Signification environnementale de guano de salanganes et de chiroptères de Nouvelle-Calédonie. Premiers résultats
L'intérêt est grandissant pour le potentiel présenté par les acccumulations cavernicoles de guano de chauves-souris et d'oiseaux en tant qu'enregistrements stratigraphiques continentaux, complémentaires voire alternatifs aux archives étudiées générale-ment (sédiments lacustres, palustres, tourbeux, etc.). Ces dépôts permettent des reconstructions de la variabilité climatique à haute résolution pour des échelles de temps récentes à plus anciennes, grâce à la calibration de nouveaux proxies susceptibles d'enregistrer ces variations. Ainsi la comparaison du contenu pollinique et des traceurs isotopiques δ13 C et δD des n-alcanes du guano de différents animaux insectivores, les salanganes diurnes (Collocalia spodiopygia) et les chiroptères nocturnes (Micropterus robustior) cohabitant dans de nombreuses grottes de Nouvelle-Calédonie, met en évidence une grande variabilité. Celle-ci est à l'image des cibles de nourrissage des proies appétées et de leur interaction avec les composantes de l'écosystème, en particulier les plantes. La grande richesse du contenu pollinique observée dans les deux types de guano, bien que présentant 50 % de taxons communs, souligne des aires de nourrissage préférentielles. Elle montre aussi des fluctuations interannuelles, marqueurs probables de changements environnementaux, sinon climatiques. Cet article présente des premiers résultats obtenus sur le sondage HAK1 prélévé dans un amas de guano de salanganes de la grotte Hama sur l'île de Lifou, l'une des îles Loyautés. La comparaison entre les données de géochimie isotopique moléculaire (isotopes du carbone δ13C et de l'hydrogène δD du n-alcane C29) et les données pluviométriques met en évidence une bonne covariation interprétée comme marqueur du signal climatique ENSO contemporain des dépôts de guano analysés. Ce travail préliminaire confirme le fort potentiel des amas de guano cavernicoles pour étudier à haute résolution les changements paléo-environnementaux.
(Quaternaire. vol. 28, n° 1142-2904, pp. 401-412, 22/10/2026)
BTP, LOCEAN, IPSL, ENS-PSL, UVSQ, UPMC, CEA, INSU - CNRS, X, CNES, CNRS, MNHN, IRD, UPMC, INSU - CNRS, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IAC
Identifying early modern human ecological niche expansions and associated cultural dynamics in the South African Middle Stone Age
The archaeological record shows that typically human culturaltraits emerged at different times, in different parts of the world,and among different hominin taxa. This suggests that their emer-gence is the outcome of complex and non-linear evolutionarytrajectories—influenced by environmental, demographic and so-cial factors—that need to be understood and traced at regionalscales. The application of predictive algorithms using archaeo-logical and paleoenvironmental data allows one to estimate theecological niches occupied by past human populations and iden-tify niche changes through time, thus providing the possibilityof investigating relationships between cultural innovations andpossible niche shifts. By using such methods to examine twokey southern Africa archaeological cultures, the Still Bay (76–71thousand years ago; ka) and the Howiesons Poort (66–59 ka), weidentify a niche shift characterized by a significant expansion in thebreadth of the Howiesons Poort ecological niche. This expansion iscoincident with aridification occurring across Marine Isotope Stage4 (ca. 72–60 ka) and especially pronounced at 60 ka. We arguethat this niche shift was made possible by the development ofa flexible technological system, reliant on composite tools andcultural transmission strategies based more on“product copying”rather than“process copying”. These results counter the one niche-one human taxon equation. They indicate that what makes ourcultures, and probably those of other members of our lineage,unique is their flexibility and ability to produce innovations thatallow a population to shift its ecological niche
(Proceedings of the National Academy of Sciences of the United States of America. vol. 114, n° 0027-8424, pp. 7869-7876, 22/10/2026)
PACEA, UB, CNRS, OIST, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, WITS, EPHE, PSL
Mission Baelo Claudia, Année 2017, Rapport d’activités
(22/10/2026)
LIENSs, INSU - CNRS, ULR, CNRS, HALMA, CNRS, MC, IRAA, UL2, AMU, CNRS, HeRMA [Poitiers], UP, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Equilibrium modeling of the Beach Profile on a Macrotidal Embayed Beach
Predicting the pluriannual variability of shoreline position in response to hydrodynamic forcing (waves and tides) is of primordial interest scientists, engineers, and beach managers. 11-year time series of monthly profile beach survey and hourly incident wave conditions are analyzed on a macrotidal sandy embayed beach in Brittany (France). An equilibrium model is applied to study the variation of the beach profile position over the whole intertidal zone as a function of the energy wave, wave power and water level. The predictive ability of the equilibrium model is around 60% in the upper intertidal zone but decreases with decreasing elevation in the lower intertidal zone. The predicted result on the lower part taking into account of the still water level is not improved, but the erosion and accretion parameters are more reliable, according to the physical processes and could be compared to other study sites.
(pp. pp. 760-771, 22/10/2026)
LGO, UBS, IFREMER, UBO EPE, CNRS, LHSV, ENPC, EDF [E.D.F.], Cerema Equipe-projet HA, Cerema, Cerema Equipe-projet HA, Cerema, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, CNRS, UB, LETG, UNICAEN, NU, UA, EPHE, PSL, UBO EPE, UR2, CNRS, IGARUN, UN
A DEB-IB model to test trophic and ontogenic triggers on the downstream migration of juvenile European sturgeon
Our objective was to integrate the fish physiology within a rigorous conceptual framework to coherently simulate the different biological processes constrained by possible environmental and anthropogenic pressures on individuals.
(pp. 1, 22/10/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Toward a phenological mismatch in estuarine pelagic food web?
Alterations of species phenology in response to climate change are now unquestionable. Until now, most studies have reported precocious occurrence of life cycle events as a major phenological response. Desynchronizations of biotic interactions, in particular predator-prey relationships, are however assumed to strongly impact ecosystems' functioning, as formalized by the Match-Mismatch Hypothesis (MMH). Temporal synchronicity between juvenile fish and zooplankton in estuaries is therefore of essential interest since estuaries are major nursery grounds for many commercial fish species. The Gironde estuary (SW France) has suffered significant alterations over the last three decades, including two Abrupt Ecosystem Shifts (AES), and three contrasted intershift periods. The main objective of this study was to depict modifications in fish and zooplankton phenology among inter-shift periods and discuss the potential effects of the resulting mismatches at a community scale. A flexible Bayesian method was used to estimate and compare yearly patterns of species abundance in the estuary among the three pre-defined periods. Results highlighted (1) an earlier peak of zooplankton production and entrance of fish species in the estuary and (2) a decrease in residence time of both groups in the estuary. Such species-specific phenological changes led to changes in temporal overlap between juvenile fish and their zooplanktonic prey. This situation questions the efficiency and potentially the viability of nursery function of the Gironde estuary, with potential implications for coastal marine fisheries of the Bay of Biscay.
(PLoS ONE. vol. 12, n° 1932-6203, pp. e0173752, 22/10/2026)
UR EABX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Is apparent low productivity of the invasive marine mollusc Crepidula fornicata Linnaeus, 1758 related to biased age determination?
The slipper limpet Crepidula fornicata Linnaeus, 1758 is a major exotic invader of East North Atlantic coasts. Individuals live on top of each other and form stacks with the youngest on the top. Earlier studies reported that one individual typically settles per year. If true, it is a simplified means to provide a “shell length-age” relationship for population dynamics studies, especially Production/Biomass ratio (P/B) assessment. However, estimated P/B ranges between 0.15 and 0.45 yr-1 seem low compared to those of closely-related marine invertebrates and considering the invasiveness of C. fornicata in coastal habitats. In this study, we placed artificial substrates (“tiles”) for one year in the middle of a C. fornicata colony and measured settlement. We sometimes observed more than one individual settling per stack in a year: 4% of stacks were composed by 3 individuals, 27% by 2 individuals and 69% were single specimen. On this basis, we formulated a model to better link the position of each C. fornicata within a stack to its age. In addition, the C. fornicata population was annually sampled for 5 years. Then, population dynamics parameters, density at recruitment, mortality rate, growth performance, production and P/B were estimated. We compared two cases: (i) individual age was defined by its position in stacks; (ii) individual age was corrected by the model. Recalculation moderately increased growth performance expectation (+2 to 8% per year) but greatly enhanced production and P/B (ca. 1.2 to 2.6-fold per year). Recalculated P/B values ranged from 0.55 to 0.72 yr-1. While still low, they were more consistent with published values for similar large marine invertebrates, in particular for invasive species.
(Aquatic Invasions. vol. 12, n° 1798-6540, pp. 459-468, 22/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Transcriptomic responses of the endangered freshwater mussel Margaritifera margaritifera to trace metal contamination in the Dronne River, France
The freshwater pearl mussel Margaritifera margaritifera is one of the most threatened freshwater bivalves worldwide. In this study, we aimed (i) to study the processes by which water quality might affect freshwater mussels in situ and (ii) to provide insights into the ecotoxicological significance of water pollution to natural populations in order to provide necessary information to enhance conservation strategies. M. margaritifera specimens were sampled in two close sites located upstream or downstream from an illegal dumping site. The renal transcriptome of these animals was assembled and gene transcription determined by RNA-seq. Correlations between transcription levels of each single transcript and the bioaccumulation of nine trace metals, age (estimated by sclerochronology), and condition index were determined in order to identify genes likely to respond to a specific factor. Amongst the studied metals, Cr, Zn, Cd, and Ni were the main factors correlated with transcription levels, with effects on translation, apoptosis, immune response, response to stimulus, and transport pathways. However, the main factor explaining changes in gene transcription appeared to be the age of individuals with a negative correlation with the transcription of retrotransposon-related genes. To investigate this effect further, mussels were classified into three age classes. In young, middle-aged and old animals, transcription levels were mainly explained by Cu, Zn and age, respectively. This suggests differences in the molecular responses of this species to metals during its lifetime that must be better assessed in future ecotoxicology studies.
(Environmental Science and Pollution Research. vol. 24, n° 0944-1344, pp. 27145-27159, 22/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, LEMAR, IRD, IFREMER, UBO EPE, CNRS, GeT-PlaGe, GET, GENOTOUL, UT3, ENVT, INSERM, CNRS, Toulouse INP, INRAE, INRAE, MIAT INRAE, INRAE
Adaptive response under multiple stress exposure in fish: From the molecular to individual level
Aquatic systems are subjected to various sources of stress due to global changes, such as increasingtemperature and pollution. A major challenge for the next decade will be to evaluate the combinedeffects of these multiple stressors on organisms and ecosystems. For organisms submitted to chemical,biological or physical stressors, the capacity to set up an efficient adaptive response is a fundamentalprerequisite for their long-term survival and performance. In this study, goldfish (Carassius auratus) weresubjected to individual and combined pesticide mixtures and increased temperatures to evaluate theiradaptive response in multistress conditions from the molecular to the individual level. Fish were exposedfor 16 days to a mixture of pesticides at environmental relevant concentrations (S-metolachlor, isoproturon,linuron, atrazine-desethyl, aclonifen, pendimethalin and tebuconazole) and at two temperatures(22 C and 32 C). Three major physiological traits of the stress response were measured: thehormonal response (i.e. plasma cortisol), the metabolic balance from molecular to individuals' levels(metabolomics, cellular energy allocation, energy reserves and global condition indexes), and the cellulardefense system induction (SOD, CAT and GST). Results show that (1) environmentally relevant concentrationsof pesticides lead to significant responses in fish at all biological levels; (2) the metabolicresponse depends on the nature of stress (thermal vs. chemical); and (3) fish may be unable to set up anefficient adaptive response when chemical and thermal stresses were combined, with adverse outcomesat the individuals’ level.
(Chemosphere. vol. 188, n° 0045-6535, pp. 60-72, 22/10/2026)
UT3, Comue de Toulouse, E20, ToxAlim, INRA, UT3, Comue de Toulouse, ENVT, Toulouse INP, Toulouse INP, Comue de Toulouse, INP - PURPAN, Toulouse INP, GENOTOUL, UT3, ENVT, INSERM, CNRS, Toulouse INP, INRAE, GenPhySE, INRA, ENVT, Toulouse INP, Comue de Toulouse, ENSAT, INP-ENSAT, AgroToulouse, INP-AgroToulouse, Toulouse INP, Comue de Toulouse, CNR-ISM, CNR, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
The Bengal fan: external controls on the Holocene Active Channel turbidite activity
The eastern levee of the Active Channel in the Bengal fan has been investigated in order to better understand the history of turbidite activity in this channel during the Holocene in the context of Ganges-Brahmaputra source-to-sink' system. A robust C-14-based chronostratigraphy provides high temporal resolution for reconstructing sediment accumulation history on the eastern levee of the Active Channel. Integration of this study with previous work in the area suggests that the Bengal fan has remained continually connected with the Ganges-Brahmaputra fluvial system through the Holocene, feeding through the main canyon, the Swatch of No Ground (SoNG). An intense turbidite activity occurred during a transgressive wet period from 14.5 to 9.2 ka cal. BP, followed by an abrupt shift in sedimentation at 9.2 ka cal. BP, probably due to the high sea level leading to a partial disconnection between massive river discharges and the deep turbidite system. During the last 9.2 ka cal. BP, turbidite activity is still present but irregular, likely modulated by a combination of various forcings such as monsoon variability and river migration. In total, three phases are distinguishable during this period: 9.2-5.5, 5.5-4, and 4 ka cal. BP to modern, according to the turbidite record. Unexpectedly, the Indo-Asian monsoon does not appear to be the only predominant forcing on the establishment of the Bengal fan during the Holocene because of the combination of different forcings directly affecting transfers between the Ganges-Brahmaputra and the Bengal fan as well as river migrations, delta construction, and potentially anthropogenic impact.
(The Holocene. vol. 27, n° 0959-6836, pp. 900-913, 22/10/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SCTA, UQAM, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, PALEOCEAN, LSCE, UVSQ, INSU - CNRS, CNRS, DRF (CEA), CEA, GEOPS, UP11, CNRS, EMBS, iSTeP, UPMC, CNRS