Understanding the hydrogeology and surface flow in the Cuatrocienegas Basin (NE Mexico) using stable isotopes

In this paper we present surface water oxygen (δ18O), hydrogen (δD) and inorganic carbon (δ13CDIC) isotope data to gain a better understanding of the modern day hydrogeology of Cuatrociénegas Basin, a semi-arid region in northeastern Mexico. Our study focuses on 26 water samples collected in March 2008 to investigate: 1) current provenance and flow pathways of surface waters, 2) the use of stable isotopes in identifying water loss and environmental degradation, and 3) human influence on hydrogeology. δ18O for Cuatrociénegas water samples ranged from −7.99 to +4.97‰ (mean −5.23 ± 3.13‰), δD from −54.8 to +0.3‰ (mean −42.4 ± 14.4‰), and δ13CTDICfrom −21.6 to −9.2‰ (mean −14.3 ± 3.4‰). Samples collected progressively away from their respective spring lines display increasing δ18O and δD values. Isotope data suggest that where the residence time of the groundwater is long and/or the system is hydrologically open, δ18O may not be a reliable indicator of water loss and environmental degradation. Our data suggest the central ciénega (area W(b)) is the most viable area for palaeoenvironmental study and long term monitoring is an essential tool in the identification of ecosystem damage and response, allowing for better future management of the complex and fragile CCB ecosystem

Have Centuries of Inefficient Fishing Sustained a Wild Oyster Fishery: a Case Study

The native European flat oyster (Ostrea edulis) has declined throughout its range, due to over-exploitation, a situation mirrored in oyster stocks globally. There are three remaining oyster fisheries in England (Fal, Solent, and Thames Estuary). The Fal oyster fishery though employs traditional methods, using hand-hauled dredges from rowing punts or under sail and is home to the last commercial sailing fleet in Europe. Against a backdrop of temporary closures to protect dwindling stocks in the Solent and Thames Estuary, this study considers whether the longevity of the Fal oyster fishery is linked to the traditional methods that have been employed for centuries. Using GPS tracking in combination with on board observers, we demonstrate that dredging under sail is inefficient compared to more modern mechanically powered methods that are utilised elsewhere. A review of historical landings suggests that both overall landings and fishing effort have declined. The fishery appears to have gone through cycles of over-exploitation and one closure due to disease. However, the key to the long-term survival of the Fal oyster fishery may be linked to the traditional method of dredging. It is estimated that a switch from traditional methods to modern techniques would result in a greater than 9 fold increase in effort per season. The data presented highlight this unique fishery as a counterfactual to the increases in power seen in commercial fisheries over the last century and serve as a reference point for future studies

"L'art poétique à l'usage du Petit Séminaire de Québec"

Y-a-t-il un « art poétique » surréaliste ? Si l'on en croit André Breton, non : lui se situe résolument du côté du « Manifeste », où l'art poétique se voit dénié sur ses deux versants - celui de l'artefact (techniques rhétoriques) et celui du poétique, engagé dans une « littérature » marquée ici du sceau de l'infamie. Le rationalisme éclate sous la pression d'une « raison élargie ». Simultanément, l'esprit du manifeste fait triompher les voies du désir : le « il y aura une fois » de « l'imagination ». D'où une téléologie de l'art, orienté vers sa « prophétie », et une épistémologie de sa réception, fondée sur l'éros. Ce qui suppose de ne pas glisser aux « techniques » qui mènent aux poncifs : d'où la Terreur.Is there a surrealist "poetic art" ? If we are to believe André Breton, the answer is No ; Breton for his part resolutely adheres to the "Manifesto". The possibility of a poetic art is denied both as art (rhetorical technique) and as poetry (a literary project here under the seal of infamy. The rationale of setting poetics in order collapses under the constraint of a "broader reason". At the same time, the spirit of the "Manifesto" marks the triumph of the ways of désire: the imperative "let there be" of the imagination. Hence there is a teleology of Art founded on "prophecy", and an epistemology of its réception based on Eros.The besetting danger is that "technique" (and consequently cliché) will predominate : hence the Terror

Vertical distribution and diurnal migration of atlantid heteropods

© Inter-Research 201 Understanding the vertical distribution and migratory behaviour of shelled holoplanktonic gastropods is essential in determining the environmental conditions to which they are exposed. This is increasingly important in understanding the effects of ocean acidification and climate change. Here we investigated the vertical distribution of atlantid heteropods by collating data from publications and collections and using the oxygen isotope (? 18 O) composition of single aragonitic shells. Data from publications and collections show 2 patterns of migration behaviour: small species that reside in shallow water at all times, and larger species that make diurnal migrations from the surface at night to deep waters during the daytime. The ? 18 O data show that all species analysed (n = 16) calcify their shells close to the deep chlorophyll maximum. This was within the upper 110 m of the ocean for 15 species, and down to 146 m for a single species. These findings confirm that many atlantid species are exposed to large environmental variations over a diurnal cycle and may already be well adapted to face ocean changes. However, all species analysed rely on aragonite supersaturated waters in the upper < 150 m of the ocean to produce their shells, a region that is projected to undergo the earliest and greatest changes in response to increased anthropogenic CO 2

Weakened magnetic braking as the origin of anomalously rapid rotation in old field stars

A knowledge of stellar ages is crucial for our understanding of many astrophysical phenomena, and yet ages can be difficult to determine. As they become older, stars lose mass and angular momentum, resulting in an observed slowdown in surface rotation. The technique of 'gyrochronology' uses the rotation period of a star to calculate its age. However, stars of known age must be used for calibration, and, until recently, the approach was untested for old stars (older than 1 gigayear, Gyr). Rotation periods are now known for stars in an open cluster of intermediate age (NGC 6819; 2.5 Gyr old), and for old field stars whose ages have been determined with asteroseismology. The data for the cluster agree with previous period-age relations, but these relations fail to describe the asteroseismic sample. Here we report stellar evolutionary modelling, and confirm the presence of unexpectedly rapid rotation in stars that are more evolved than the Sun. We demonstrate that models that incorporate dramatically weakened magnetic braking for old stars can---unlike existing models---reproduce both the asteroseismic and the cluster data. Our findings might suggest a fundamental change in the nature of ageing stellar dynamos, with the Sun being close to the critical transition to much weaker magnetized winds. This weakened braking limits the diagnostic power of gyrochronology for those stars that are more than halfway through their main-sequence lifetimes.Comment: 25 pages, 3 figures in main paper, 6 extended data figures, 1 table. Published in Nature, January 2016. Please see https://youtu.be/O6HzYgP5uyc for a video description of the resul

"Too Big To Ignore": A feasibility analysis of detecting fishing events in Gabonese small-scale fisheries.

This is the final version. Available from Public Library of Science via the DOI in this record. All shapefiles are available from the Dryad database (datadryad.org/stash/share/BN9V6JHrdep3pMWH7zGuUiOfK9IEaeeodQ9LzVOY1Cw).In many developing countries, small-scale fisheries provide employment and important food security for local populations. To support resource management, the description of the spatiotemporal extent of fisheries is necessary, but often poorly understood due to the diffuse nature of effort, operated from numerous small wooden vessels. Here, in Gabon, Central Africa, we applied Hidden Markov Models to detect fishing patterns in seven different fisheries (with different gears) from GPS data. Models were compared to information collected by on-board observers (7 trips) and, at a larger scale, to a visual interpretation method (99 trips). Models utilizing different sampling resolutions of GPS acquisition were also tested. Model prediction accuracy was high with GPS data sampling rates up to three minutes apart. The minor loss of accuracy linked to model classification is largely compensated by the savings in time required for analysis, especially in a context of nations or organizations with limited resources. This method could be applied to larger datasets at a national or international scale to identify and more adequately manage fishing effort.US Fish and Wildlife ServiceDepartment for Environment, Food and Rural Affairs UKLMI TAPIOCAEuropean UnionArc Emeraude Projec

Do female association preferences predict the likelihood of reproduction?

Sexual selection acting on male traits through female mate choice is commonly inferred from female association preferences in dichotomous mate choice experiments. However, there are surprisingly few empirical demonstrations that such association preferences predict the likelihood of females reproducing with a particular male. This information is essential to confirm association preferences as good predictors of mate choice. We used green swordtails (&lt;i&gt;Xiphophorus helleri&lt;/i&gt;) to test whether association preferences predict the likelihood of a female reproducing with a male. Females were tested for a preference for long- or short-sworded males in a standard dichotomous choice experiment and then allowed free access to either their preferred or non-preferred male. If females subsequently failed to produce fry, they were provided a second unfamiliar male with similar sword length to the first male. Females were more likely to reproduce with preferred than non-preferred males, but for those that reproduced, neither the status (preferred/non-preferred) nor the sword length (long/short) of the male had an effect on brood size or relative investment in growth by the female. There was no overall preference based on sword length in this study, but male sword length did affect likelihood of reproduction, with females more likely to reproduce with long- than short-sworded males (independent of preference for such males in earlier choice tests). These results suggest that female association preferences are good indicators of female mate choice but that ornament characteristics of the male are also important

Using Cumulative Impact Mapping to Prioritize Marine Conservation Efforts in Equatorial Guinea

This is the final version. Available on open access from Frontiers Media via the DOI in this recordData Availability Statement Ensemble ecological niche models (EENMs) and threat maps (anthropogenic footprint, cumulative impact, and cumulative utilization and impact) for each species (Atlantic humpback dolphin Sousa teuszii; bottlenose dolphin Tursiops truncatus; humpback whale Megaptera novaeangliae; leatherback Dermochelys coriacea; and olive ridley sea turtle Lepidochelys olivacea) are available from the Dryad Digital Repository doi: 10.5061/dryad.v6wwpzgr9 (Trew et al., 2019).Marine biodiversity is under extreme pressure from anthropogenic activity globally, leading to calls to protect at least 10% of the world’s oceans within marine protected areas (MPAs) and other effective area-based conservation measures. Fulfilling such commitments, however, requires a detailed understanding of the distribution of potentially detrimental human activities, and their predicted impacts. One such approach that is being increasingly used to strengthen our understanding of human impacts is cumulative impact mapping; as it can help identify economic sectors with the greatest potential impact on species and ecosystems in order to prioritize conservation management strategies, providing clear direction for intervention. In this paper, we present the first local cumulative utilization impact mapping exercise for the Bioko-Corisco-Continental area of Equatorial Guinea’s Exclusive Economic Zone – situated in the Gulf of Guinea, one of the most important and least studied marine regions in the Eastern Central Atlantic. This study examines the potential impact of ten direct anthropogenic activities on a suite of key marine megafauna species and reveals that the most suitable habitats for these species, located on the continental shelf, are subject to the highest threat scores. However, in some coastal areas, the persistence of highly suitable habitat subject to lower threat scores suggests that there are still several strategic areas that are less impacted by human activity that may be suitable sites for protected area expansion. Highlighting both the areas with potentially the highest impact, and those with lower impact levels, as well as particularly damaging activities can inform the direction of future conservation initiatives in the region.Waitt FoundationWildlife Conservation SocietyDarwin InitiativeDepartment for Environment, Food and Rural Affairs (Defra)Waterloo FoundationNatural Environment Research Council (NERC)Marine Turtle Conservation Fund (United States Fish and Wildlife Service, United States Department of the Interior)Vaalco EnergyHarvest Natural ResourcesSea World and Busch Gardens Conservation FundTullow OilOld Dominion UniversityWWFWildlife Conservation SocietyUniversity of Exete