Effects of the suspension feeding mussel Mytilus trossulus on a brackish water macroalgal and associated invertebrate community

The importance of suspension-feeding mussels is particularly apparent in benthic communities; however, the role of this feeding strategy on the development of macroalgal and associated invertebrate communities is in general poorly known. The effect of suspension-feeding mussels Mytilus trossulus on benthic communities was studied in an in situ factorial field experiment in the Northern Baltic Sea over one ice-free season. The experiment was performed under different regimes of wave exposure (low and moderate) and on different sedimentary habitats (soft bottom with high organic content, soft bottom with low organic content, and hard bottom). In general the presence of mussels was associated with increased biomass of filamentous algae, herbivores and deposit feeders and decreased biomass of charophytes. The effect of M. trossulus interacted with the effect of exposure and substrate. Stronger responses were observed in moderately exposed than in sheltered areas. The presence of M. trossulus affected charophytes and deposit feeders on sand with low content of organic matter and filamentous algae on pebbles but not on other substrate types. The magnitude of the effects varied between months. The results suggest that (i) even in dynamic coastal systems the biodeposits and excretions of mussels are at least partly assimilated locally and are not flushed away to the open sea, (ii) the accumulation of faecal material induced elevated growth of deposit feeders, (iii) mussels enhanced the growth of ephemeral macroalgae and reduced the growth of perennial macroalgae, and (iv) together with increasing benthic primary production, mussels indirectly increase the production of herbivores.     

Trait-based diversity of deep-sea benthic megafauna communities near the Deepwater Horizon oil spill site

Deep-sea ecosystems are fragile yet diverse habitats that are sensitive to disturbance. In the northern Gulf of Mexico deepwater extraction of hydrocarbons led to the accidental release of four million barrels of oil from the Macondo wellhead in 2010. The release of oil combined with the addition of dispersant at depth and the resulting delivery of oiled “marine snow” led to dramatic disruptions of diversity and ecosystem services within the near field deep-sea benthic communities. Analysis of the biological trait diversity of the surrounding megabenthos reveals notable loss of traits that may explain the stunted recovery of communities within 2 km of the wellhead. The present megafauna show complete loss of some traits relating to tier, motility, and feeding mechanisms. Functional evenness was higher than in surveyed unaffected sites, highlighting some loss of trait space, reflecting increasing abundances of scavengers and the loss of sessile invertebrates. Loss of biological traits that aid in ecosystem resilience has impeded recovery of benthic communities severely impacted by the Deepwater Horizon oil spill.     

Geochemistry and petrology of howardite Miller Range 11100: A lithologically diverse piece of the Vestan regolith

The howardite‐eucrite‐diogenite (HED) clan of meteorites, which most likely originate from the asteroid Vesta, provide an opportunity to combine in‐depth sample analysis with the comprehensive remote‐sensing data set from NASA's recent Dawn mission. Miller Range (MIL) 11100, an Antarctic howardite, contains diverse rock and mineral fragments from common HED lithologies (diogenites, cumulate eucrites, and basaltic eucrites). It also contains a rare pyroxferroite‐bearing lithology—not recognized in HED until recently—and rare Mg‐rich (Fo_86‐91) olivine crystals that possibly represent material excavated from the Vestan mantle. Clast components underwent different histories of thermal and impact metamorphism before being incorporated into this sample, reflecting the diversity in geological histories experienced by different parts of Vesta. The bulk chemical composition and petrography of MIL 11100 suggest that it is akin to the fragmental howardite meteorites. The strong lithological heterogeneity across this sample suggests that at least some parts of the Vestan regolith show heterogeneity on the mm‐scale. We combine the outcomes of this study with data from NASA's Dawn mission and hypothesize on possible source regions for this meteorite on the surface of Vesta.     

ESR isochron dating analyses at Bau de l'Aubesier,Provence, France: Clues to U uptake in fossil teeth

At Bau de l'Aubesier, Provence, Mousterian artifacts and human teeth occur in inhomogeneous (“lumpy”) sedimentary deposits that include bone and tooth fragments and extensive burnt horizons. Electron spin resonance (ESR) isochron analyses of mammal teeth, which use multiple subsamples with different U concentrations, can measure the external dose rate experienced by the tooth regardless of reworking and sedimentary dose rate changes. Isochron analyses do depend on the U uptake model assumed, but can also identify teeth that have experienced secondary U uptake or leaching. Using 11 teeth from six archaeological layers, the isochrons demonstrate that at least three teeth have experienced secondary uptake. For eight teeth, the U uptake has apparently not followed strictly early (EU), linear (LU), or recent uptake (RU), but more closely approximates LU‐RU. Comparing volumetrically averaged sedimentary geochemistry with thermoluminescent dosimetry suggests that fossil tissues in the sediment have also experienced LU‐RU uptake. LU‐RU uptake can explain standard ESR ages that underestimate the true fossil age. © 2001 John Wiley & Sons, Inc.     

Hybrid Neoliberalism: Implications for Sustainable Development

Neoliberalism is frequently blamed for challenges in achieving sustainable development; consequently some also question if sustainability is still a useful concept. Neoliberal influence on natural resource management has evolved over the last 30?years to a hybrid form that seeks to compensate for its negative social and environmental externalities. Through review of literature and critical analysis of three case studies of resource development in Australia and New Zealand, we argue that, in spite of modifications under hybrid approaches, neoliberalism still tests achievement of sustainability goals, due to privileging industry and shifting risk and costs to future generations, through inadequate regulation, neglect of public consultation, lack of transparency, and weak impact assessment. We suggest that while neoliberal approaches bring both benefits and disadvantages, sustainability principles must continue to be kept at the forefront of legislation, regulation and management.     

Development of a Default Vapor Intrusion Attenuation Factor for Industrial Buildings

An investigation at a major industrial facility in the Midwestern United States provides insights regarding the amount of attenuation of sub-surface vapors occurring at industrial buildings. The buildings at the facility were ranked in terms of vapor intrusion potential and testing began in October 2016 and is ongoing. Results have been evaluated for data collected at 718 unique locations across 77 buildings. A total of 1646 sample pairs (sub-slab and indoor air) have been collected and analyzed for 65 analytes, resulting in a total of 106,990 data pairs. As many as 49 sample pairs were collected within a given building during a single sampling event and up to 11 rounds of seasonal testing have been performed at selected buildings. Seasonal variability in sub-slab soil-gas concentrations was found to be negligible. Data analysis was performed to look for data trends across the entire data set and identify inter-building comparisons. This data evaluation focused on individual volatile organic compounds (e.g., tetrachloroethylene, trichloroethylene) present in the sub-slab soil gas at concentrations exceeding 1000 μg/m³. A total of 157 building-specific attenuation coefficients (α) were evaluated. This evaluation demonstrated that large industrial buildings have a much greater attenuation than that assumed for single-family residential buildings. All attenuation coefficient values were lower than 0.03, which is the standard regulatory default for non-residential buildings. The median value was 9.3E-05 and the 95% upper confidence limit was 2.7E-04. There is some evidence of lower attenuation under wintertime conditions. The data suggests that the default attenuation factor of 0.03 over-predicts indoor air impacts at this industrial facility by at least two orders of magnitude.