Fast dentification of overlapping fluorescence spectra of oil species based on LDA and two-dimensional convolutional neural network.

Although most petroleum oil species can be identified by their fluorescence spectra, overlapping fluorescence spectra make identification difficult. This study aims to address the issue that fluorescence spectroscopy is ineffective in identifying overlapping oil species. In this study, an equivalent model of overlapping oil species with fluorescence spectra was established. The linear discriminant analysis (LDA)-assisted machine learning (ML) algorithms K nearest neighbor (KNN), decision tree (DT), and random forest (RF) improved the identification of fluorescent spectrally overlapping oil species for diesel-lubricant oils. The identification accuracies of two-dimensional convolutional neural network (2DCNN), LDA combined with the ML algorithms effectively all 100 %. Furthermore, Partial Least Squares Regression (PLSR) algorithm, Support Vector Regression (SVR) algorithm, DT regression algorithm, and RF regression algorithm were also used to identify the lubricant concentration in diesel-lubricant oils. The coefficient of determination of the DT was 1, and the root-mean-square error was 0, which identified the concentration of lubricant oils in them accurately and without error.

Sea buckthorn extract mitigates chronic obstructive pulmonary disease by suppression of ferroptosis via scavenging ROS and blocking p53/MAPK pathways.

ETHNOPHARMACOLOGICAL RELEVANCE: Sea buckthorn (Hippophae rhamnoides), a traditional Tibetan medicinal herb, exhibits protective effects against cardiovascular and respiratory diseases. Although Sea buckthorn extract (SBE) has been confirmed to alleviate airway inflammation in mice, its therapeutic effect and underlying mechanism on chronic obstructive pulmonary disease (COPD) requires further clarification. AIM OF THE STUDY: To elucidate the alleviative effect and molecular mechanism of SBE on lipopolysaccharides (LPS)/porcine pancreatic elastase (PPE)-induced COPD by blocking ferroptosis. METHODS: The anti-ferroptotic effects of SBE were evaluated in human BEAS-2B bronchial epithelial cells using CCK8, RT-qPCR, western blotting, and transmission electron microscopy. Transwell was employed to detect chemotaxis of neutrophils. COPD model was induced by intranasally administration of LPS/PPE in mice and measured by alterations of histopathology, inflammation, and ferroptosis. RNA-sequencing, western blotting, antioxidant examination, flow cytometry, DARTS, CETSA, and molecular docking were then used to investigate its anti-ferroptotic mechanisms. RESULTS: In vitro, SBE not only suppressed erastin- or RSL3-induced ferroptosis by suppressing lipid peroxides (LPOs) production and glutathione (GSH) depletion, but also suppressed ferroptosis-induced chemotactic migration of neutrophils via reducing mRNA expression of chemokines. In vivo, SBE ameliorated LPS/PPE-induced COPD phenotypes, and inhibited the generation of LPOs, cytokines, and chemokines. RNA-sequencing showed that p53 pathway and mitogen-activated protein kinases (MAPK) pathway were implicated in SBE-mediated anti-ferroptotic action. SBE repressed erastin- or LPS/PPE-induced overactivation of p53 and MAPK pathway, thereby decreasing expression of diamine acetyltransferase 1 (SAT1) and arachidonate 15-lipoxygenase (ALOX15), and increasing expression of glutathione peroxidase 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11). Mechanistically, erastin-induced elevation of reactive oxygen species (ROS) was reduced by SBE through directly scavenging free radicals, thereby contributing to its inhibition of p53 and MAPK pathways. CETSA, DARTS, and molecular docking further showed that ROS-generating enzyme nicotinamide adenine dinucleotide phosphate (NADPH) oxidase 4 (NOX4) may be the target of SBE. Overexpression of NOX4 partially impaired the anti-ferroptotic activity of SBE. CONCLUSION: Our results demonstrated that SBE mitigated COPD by suppressing p53 and MAPK pro-ferroptosis pathways via directly scavenging ROS and blocking NOX4. These findings also supported the clinical application of Sea buckthorn in COPD therapy.

Cotransport of nanoplastics with nZnO in saturated porous media: From brackish water to seawater.

The ocean serves as a repository for various types of artificial nanoparticles. Nanoplastics (NPs) and nano zinc oxide (nZnO), which are frequently employed in personal care products and food packaging materials, are likely simultaneously released and eventually into the ocean with surface runoff. Therefore, their mutual influence and shared destiny in marine environment cannot be ignored. This study examined how nanomaterials interacted and transported through sea sand in various salinity conditions. Results showed that NPs remained dispersed in brine, while nZnO formed homoaggregates. In seawater of 35 practical salinity units (PSU), nZnO formed heteroaggregates with NPs, inhibiting NPs mobility and decreasing the recovered mass percentage (Meff) from 24.52% to 12.65%. In 3.5 PSU brackish water, nZnO did not significantly aggregate with NPs, and thus barely affected their mobility. However, NPs greatly enhanced nZnO transport with Meff increasing from 14.20% to 25.08%, attributed to the carrier effect of higher mobility NPs. Cotransport from brackish water to seawater was simulated in salinity change experiments and revealed a critical salinity threshold of 10.4 PSU, below which the mobility of NPs was not affected by coexisting nZnO and above which nZnO strongly inhibited NP transport. This study highlights the importance of considering the mutual influence and shared destiny of artificial nanoparticles in the marine environment and how their interaction and cotransport are dependent on changes in seawater salinity.

Deep-Pelagic Fishes Are Anything But Similar: A Global Synthesis.

Deep-pelagic fishes are among the most abundant vertebrates on Earth. They play a critical role in sequestering carbon, providing prey for harvestable fishing stocks and linking oceanic layers and trophic levels. However, knowledge of these fishes is scarce and fragmented, hampering the ability of both the scientific community and stakeholders to address them effectively. While modelling approaches incorporating these organisms have advanced, they often oversimplify their functional and ecological diversity, potentially leading to misconceptions. To address these gaps, this synthesis examines the biodiversity and ecology of global deep-pelagic fishes. We review pelagic ecosystem classifications and propose a new semantic framework for deep-pelagic fishes. We evaluate different sampling methods, detailing their strengths, limitations and complementarities. We provide an assessment of the world's deep-pelagic fishes comprising 1554 species, highlighting major groups and discussing regional variability. By describing their morphological, behavioural and ecological diversity, we show that these organisms are far from homogeneous. Building on this, we call for a more realistic approach to the ecology of deep-pelagic fishes transitioning between very different ecological niches during diel vertical migrations. To facilitate this, we introduce the concept of 'diel-modulated realised niche' and propose a conceptual model synthesising the multiple drivers responsible for such transitions.

Quantitative real-time PCR assays for species-specific detection and quantification of Baltic Sea spring bloom dinoflagellates.

In the Baltic Sea, the dinoflagellates Apocalathium malmogiense, Biecheleria baltica, and Gymnodinium corollarium are important contributors to the spring bloom. However, their relative contribution to the bloom community cannot be unambiguously determined by conventional light microscopy due to a lack of resolution of distinctive morphological features of the three species. Here, we describe a molecular approach based on a quantitative real-time polymerase chain reaction (qPCR) primer and probe system, targeting the ITS1 and ITS2 regions of the rRNA gene for all three species and enabling their quantification. The specificity of the method was demonstrated using monocultures of A. malmogiense, B. baltica, G. corollarium as well as three other dinoflagellate species co-occurring in the Baltic Sea during spring and validated using field-collected phytoplankton samples.

Impacts of shellfish and macroalgae mariculture on the seawater carbonate system and air-sea CO2 flux in Haizhou Bay, China.

China is the largest mariculture country, and shellfish and algae output ranks first, showing high carbon sink capacity. In recent years, the single cultivation of macroalgae (Pyropia yezoensis) has been changed to macroalgae-shellfish mariculture in Haizhou Bay to increase the yield of P. yezoensis and improve the water environment quality. In this study, four surveys were carried out in July 2022 during the monoculture period of oyster (Magallana gigas), as well as at different stages of P. yezoensis culture (head-crop period, November 2022, peak growing season, January 2023, and end of harvesting, March 2023) in the mariculture and the surrounding waters of Haizhou Bay. The effects of different stages of culture on the seawater environment and seasonal and spatial variations in the carbonate system were analyzed, and the carbon sink capacity was preliminarily estimated. The results showed that in summer, the calcification of M. gigas and the primary production process of phytoplankton effectively reduced the dissolved inorganic carbon (DIC) level in the culture area. The culture area acts as a CO2 sink, with an average air-sea CO2 flux of -4.5 mmol m-2 d-1. During the polyculture period, the P. yezoensis culture activities maintained the stability of the seawater carbonate system, and the culture area shows strong CO2 sinks, with the average air-sea CO2 flux of -24.10 mmol m-2 d-1, -37.68 mmol m-2 d-1, and -38.99 mmol m-2 d-1, respectively. The absorption of CO2 by large-scale cultured P. yezoensis through the "biological pump" effect is the main factor affecting the CO2 exchange process at the air-sea interface, and the absorption rate of CO2 by P. yezoensis at the mature stage is higher than that at the growth stage before harvesting. The study revealed that macroalgae-shellfish mariculture could promote mutual growth, alleviate environmental pressure, and enhance the carbon sink of the culture area. The relationship between mariculture and the carbon cycle of a mariculture ecosystem is very complicated, and its biochemical process should be given great attention for further study.

Delineating morphological traits of oceanic micro-phytoplankton as potential ecological indicators.

The micro-phytoplankton (>20 µm) adaptations and resilience were assessed using morphological traits (shape, surface-to-volume ratio; S:V, and greatest-axial-linear-dimension; GALD) from sea-surface and different SCML-depths (shallow:20-50 m, intermediate:50-100 m, and deep:100-140 m) across different bioregions of Indian Ocean. The dominant simple elongated phytoplankton-geometric-shapes (PGSs) and morphological traits showed distinct north-south distribution and varied with light and nutrient availability. Further, SCML and corresponding sea-surface PGS will be similar or dissimilar if the former is located within or deeper than mixed-layer depth. Also, simple and complex PGS contribution gradually decreases and increases with increasing depth. Additionally, shallow SCML-PGS showed low-S:V and high-GALD while vice-versa for intermediate/deep SCML-PGS due to phenotypic plasticity behavior. Overall, only simple-PGS (cylinder, elliptic-prism, and prism-on-parallelogram) showed strong adaptive behavior through phenotypic plasticity and were highlighted as potential ecological tracers to address ecological impact of oceanographic processes (including coastal eutrophication, and aerosol deposition) linked to nutrient and light availability in predicted ocean change scenarios.

The Potential of Artificial Cells Functioning under In Situ Deep-Sea Conditions.

Artificial cells with reconstructed cellular functions could serve as practical protocell models for studying the early cellular life on the Earth. Investigating the viability of protocell models in extreme environments where life may have arisen is important for advancing origin-of-life research. Here, we tested the survivability of lipid membrane vesicles in deep-sea environments. The vesicles were submerged in the deep-sea floor with a human-occupied vehicle. Although most of the vesicles were broken, some vesicles maintained a spherical shape after the dives. When a cell-free protein synthesis system was encapsulated inside, a few vesicles remained even after a 1,390 m depth dive. Interestingly, such artificial cells could subsequently synthesize protein in a nutrient-rich buffer solution. Together with on shore experiments showing artificial cells synthesized protein under high pressure, our results suggest artificial cells may be able to express genes in deep-sea environments where thermal energy is available from hydrothermal vents.

Functional effects of subsidies and stressors on benthic microbial communities along freshwater to marine gradients.

Leaf litter in coastal wetlands lays the foundation for carbon storage, and the creation of coastal wetland soils. As climate change alters the biogeochemical conditions and macrophyte composition of coastal wetlands, a better understanding of the interactions between microbial communities, changing chemistry, and leaf litter is required to understand the dynamics of coastal litter breakdown in changing wetlands. Coastal wetlands are dynamic systems with shifting biogeochemical conditions, with both tidal and seasonal redox fluctuations, and marine subsidies to inland habitats. Here, we investigated gene expression associated with various microbial redox pathways to understand how changing conditions are affecting the benthic microbial communities responsible for litter breakdown in coastal wetlands. We performed a reciprocal transplant of leaf litter from four distinct plant species along freshwater-to-marine gradients in the Florida Coastal Everglades, tracking changes in environmental and litter biogeochemistry, as well as benthic microbial gene expression associated with varying redox conditions, carbon degradation, and phosphorus acquisition. Early litter breakdown varied primarily by species, with highest breakdown in coastal species, regardless of the site they were at during breakdown, while microbial gene expression showed a strong seasonal relationship between sulfate cycling and salinity, and was not correlated with breakdown rates. The effect of salinity is likely a combination of direct effects, and indirect effects from associated marine subsidies. We found a positive correlation between sulfate uptake and salinity during January with higher freshwater inputs to coastal areas. However, we found a peak of dissimilatory sulfate reduction at intermediate salinity during April when freshwater inputs to coastal sites are lower. The combination of these two results suggests that sulfate acquisition is limiting to microbes when freshwater inputs are high, but that when marine influence increases and sulfate becomes more available, dissimilatory sulfate reduction becomes a key microbial process. As marine influence in coastal wetlands increases with climate change, our study suggests that sulfate dynamics will become increasingly important to microbial communities colonizing decomposing leaf litter.

Identification of plankton habitats in the North Sea.

The definition of an ecological niche makes it possible to anticipate the responses of a species to changing environmental conditions. Broad tolerance limits and a paucity of readily observable niches in the pelagic zone make it difficult to anticipate responses of the plankton community related to anthropogenic or environmental changes. Plankton distributions are closely linked to climate change and shape the seascape for higher trophic levels, so monitoring plankton distributions and defining ecological niches will help to understand and predict ecosystem responses. Here we apply a machine learning autoencoder and a density-based clustering algorithm to high-frequency datasets sampled with a ROTV Triaxus in the North Sea. The results indicate that in this highly dynamic environment, local hydrography prevents niche-based separation of plankton species at the sub-mesoscale, despite the availability of different habitats. Plankton patches were associated with naturally occurring frontal systems and anthropogenically induced upwelling-downwelling dipoles in the vicinity of offshore wind farms (OWFs).

Morphology and Phylogenetic Position of the Sargassum Nudibranch Scyllaea fulva Quoy & Gaimard, 1824 (Nudibranchia: Scyllaeidae): First Record in Hong Kong.

Scyllaeidae is a small group of nudibranchs comprising three genera (Scyllaea, Notobryon, and Crosslandia) with striking morphological similarities, making their identification challenging based on external features alone. Previous studies have highlighted the significance of central radular teeth in distinguishing Notobryon from Scyllaea and Crosslandia. The genus Scyllaea, commonly known as the sargassum nudibranch, currently consists of only two valid species, Scyllaea pelagica and Scyllaea fulva. These species inhabit seaweed Sargassum spp., feeding on hydroids. During a biodiversity survey conducted in April 2023, seven sargassum nudibranch individuals were collected from the seaweed Sargassum spp. at a depth of 2 meters in Tai She Wan through SCUBA diving. Initially, the specimens were misidentified based on their resemblance to Notobryon wardi and previous local records. However, thorough morphological and molecular examinations confirmed them to be Scyllaea fulva, representing the first record of this species in Hong Kong. Notably, our specimens lacked the blue spots observed in specimens from Thailand and the West Pacific Ocean, as reported in previous studies. Internally, a pineapple-like structure formed a honeycomb pattern on the surface of the masticatory edge of the jaw flap, with the presence of central radular teeth. A Maximum Likelihood tree analysis revealed Crosslandia to be the sister group of Scyllaea. Comparative analysis of intra-specific distances between individuals from the Philippines, French Polynesia, and Hong Kong indicated a close relationship between the Hong Kong specimens and those from the Philippines. Furthermore, we provide a detailed description of the external and internal morphology of Scyllaea fulva in this paper, integrating valuable morphological information for future species identification purposes.

Thaumarchaeota from deep-sea methane seeps provide novel insights into their evolutionary history and ecological implications.

BACKGROUND: Ammonia-oxidizing archaea (AOA) of the phylum Thaumarchaeota mediate the rate-limiting step of nitrification and remove the ammonia that inhibits the aerobic metabolism of methanotrophs. However, the AOA that inhabit deep-sea methane-seep surface sediments (DMS) are rarely studied. Here, we used global DMS metagenomics and metagenome-assembled genomes (MAGs) to investigate the metabolic activity, evolutionary history, and ecological contributions of AOA. Expression of AOA-specific ammonia-oxidizing gene (amoA) was examined in the sediments collected from the South China Sea (SCS) to identify their active ammonia metabolism in the DMS. RESULTS: Our analysis indicated that AOA contribute > 75% to the composition of ammonia-utilization genes within the surface layers (above 30 cm) of global DMS. The AOA-specific ammonia-oxidizing gene was actively expressed in the DMS collected from the SCS. Phylogenomic analysis of medium-/high-quality MAGs from 18 DMS-AOA indicated that they evolved from ancestors in the barren deep-sea sediment and then expanded from the DMS to shallow water forming an amoA-NP-gamma clade-affiliated lineage. Molecular dating suggests that the DMS-AOA origination coincided with the Neoproterozoic oxidation event (NOE), which occurred ~ 800 million years ago (mya), and their expansion to shallow water coincided with the Sturtian glaciation (~ 713 mya). Comparative genomic analysis suggests that DMS-AOA exhibit higher requirement of carbon source for protein synthesis with enhanced genomic capability for osmotic regulation, motility, chemotaxis, and utilization of exogenous organic compounds, suggesting it could be more heterotrophic compared with other lineages. CONCLUSION: Our findings provide new insights into the evolutionary history of AOA within the Thaumarchaeota, highlighting their critical roles in nitrogen cycling in the global DMS ecosystems. Video Abstract.

Dune Hares: Population Indices, Home Range Size, and Habitat Selection of the European Hare on a Danish Island.

Population indices, such as transect counts of animals, can provide important information concerning population changes over time. Moreover, data concerning the home range size and habitat selection of individuals can provide valuable insight into spatial requirements of animals and how they can adapt to variable environments. Here, we describe the population development of European hares (Lepus europaeus) and investigated home range sizes and habitat selection of six radio-tagged individuals on the small (80 ha) Danish Wadden Sea island Langli. The average minimum hare population density from 1983 to 1997 was 64 ± 36 (mean ± SD) hares/km2, with hare numbers varying among years and seasons. The average home range size was 23.3 (CI: 18.9-28.7) ha, which is comparable to agricultural areas of high structural diversity. Moreover, hare habitat selection was generally bimodal, with hares moving over larger areas and selecting marsh habitat for foraging during nighttime, and dune and grassland habitat for resting during daytime, especially during winter. Combined, our results indicate that hare abundance and space use in the dunal landscape of Langli Island were similar to agricultural areas of comparatively high habitat quality. Thus, dunal marsh landscapes offer high-quality habitat for hares and might be of importance as population strongholds at a time when hare populations are declining in many agricultural areas across Europe.

How much do we know about the microplastic distribution in the Mediterranean Sea: A comprehensive review.

The Mediterranean Sea is one of the most heavily polluted regions. Here we comprehensively review the current state of microplastic pollution in the Mediterranean Sea and the Black Sea. A total of 284 studies published between 2012 and 2023 were analyzed, revealing a continuous increase in research efforts. Our review encompassed microplastic monitoring studies across five environmental matrices: the sea surface, water column, intertidal sediment, bottom sediment, and biota, with a predominant focus observed in biota-related studies with fish, molluscs, crustaceans, and echinoderms being the primary focus. The study found that species such as Mullus barbatus, Mytilus galloprovincialis, Nephrops norvegicus, and Holothuria tubulosa are frequently studied species. The review also emphasizes the lack of standardized methodologies across studies, which hampers the comparability of results and the synthesis of data. The findings of this study provide a critical evaluation of the current research landscape and identify significant knowledge gaps, particularly in the underrepresented southern Mediterranean and Black Sea regions, calling for more balanced research efforts and methodological consistency in future studies.

Hydrocarbon-degrading microbial populations in permanently cold deep-sea sediments in the NW Atlantic.

Permanently cold deep-sea sediments (2500-3500 m water depth) with and without indications of thermogenic hydrocarbon seepage were exposed to naphtha to examine the presence and potential of cold-adapted aerobic hydrocarbon-degrading microbial populations. Monitoring these microcosms for volatile hydrocarbons by GC-MS revealed sediments without in situ hydrocarbons responded more rapidly to naphtha amendment than hydrocarbon seep sediments overall, but seep sediments removed aromatic hydrocarbons benzene, toluene, ethylbenzene and xylene (BTEX) more readily. Naphtha-driven aerobic respiration was more evident in surface sediment (0-20 cmbsf) than deeper anoxic layers (>130 cmbsf) that responded less rapidly. In all cases, enrichment of Gammaproteobacteria included lineages of Oleispira, Pseudomonas, and Alteromonas known to be associated with marine oil spills. On the other hand, taxa known to be prevalent in situ and diagnostic for thermogenic hydrocarbon seepage in deep sea sediment, did not respond to naphtha amendment. This suggests a limited role for these prevalent seep-associated populations in the context of aerobic hydrocarbon biodegradation.

Cell-wide arrangement of Golgi/RE units depends on the microtubule organization.

We have previously shown that Golgi stacks and recycling endosomes (REs) exist as Golgi/RE units in sea urchin embryos. In this study, we showed that Golgi/RE units were scattered throughout the cytoplasm at early developmental stages but gathered to form a "Golgi ring" surrounding the centric REs at the blastula stage. This change in the cell-wide arrangement of Golgi/RE units coincided with a dramatic change in microtubule organization from a randomly oriented cortical pattern to radial arrays under the apical plasma membrane. A single gigantic Golgi apparatus surrounding centric RE is clearly associated with the center of the radial microtubule arrays. Furthermore, we found that in some animal species belonging to different clades, Golgi stacks lack lateral connections but are likely centralized by microtubule motors. These results suggest that Golgi centralization depends on the organization of the microtubule array in addition to the lateral linking between Golgi stacks. Key words: Golgi stack, recycling endosome, Golgi-ribbon, microtubule, cilium, sea urchin, ascidian.

Incorporation of plastic debris into the nests of great cormorants (Phalacrocorax carbo sinensis) in the Gulf of Finland.

Several bird species are known to utilise marine debris among their nest materials in different parts of the world. This study examines the prevalence of debris in cormorant nests in the Gulf of Finland, focusing mainly on plastic debris. 200 nests were sampled on four different nesting islets, and plastic debris in the nest was counted and classified according to their type, colour, origin and polymer type. In total, 58 % of the nests contained debris (95 % plastics), but the prevalence of debris in the nests varied between the colonies. Core nests contained more debris than periphery nests. The relative number of threadlike plastics in the nests was higher than that in the surrounding environment, indicating active selection by cormorants. Based on the results, nest surveys could be a useful tool in evaluating the effectiveness of certain reduction measures aiming to tackle marine plastic pollution in the Baltic Sea.

Sea cucumber-derived extract can protect skin cells from oxidative DNA damage and mitochondrial degradation, and promote wound healing.

Our skin serves as the primary barrier against external environmental insults, the latter of which can cause oxidative stress within cells, while various bioactive peptides sourced from natural resources hold promise in protecting cells against such oxidative stress. In this study, we investigate the efficacy of a low molecular weight extract from the sea cucumber Apostichopus japonicus, denoted as Sample-P, in facilitating cell migration and wound healing under oxidative stress conditions in skin cells. The naturally derived compound is a highly complex mix of peptides exhibiting antioxidative properties, as highlighted through liquid chromatography-mass spectrometry peptide screening and an in vitro antioxidant assay. Our results demonstrate that Sample-P is capable of promoting cell migration while preventing severe stress responses such as visible through mTOR expression. To further identify the molecular pathways underpinning the overall protective mechanism of Sample-P, we have utilised a proteomics approach. Our data reveal that Sample-P regulates protein expression associated with ribosomal pathways, glycolysis/gluconeogenesis and protein processing in the endoplasmic reticulum (ER), which help in preserving DNA integrity and safeguarding cellular organelles, such as mitochondria and the ER, under oxidative stress conditions in skin cells. In summary, in the presence of H2O2, Sample-P exhibits antioxidative properties at both molecular and cellular levels, rendering it a promising candidate for topical skin treatment to wound healing and to address age-related skin conditions.

Habitat specificity modulates the bacterial biogeographic patterns in the Southern Ocean.

Conceptual biogeographic frameworks have proposed that the relative contribution of environmental and geographical factors on microbial distribution depends on several characteristics of the habitat (e.g. environmental heterogeneity, species diversity, proportion of specialist/generalist taxa), all of them defining the degree of habitat specificity, but few experimental demonstrations exist. Here, we aimed to determine the effect of habitat specificity on bacterial biogeographic patterns and assembly processes in benthic coastal ecosystems of the Southern Ocean (Patagonia, Falkland/Malvinas, Kerguelen, South Georgia and King George Islands), using 16S rRNA gene metabarcoding. The gradient of habitat specificity resulted from a 'natural experimental design' provided by the Abatus sea urchin model, from the sediment (least specific habitat) to the intestinal tissue (most specific habitat). The phylogenetic composition of the bacterial communities showed a clear differentiation by site, driven by a similar contribution of geographic and environmental distances. However, the strength of this biogeographic pattern decreased with increasing habitat specificity: sediment communities showed stronger geographic and environmental divergence compared to gut tissue. The proportion of stochastic and deterministic processes contributing to bacterial assembly varied according to the geographic scale and the habitat specificity level. For instance, an increased contribution of dispersal limitation was observed in gut tissue habitat. Our results underscore the importance of considering different habitats with contrasting levels of specificity to better understand bacterial biogeography and assembly processes over oceanographic scales.

Compilation of Consolidation Properties Data of Champlain Sea Clay from Ottawa Region.

Estimation of consolidation settlements in fine-grained soils due to various civil infrastructure loads is traditionally based on results derived from consolidation tests performed on undisturbed soil samples, combined with the data of other soil properties. In many geotechnical engineering applications, consolidation settlements are also estimated using empirical consolidation parameters derived from basic soil properties. This approach relies on correlations from the literature to bypass the time-consuming and expensive sampling techniques, laboratory testing, and other associated expenses. However, these correlations may not provide reasonable consolidation settlement estimations as these correlations are typically developed without considering the influence of stress history, geology, salinity of pore water, gradation, soil fabric, and chemical properties of the soils. This is especially true for Champlain Sea clay deposits from Eastern Ontario region of Canada that are typically with heterogeneous site conditions and exhibit spatial variability of soil properties. In this paper, data from the published literature and industrial and government reports on sensitive Champlain Sea clays were gathered for the Ottawa region. The data collection and clean-up methodology towards enhancing the reliability of the gathered data is comprehensively discussed. The summarized data from this study can be used with a greater degree of confidence towards developing reliable correlations in the estimation of consolidation settlements in geotechnical engineering practice.