 days of experimental exposure to three different levels of carbon dioxide partial pressure (pCO(2)) at ambient temperature in the cold-temperate waters of Helgoland Island, North Sea. The rate of chemical bioerosion at present-day pCO(2) was quantified with 0.08-0.1 kg m(-2) year(-1). Chemical bioerosion was positively correlated with increasing pCO(2), with rates more than doubling at carbon dioxide levels predicted for the end of the twenty-first century, clearly confirming that C. celata bioerosion can be expected to be enhanced with progressing ocean acidification (OA). Together with previously published experimental evidence, the present results suggest that OA accelerates sponge bioerosion (1) across latitudes and biogeographic areas, (2) independent of sponge growth form, and (3) for species with or without photosymbionts alike. A general increase in sponge bioerosion with advancing OA can be expected to have a significant impact on global carbonate (re)cycling and may result in widespread negative effects, e.g. on the stability of wild and farmed shellfish populations, as well as calcareous framework builders in tropical and cold-water coral reef ecosystems