DeepIso - A global open database of stable isotope ratios and elemental contents for deep-sea ecosystems.

Stable isotopes have been instrumental to many key-findings about deep-sea ecosystem functioning, particularly in chemosynthesis-based habitats (hydrothermal vents, cold seeps). However, constraining sampling logistics commonly limit the scope, extent, and therefore insights drawn from isotope-based deep-sea studies. Overall, much is left to discover about factors globally influencing food web structure in deep-sea ecosystems. In this context, it is crucial that all generated data are easily discoverable, available and reusable. DeepIso is a collaborative effort to produce a global compilation of stable isotope ratios and elemental contents in organisms from deep-sea ecosystems. In doing so, it aims to provide the deep-sea community with an open data analysis tool that can be used in the context of future ecological research, and to help deep-sea researchers to use stable isotope markers at their full efficiency. The database, accessible under CC-BY licence at https://doi.org/10.17882/76595, currently contains 18677 fully documented measurements. Archived parameters include δ13C (n = 4587), δ15N (n = 4388), δ34S (n = 951), %C (n = 2740), %N (n = 2741), %S (n = 752) and C/N ratio (n = 2518). Those measurements pertain to 4378 distinct samples belonging to 493 taxa, plus sediments, suspended particulate organic matter, plankton and detritus. Samples were taken between 1989 and 2018 in multiple environments (hydrothermal vents, cold seeps, cold water coral reefs, and other benthic or pelagic environments) and at depths ranging up to 5209 meters. To maximise the scope of the project, we are looking to integrate more data, either underlying published articles, from grey literature, or even unpublished. We’ll be happy to assist in data formatting and publication. If you are willing to contribute, or simply if you have feedback about the database, please get in touch via [email protected]

Building up DeepIso - A global open database of stable isotope ratios and elemental contents for deep-sea ecosystems.

Stable isotopes have been instrumental to many key-findings about deep-sea ecosystem functioning, particularly in chemosynthesis-based habitats (hydrothermal vents, cold seeps). However, constraining sampling logistics commonly limit the scope, extent, and therefore insights drawn from isotope-based deep-sea studies. Overall, much is left to discover about factors globally influencing food web structure in deep-sea ecosystems. In this context, it is crucial that all generated data are easily discoverable, available, and reusable. DeepIso is a collaborative effort to produce a global compilation of stable isotope ratios and elemental contents in organisms from deep-sea ecosystems. In doing so, it aims to provide the deep-sea community with an open data analysis tool that can be used in the context of future ecological research, and to help deep-sea researchers to use stable isotope markers at their full efficiency. The database, accessible under CC-BY licence at https://doi.org/10.17882/76595, currently contains 18677 fully documented measurements. Archived parameters include δ13C (n = 4587), δ15N (n = 4388), δ34S (n = 951), %C (n = 2740), %N (n = 2741), %S (n = 752) and C/N ratio (n = 2518). Those measurements pertain to 4378 distinct samples belonging to 493 taxa, plus sediments, suspended particulate organic matter, plankton and detritus. Samples were taken between 1989 and 2018 in multiple environments (hydrothermal vents, cold seeps, cold water coral reefs, and other benthic or pelagic environments) and at depths ranging up to 5209 meters. To maximise the scope of the project, we are looking to integrate more data, either underlying published articles, from grey literature, or even unpublished. We’ll be happy to assist in data formatting and publication. If you are willing to contribute, or simply if you have feedback about the database, please get in touch via [email protected]

Association of Gender with Clinical Expression, Quality of Life, Disability, and Depression and Anxiety in Patients with Systemic Sclerosis

OBJECTIVES: To assess the association of gender with clinical expression, health-related quality of life (HRQoL), disability, and self-reported symptoms of depression and anxiety in patients with systemic sclerosis (SSc). METHODS: SSc patients fulfilling the American College of Rheumatology and/or the Leroy and Medsger criteria were assessed for clinical symptoms, disability, HRQoL, self-reported symptoms of depression and anxiety by specific measurement scales. RESULTS: Overall, 381 SSc patients (62 males) were included. Mean age and disease duration at the time of evaluation were 55.9 (13.3) and 9.5 (7.8) years, respectively. One-hundred-and-forty-nine (40.4%) patients had diffuse cutaneous SSc (dcSSc). On bivariate analysis, differences were observed between males and females for clinical symptoms and self-reported symptoms of depression and anxiety, however without reaching statistical significance. Indeed, a trend was found for higher body mass index (BMI) (25.0 [4.1] vs 23.0 [4.5], p = 0.013), more frequent dcSSc, echocardiography systolic pulmonary artery pressure >35 mmHg and interstitial lung disease in males than females (54.8% vs 37.2%, p = 0.010; 24.2% vs 10.5%, p = 0.003; and 54.8% vs 41.2%, p = 0.048, respectively), whereas calcinosis and self-reported anxiety symptoms tended to be more frequent in females than males (36.0% vs 21.4%, p = 0.036, and 62.3% vs 43.5%, p = 0.006, respectively). On multivariate analysis, BMI, echocardiography PAP>35 mmHg, and anxiety were the variables most closely associated with gender. CONCLUSIONS: In SSc patients, male gender tends to be associated with diffuse disease and female gender with calcinosis and self-reported symptoms of anxiety. Disease-associated disability and HRQoL were similar in both groups

Specific niche requirements underpin multidecadal range edge stability, but may introduce barriers for climate change adaptation

Aim: To investigate some of the environmental variables underpinning the past and present distribution of an ecosystem engineer near its poleward range edge. Location: >500 locations spanning >7,400 km around Ireland. Methods: We collated past and present distribution records on a known climate change indicator, the reef-forming worm Sabellaria alveolata (Linnaeus, 1767) in a biogeographic boundary region over 182 years (1836–2018). This included repeat sampling of 60 locations in the cooler 1950s and again in the warmer 2000s and 2010s. Using species distribution modelling, we identified some of the environmental drivers that likely underpin S. alveolata distribution towards the leading edge of its biogeographical range in Ireland. Results: Through plotting 981 records of presence and absence, we revealed a discontinuous distribution with discretely bounded sub-populations, and edges that coincide with the locations of tidal fronts. Repeat surveys of 60 locations across three time periods showed evidence of population increases, declines, local extirpation and recolonization events within the range, but no evidence of extensions beyond the previously identified distribution limits, despite decades of warming. At a regional scale, populations were relatively stable through time, but local populations in the cold Irish Sea appear highly dynamic and vulnerable to local extirpation risk. Contemporary distribution data (2013–2018) computed with modelled environmental data identified specific niche requirements which can explain the many distribution gaps, namely wave height, tidal amplitude, stratification index, then substrate type. Main conclusions: In the face of climate warming, such specific niche requirements can create environmental barriers that may prevent species from extending beyond their leading edges. These boundaries may limit a species’ capacity to redistribute in response to global environmental change

Rôles des espèces ingénieurs dans la structure et le fonctionnement des habitats benthiques côtiers

Les espèces ingénieurs modifient et façonnent leur environnement. Elles jouent des rôles souvent clés dans la structure et le fonctionnement des habitats, notamment dans les environnements marins côtiers. A travers plusieurs modèles biologiques, choisis essentiellement parmi les espèces tubicoles, cette synthèse s’intéresse aux effets des espèces ingénieurs sur la biodiversité des habitats, mais également sur leur fonctionnement. Même s’il existe un consensus pour dire que la présence d’espèces ingénieurs augmente la richesse spécifique, les changements sur la faune associée sont souvent complexes. En modifiant les paramètres environnementaux, les espèces ingénieurs ont des effets marqués sur la composition même des assemblages d’espèces : tantôt elles génèrent des habitats qui facilitent l’implantation d’un large spectre d’espèces, tantôt elles créent des conditions extrêmes qui sélectionnent fortement les espèces associées. Les espèces ingénieurs marines sont souvent grégaires et particulièrement abondantes. Elles sont aussi souvent suspensivores, c'est-à-dire qu’elles s’alimentent à partir de la matière en suspension dans la colonne d’eau. Ainsi, elles affectent également le fonctionnement des écosystèmes qu’elles colonisent, en particulier les structures et les flux des réseaux trophiques. L’utilisation de marqueurs trophiques permet de montrer comment de fortes densités de suspensivores peuvent affecter les flux de matière organique dans les réseaux trophiques côtiers ainsi que les relations entre les espèces. La compétition trophique entre suspensivores est limitée par une grande variété de mécanismes de capture, de sélection et de transport des particules alimentaires. Plusieurs perspectives de développement de ces travaux portent sur des indices de diversité fonctionnelle des habitats structurés par ces espèces ingénieurs. Ces indices doivent servir à quantifier la gamme des changements des fonctions écologiques assurées par ces habitats, souvent soumis à des pressions globales ou localisées. Les traits biologiques des espèces et/ou les marqueurs trophiques (isotopes et acides gras) apparaissent comme des pistes intéressantes pour quantifier les niches fonctionnelles théoriques et réalisées par les assemblages d’espèces associées aux habitats structurés par les espèces ingénieurs

Écologie des formations récifales à Sabellaria alveolata (L.) (valeur fonctionnelle et patrimoniale)

S. alveolata est un polychète grégaire qui élabore des structures biogéniques dont l'extension soulève la question de leur intérêt en tant que modèle biologique et leur rôle fonctionnel au sein de l'écosystème qui les abrite. S. alveolata est une espèce ingénieur de l'écosystème ; les structures récifales offrent un habitat pour de nombreuses espèces. La faune associée aux récifs contraste nettement, par la diversité et l'originalité des assemblages faunistiques, avec celle des sédiments avoisinants. De plus, de par la surface que couvrent ces polychètes filtreurs, les récifs apparaissent comme des compétiteurs potentiels des espèces cultivées. L'impact de l'homme est clairement identifié dans cette étude et la dégradation alarmante de l'état de santé des récifs a été soulignée. Nous avons montré, à travers différents aspects de la dynamique récifale et de la biologie de l'espèce, en quoi ces structures méritaient que leur soit portée en urgence une attention toute particulièreSabellaria alveolata is a gregarious polychaete that builds exceptional formations in the bay of Mont-Saint-Michel. Thus, questions regarding their functional role and their interest as biological model are now asked. This species is an ecosystem engineer because their resulting structures offer habitat for numerous species. There's a deep contrast between the Macoma balthica community, widely distributed in the bay, and reef associated species assemblages, richer and more original. Assessments of water filtered at the bay scale have shown equivalent volumes for S. alveolata reefs and stocks of cultivated species. S. alveolata reefs are submitted to anthropogenic disturbances. With the aim of protection and management of this biological inheritance, we studied the larval loop of this species, which is of primary importance in maintenance and resilience abilities of the reef. The relationship between human impacts and the reefs dramatic health is clearly underlinedPARIS-Museum Hist.Naturelle (751052304) / SudocSudocFranceF

The stony road to understand isotopic enrichment and turnover rates: insight into the metabolic part

Trophic enrichment factors (TEF) are essential to properly and fruitfully explore stable isotope analysis in ecology. And so is the time window of food source integration, usually estimated with the turnover rates (lambda) of isotopic incorporation. On the road to provide ecologists with a general and reliable method to obtain TEF and turnover rates for diet reconstruction, isotopists start realizing that those two parameters are ultimately linked with the physiological state of organisms and that metabolic pathways are of primary importance to understand the large ranges in TEF values. In this study, we used a diet-switching experiment for seven small marine invertebrates. Changes in isotopic compositions were fitted to an exponential decay model to estimate TEF and. values. We then partitioned the growth and the catabolism components of the turnover rate and tested how these components are correlated to the TEF among species. Results showed a significant linear negative relationship between TEF and growth values for both C and N. This ultimately means that the increase in body mass over a time window can be used to estimate the TEF values for a given species

Isotopic diversity indices: how sensitive to food web structure?

Recently revisited, the concept of niche ecology has lead to the formalisation of functional and trophic niches using stable isotope ratios. Isotopic diversity indices (IDI) derived from a set of measures assessing the dispersion/distribution of points in the δ-space were recently suggested and increasingly used in the literature. However, three main critics emerge from the use of these IDI: 1) they fail to account for the isotopic sources overlap, 2) some indices are highly sensitive to the number of species and/or the presence of rare species, and 3) the lack of standardization prevents any spatial and temporal comparisons. Using simulations we investigated the ability of six commonly used IDI to discriminate among different trophic food web structures, with a focus on the first two critics. We tested the sensitivity of the IDI to five food web structures along a gradient of sources overlap, varying from two distinct food chains with differentiated sources to two superimposed food chains sharing two sources. For each of the food web structure we varied the number of species (from 10 to 100 species) and the type of species feeding behaviour (i.e. random or selective feeding). Values of IDI were generally larger in food webs with distinct basal sources and tended to decrease as the superimposition of the food chains increased. This was more pronounced when species displayed food preferences in comparison to food webs where species fed randomly on any prey. The number of species composing the food web also had strong effects on the metrics, including those that were supposedly less sensitive to small sample size. In all cases, computing IDI on food webs with low numbers of species always increases the uncertainty of the metrics. A threshold of ~20 species was detected above which several metrics can be safely used

Preface--Contributions to the 8th International Conference on Applications of Stable Isotope Techniques to Ecological Studies (ISOECOL), Brest, France, 20-24 August 2012.

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