Morphological anomalies in estuarine shrimp larvae
For several years, major exoskeletal anomalies in two species of European estuarine shrimp of the genus Palaemon have been observed. The phenomenon has been described for P. longirostris and P. macrodactylus in the Gironde estuary (France) and affects all stages of the species’ life cycles: from juvenile to adult and in both wild and laboratory-reared individuals. In the present follow-up study, the effects of these anomalies in larval stages of the two species were investigated. Regular sampling across most of the saline estuary confirmed that the post-larval stages of both species were affected. The morphological anomalies (MA) observed in the larvae were of the same type as those described for the adult stages, although more limited and primarily affecting the rostrum and cephalothorax. Larvae were reared from hatching to the post-larval stage, and the appearance of the aforementioned anomalies was observed as early as in Zoea I. This was the case even in larvae whose mothers did not exhibit anomalies. For both species, the most advanced stage was the one most affected. Also, in the rearing experiment, a greater proportion of the P. macrodactylus larvae was affected than those of P. longirostris. No significant effects ofMA on size or growth rate were demonstrated for larvae of either species in this study. Nevertheless, it provides data on larval growth that were not previously available. Further rearing experiments should be considered in order to explore any demonstrable effects of these morphological anomalies.
(Crustaceana. vol. 85, n° 0011-216X, pp. 11-25, 29/08/2026)
UR EPBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Factors influencing the stable carbon isotopic composition of suspended and sinking organic matter in the coastal Antarctic sea ice environment
A high resolution time-series analysis of stable carbon isotopic signatures in particulate organic carbon (δ 13 C POC) and associated biogeochemical parameters in sea ice and surface waters provides an insight into the factors affecting δ 13 C POC in the coastal western Antarctic Peninsula sea ice environment. The study covers two austral summer seasons in Ryder Bay, northern Marguerite Bay between 2004 and 2006. A shift in diatom species composition during the 2005/06 summer bloom to near-complete biomass dominance of Proboscia inermis is strongly correlated with a large ∼10 ‰ negative isotopic shift in δ 13 C POC that cannot be explained by a concurrent change in concentration or isotopic signature of CO 2. We hypothesise that the δ 13 C POC shift may be driven by the contrasting biochemical mechanisms and utilisation of carbon-concentrating mechanisms (CCMs) in different diatom species. Specifically, very low δ 13 C POC in P. inermis may be caused by the lack of a CCM, whilst some diatom species abundant at times of higher δ 13 C POC may employ CCMs. These short-lived yet pronounced negative δ 13 C POC excursions drive a 4 ‰ decrease in the seasonal average δ 13 C POC signal, which is transferred to sediment traps and core-top sediments and consequently has the potential for preservation in the sedimentary record. This 4 ‰ difference between seasons of contrasting sea ice conditions and upper water column stratification matches the full amplitude of glacial-interglacial Southern Ocean δ 13 C POC variability and, as such, we invoke phytoplankton species changes as a potentially important factor influencing sedi-mentary δ 13 C POC. We also find significantly higher δ 13 C POC in sea ice than surface waters, consistent with autotrophic carbon fixation in a semi-closed environment and possible contributions from post-production degradation, biological utilisation of HCO − 3 and production of exopolymeric substances. This study demonstrates the importance of surface water diatom speciation effects and isotopically heavy sea ice-derived material for δ 13 C POC in Antarctic coastal environments and underlying sediments, with consequences for the utility of diatom-based δ 13 C POC in the sedimentary record.
(Biogeosciences. vol. 9, n° 1726-4170, pp. 1137-1157, 29/08/2026)
UEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, BAS, NERC
Comment on "Productivity Is a Poor Predictor of Plant Species Richness
Adler et al. (Reports, 23 September 2011, p. 1750) reported "weak and variable" relationships between productivity and species richness and dispute the "humped-back" model (HBM) of plant diversity. We show that their analysis lacks sufficient high-productivity sites, ignores litter, and excludes anthropogenic sites. If corrected, the data set of Adler et al. would apparently yield strong HBM support.
(Science. vol. 335, n° 0036-8075, pp. 1441-b, 29/08/2026)
University of Milan, UNIMI, CEBC, INRA, CNRS, Uninsubria, University of Pennsylvania, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Barred-beach morphological control on infragravity motion
A conceptual analysis of the coupling between bars and infragravity waves is performed combining laboratory experiments and numerical modeling. Experiments are carried out in a wave flume with a barred profile. The Boussinesq fully-nonlinear model SERR1D is validated with the laboratory data and a sensitivity analysis is performed next to study the influence on the infragravity wave dynamics of bar amplitude and location, and swash zone slope. A novel technique of incident and reflected motions separation that conserves temporal characteristics is applied. We observe that changing bar characteristics induces substantial variations in trapped energy. Interestingly, a modification of swash zone slope has a large influence on the reflected component, controlling amplitude and phase time-lag, and consequently on the resonant pattern. Variations of trapped infragravity energy induced by changes of swash zone slope reach 25 %. These changes in infragravity pattern consequently affect short-wave dynamics by modifying the breakpoint location and the breaking intensity. Our conceptual investigation suggests the existence of a morphological feedback through the action of evolving morphology on infragravity structures which modulates the action of short-waves on the morphology itself.
(pp. currents.24, 29/08/2026)
LEGOS, IRD, UT3, Comue de Toulouse, INSU - CNRS, CNES, CNRS, PUC, UTFSM, LEGI, UJF, Grenoble INP, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Climatically-controlled siliceous productivity in the eastern Gulf of Guinea during the last 40 000 yr
Opal content and diatom assemblages were analysed in core GeoB4905-4 to reconstruct siliceous productivity changes in the eastern Gulf of Guinea during the last 40 000 yr. Opal and total diatom accumulation rates presented low values over the considered period, except during the Last Glacial Maximum and between 15 000 calendar years Before Present (15 cal. ka BP) and 5.5 cal. ka BP, the so-called African Humid Period, when accumulation rates of brackish and freshwater diatoms at the core site were highest. Conversely, accumulation rates of windblown diatoms exhibited an opposite pattern with higher values before and after the African Humid Period and greatest values during Heinrich Events, the Younger Dryas and since 5.5 cal. ka BP. Our results demonstrate that siliceous productivity in the eastern Gulf of Guinea was directly driven by the nutrient load from local rivers, whose discharges were forced by precipitation changes over western Equatorial Africa and/or modification of the fluvio-deltaic systems forced by sea level changes. Precipitation in this region is controlled by the West African monsoon which is, in turn, partly dependent on the presence and intensity of the Atlantic Cold Tongue (ACT). Our results therefore suggest that the ACT was weakened, warmer trade winds were less vigorous, and cloud convec-tion and precipitation were greater during the AHP though centennial-to-millennial timescale dry events were observed at ∼10 cal. ka BP, ∼8.5 cal. ka BP and ∼6 cal. ka BP. Conversely , the ACT was more intense, trade winds were more vigorous and African climate was more arid during H1, the Younger Dryas and after 5.5 cal. ka BP into the present.
(Climate of the Past. vol. 8, n° 1814-9324, pp. 415-431, 29/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, IACT, CSIC, UGR, CAU
Vegetation dynamics in the Northeastern Mediterranean region during the past 23 000 yr: insights from a new pollen record from the Sea of Marmara
Abstract. High-resolution pollen analysis of core MD01-2430 from the Sea of Marmara (40°47.81' N, 27°43.51' E) allows us to reconstruct the vegetation response to climatic changes during the past 23 cal ka in the Northeastern Mediterranean. Variation in mesic/temperate forest cover indicates major climatic shifts connected to Heinrich Stadial 1, Bölling-Allerød, Younger Dryas and to the onset of the Holocene. Pollen–anthropogenic indicator approach was used to recognize human-induced landscape changes in the Sea of Marmara. The pollen-inferred onset of the Holocene occurs at ca. 11.5 cal ka, indicating that the Northeastern Mediterranean region represents a transitional zone where higher moisture availability supported an earlier forest expansion than the borderlands of the Aegean Sea and Black Sea. Two major forest retreats occurred during the Holocene at ca. 5.5 and 2.1 cal ka. The Holocene forest setbacks are in phase with previously published alkenone-inferred sea-surface temperature decreases in the Sea of Marmara reconstructed from the same core. Our new pollen record testifies the sensitivity of Mediterranean forests to changes in moisture availability, which is driven by changes in high-latitude atmospheric processes (North Atlantic Oscillations and/or Siberian High).
(Climate of the Past. vol. 8, n° 1814-9324, pp. 1941-1956, 29/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, UMR ISEM, Cirad, IRD, EPHE, PSL, UM, CNRS
Seasonal succession of estuarine fish, shrimps, macrozoobenthos and plankton: physico-chemical and trophic influence. The ironde estuary as a case study
Characterization of the structure and seasonal variability of biotic communities is essential for a better understanding of estuarine ecosystem functioning and in order to manage these highly fluctuant and naturally stressed systems. Numerous studies have investigated the role of environmental factors in controlling temporal variations in biotic communities. However, most have concluded that the explanatory power of physico-chemical variables was significant but not sufficient to explain ecological dynamics. The aim of the present study was to put forward the importance of trophic interactions as an additional structuring factor of species seasonal variability by examining simultaneous dynamics of all estuarine biotic communities, with the example of the oligo-mesohaline area of the Gironde estuary (SW France) as a case study. Data on the main biological groups (fish, shrimps, macrozoobenthos and plankton) sampled during a five-year period (2004-2008) at monthly intervals using a well standardized protocol, as well as data on environmental variables, were compiled here for the first time. According to species composition, results indicated that the Gironde estuary is used as a nursery, feeding, resident and migratory habitat. Results showed that, for almost all species, strong seasonal fluctuations occurred with a succession of species, indicating an optimization of the use of the available resources over a typical year by estuarine biological communities. Multivariate analyses discriminated four seasonal groups of species with two distinctive ecological seasons. A clear shift in July indicated a biomass transfer from a “planktonic phase” to a “bentho-demersal phase”, corresponding to spring and summer-autumn periods, respectively. In regard to the temporal fluctuations of dominant species of all biological groups, this study highlighted the possible influence of trophic relationships, predation in particular, on seasonal variations in species abundance, in addition to the physico-chemical influence. This study enabled us to synthesize crucial seasonal data and to discuss their integration into seasonal models of estuarine functioning and/or specific prey-predator models. In a global change context, prey abundance variations could generate changes in the temporal dynamics of their predators (and conversely), and potentially in the functioning of the whole estuarine system.
(Estuarine, Coastal and Shelf Science. vol. 112, n° 0272-7714, pp. 243-254, 29/08/2026)
UR EPBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Remediation of a watershed contaminated by heavy metals: A 2-year field biomonitoring of periphytic biofilms
This study focuses on an industrial contamination site subjected to remediation processes since 2007 in the Riou-Mort watershed (southw st France). The purpose was to assess the first impacts of remediation on periphytic biofilms, and was performed during two years of biomonitoring. Periphytic biofilms were collected on glass slides immersed 24 days at different sites along the contamination gradient for 12 colonisation cycles. Metal contaminations (Cd and Zn) were analysed in biofilms and the evolution of diatom communities was assessed, integrating teratology quantifications. Despite remediation work initiated at the industrial site, this study demonstrated the persistence of metal contamination in water, as well as in biofilms. In addition, our data, showed that the remediation process was initially marked by an increase in metal contamination in the river, with increasing diatom community shifts. Metal-contaminated biofilms presented decreasing species diversities and were dominated by metal-resistant species such as Eolimna minima, whom abundances increased in 2010 reaching 57.2 ± 10%. No significant decrease in metal accumulation was observed and total Cd content in biofilms collected downstream the industrial site ranged from 772.7 ± 88 in July 2009 to 636.9 ± 20 μg/gDW in July 2 010. Results obtained on artificial substrates were compared with those of natural substrates and showed similar diatom communities and abundances of deformed diatoms but lower diversities. This ensured that glass slide subtrates gave a good representation of periphytic biofilm health . Finally, results were compared to studies performed before the remediation process and this did not reveal a decrease of metal accumulation in biofilms nor shifts in taxonomic composition of the communities, rather the remaining dominance of metal-resistant species such as E. minima was confirmed.
(Science of the Total Environment. vol. 425, n° 0048-9697, pp. 242-253, 29/08/2026)
UR REBX, IRSTEA, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS
Evidence for a Complex Relationship between Antibiotics and Antibiotic-Resistant Escherichia Coli: From Medical Center Patients to a Receiving Environment
The aim of this study was to investigate the relationship between antibiotics and antibiotic-resistant fecal bacteria (E. coli) in water along a medical center−wastewater treatment plant−river continuum (4 km). A multiresidue chemical analysis methodology, using solid phase extraction coupled with liquid chromatography tandem mass spectrometry, was performed to detect whether low levels of contamination by 34 antibiotics were related to antibiotic resistance of E. coli and antibiotic use. The contamination of water by antibiotics and antibiotic-resistant E. coli decreased along the continuum. Although amoxicillin was predominantly prescribed, only ofloxacin (1 ng*L−1) and sulfamethoxazole (4 ng*L−1) persisted in the river. At the retirement home, in the medical center, even though no tetracycline and sulfamethoxazole were consumed, the highest occurrences of antibiotic resistance were in classes of quinolones (42.0%), sulfonamides (24.0%), tetracyclines (38.0%), and penicillins (38.0%), mainly due to the presenceof multiple antibiotic-resistance genes on class 1 integrons. Along the continuum, the occurrence of E. coli resistant to antibiotics and those carrying class 1 integrons decreased in water samples (p-value <0.001). Interestingly, in the river, only persistent antibiotic compounds (ofloxacin, sulfamethoxazole) were found, but they did not correspond to the major resistances (tetracycline, amoxicillin) of E. coli.
(Environmental Science and Technology. vol. 46, n° 0013-936X, pp. 1859−1868, 29/08/2026)
M2C, UNICAEN, NU, INSU - CNRS, UNIROUEN, NU, CNRS, EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, SCALE, ULH, NU, UNIROUEN, NU, CNRS
La variabilité climatique rapide de la dernière période glaciaire et l’extinction des Néandertaliens
(pp. 107-121, 29/08/2026)
EPOC, EPHE, PSL, UB, INSU - CNRS, CNRS, PACEA, UB, CNRS