Terrestrial Environments Research Articles

Insights into organic matter source and depositional environments of shales from the Ponta Grossa Formation in Parana basin, Brazil

Marine transgression events and plant species' evolution to terrestrial environments increased the amount of organic matter in sediments during the Devonian Period. Subsequently, a bituminous material known as shale was formed, containing organic compounds that enable the reconstruction of environmental conditions from previous eras. These rock formation events are recorded worldwide, however, in the Ponta Grossa Formation, southern Brazil, a deeper understanding of samples from the Devonian Period is necessary. The goal of this study was to understand the regional environmental conditions, the origin of the organic matter, and the degree of maturation of the bituminous material. Shale samples were collected from an outcrop on the eastern border of the Paraná Basin and processed in the laboratory to obtain the saturated hydrocarbons fraction posteriorly analyzed. The results indicate a poorly oxygenated environment, with various salinity levels, mixed organic sources, and a high thermal maturity of the samples. The analysis of compound hydrocarbons elucidates the environmental conditions during the Devonian Period in the Ponta Grossa Formation, providing inferences applicable to the stratigraphic interval represented by this record and within the domain of the sampled area.

Clathrate Hydrate-Solid Surface Adhesive Shear Strength Measurements on Carbon Steel Surfaces.

Oil and gas flowlines operating in subsea or cold terrestrial environments face the risk of forming hydrate deposits and plugs. The pressure differential across a hydrate plug can cause the plug to detach from the pipe wall and travel through the pipeline, potentially impacting a bend or inline equipment, causing damage or injury to personnel. Therefore, the hydrate-solid adhesive shear strength is of interest in estimating the maximum allowable differential pressure across a plug during depressurization procedures before the plug is likely to detach from the pipe wall. Quantifying the changes in adhesive shear strength with time and operational conditions is essential in estimating the potential of hydrate deposits to slough from the pipe wall. This work used a force meter with a cylindrical "pig-style" probe mounted to a single axis motorized test stand to measure the force required to dislodge model THF structure II hydrate plugs in carbon steel pipes. Profilometry measurements were used to quantify the mean surface roughness and relative peak frequency of the pipe surfaces. Contact angle measurements were performed of a water droplet on pristine, sanded, and corroded pipe surfaces immersed in nonpolar solvents. The adhesive shear strength of the hydrate plugs was measured for different subcoolings, solid surface roughness, and surface wettabilities. Subcooling was shown to impact the hydrate-solid adhesive shear strength, and a mixed adhesive/cohesive failure mechanism was observed at the highest subcooling tested. The surface roughness and wettability were also shown to influence the hydrate-solid adhesive shear strength, with readily wetting corroded and sanded carbon steel surfaces resulting in greater interface adhesive strength than the pristine carbon steel system. This is likely due to a Wenzel wetting mode at the interface, resulting in a higher ratio of actual to apparent wetted area as well as establishing a mechanical interlocking mechanism.

A Genomics-Based Discovery of Secondary Metabolite Biosynthetic Gene Clusters in the Potential Novel Strain Streptomyces sp. 21So2-11 Isolated from Antarctic Soil.

Streptomyces species are attractive sources of secondary metabolites that serve as major sources of antibiotics and other drugs. In this study, genome mining was used to determine the biosynthetic potential of Streptomyces sp. 21So2-11 isolated from Antarctic soil. 16S rRNA gene sequencing revealed that this strain is most closely related to Streptomyces drozdowiczii NBRC 101007T, with a similarity of 98.02%. Genome comparisons based on average nucleotide identity (ANI) and digital DNA-DNA hybridization (dDDH) showed that strain 21So2-11 represents a novel species of the genus Streptomyces. In addition to a large number of genes related to environmental adaptation and ecological function, a total of 28 putative biosynthetic gene clusters (BGCs) responsible for the biosynthesis of known and/or novel secondary metabolites, including terpenes, lantipeptides, polyketides, nonribosomal peptides, RiPPs and siderophores, were detected in the genome of strain 21So2-11. In addition, a total of 1456 BGCs were predicted to contribute to the biosynthesis of more than 300 secondary metabolites based on the genomes of 47 Streptomyces strains originating from polar regions. The results indicate the potential of Streptomyces sp. 21So2-11 for bioactive secondary metabolite production and are helpful for understanding bacterial adaptability and ecological function in cold terrestrial environments.

Bioaccumulation of trace metals in edible terrestrial snails, Theba pisana and Otala spp., in a dumpsite area in Morocco and assessment of human health risks for consumers.

This study assessed the bioaccumulation patterns of five trace metals (Cd, Cr, Co, Cu, and Zn) in two edible snail species, Theba pisana and Otala spp., collected from a dumpsite in Safi City, Morocco. The results indicated that bioaccumulation might be species-specific, as metal concentration profiles varied between the two snail species. Additionally, higher metal levels in the dumpsite snails confirmed their potential as bioindicators of trace metal pollution in terrestrial environments. However, the distribution of trace elements within the edible parts of the snails showed marked unevenness, with the viscera accumulating more metals than the foot. The study also evaluated the potential human health risks associated with consuming these snails. Trace metal levels in the edible parts exceeded most international safety thresholds. The estimated daily intakes (EDIs) of trace metals through snail consumption were below the provisional tolerable daily intakes (PTDIs) for both children and adults, suggesting that daily consumption is generally safe. Nonetheless, the hazard index (HI) indicated that children might face health risks from long-term consumption of contaminated snails (HI > 1), while adults are less likely to experience such complications (HI < 1). The total target carcinogenic risk (TTCR) was below 1E-04 for both children and adults, indicating negligible to acceptable carcinogenic risks for all consumer groups.

Aluminum substitution stabilizes organic matter in ferrihydrite transforming into hematite: A molecular analysis

The association of soil organic matter (SOM) with iron (Fe) oxyhydroxides, particularly ferrihydrite, plays a pivotal role in the biogeochemical cycling of carbon (C) in both terrestrial and aquatic environment. The aging of ferrihydrite to more crystalline phases can impact the stability of associated organic C, a process potentially influenced by aluminum (Al) substitution due to its abundance. However, the molecular mechanisms governing the temporal and spatial distribution of SOM during the aging process of Al-substituted Fe oxyhydroxides remain unclear. This study aims to bridge this knowledge gap through a comprehensive approach, utilizing batch experiments, solid characterization techniques, and atomic force microscopy (AFM) based peak-force quantitative nanomechanical mapping (PF-QNM). Batch experiments revealed that humic acid (HA) was released into the aqueous phase during aging, with Al inhibiting this release. Various solid characterization methods collectively suggested that Al hindered the crystalline transformation of ferrihydrite and significantly preserved HA on the surface of newly formed hematite, rather than it being occluded within the interior of the new minerals. Results from 3-Dimensional fluorescence spectroscopy (3D-EEM) and Fourier-transform infrared spectroscopy (FTIR) indicated that the structure of HA remained constant, with the carboxyl-rich and hydroxyl-rich portions of HA fixed at the mineral interface during the aging period. Furthermore, we developed AFM-based PF-QNM to both quantify and visualize the interactions between Fe oxyhydroxides and HA, demonstrating variations in HA affinity among different Fe oxyhydroxides and highlighting the influence of the Al substitution rate.

Vertical distribution of microplastics in urban farmland soils. A case of Mabibo Bonde la Mchicha farm, Dar es Salaam, Tanzania

The rise of microplastics (MPs) is a global concern jeopardizing environmental safety. Initial studies have extensively concentrated on aquatic ecosystems, leaving their presence in terrestrial environments unknown. Thus, this study was carried out to investigate the vertical distribution of MPs in farmland soils of Mabibo Bonde la Mchicha Farm (MBMF), Dar es Salaam. 39 soil samples collected from MBMF were investigated using a Stereomicroscope and QATR-S FTIR. Results herein showed that MPs were found in all soil samples in different depths up to 15 cm deep, ranging from 4.8 to 82.2 items g-1 dry weight (DW). There was a statistically significant difference in MP abundance in depths between 0–5, 5–10 and 10–15 cm layers (P = 0.033) at ὰ = 0.05. The observations were revealed by the observed colors, in which white (36.5 %) was the most frequently observed, followed by blue (21.4 %), brown (20.2 %), black (12.8 %) and red (9 %). Fibers (49.7 %), fragments (32.9 %) and films (17.3 %) were the dominant shapes. Polyethylene (PE) and polypropylene (PP) were the dominant polymers observed constituting 33 % each, polyethylene terephthalate (PET) 11 %, high-density polyethylene (HDPE) 8 %, polyester (PES) 7 %, polyamide (PA) 7 % and polyvinyl chloride (PVC) 1 %. It can be inferred that PE and PP exhibited greater vertical mobility. However, PA and PVC were only observed in the topsoil layer. This study reveals MPs' occurrence and vertical transfer in urban farmland soils of MBMF in Dar es Salaam.

ECR Spotlight – Sara Nørris Christoffersen

ECR Spotlight is a series of interviews with early-career authors from a selection of papers published in Journal of Experimental Biology and aims to promote not only the diversity of early-career researchers (ECRs) working in experimental biology but also the huge variety of animals and physiological systems that are essential for the ‘comparative’ approach. Sara Nørris Christoffersen is an author on ‘ Strong acclimation effect of temperature and humidity on heat tolerance of the Arctic collembolan Megaphorura arctica’, published in JEB. Sara is a PhD student in the lab of Simon Bahrndorff at Aalborg University, Denmark, investigating how climate change affects invertebrates in the Arctic terrestrial environment.

Combined membrane separation and photocatalysis process for the recovery and decomposition of micro/nanoplastics from polyester fabrics

The mismanagement of plastic waste has had a disastrous impact on the aquatic and terrestrial environment This study aims to develop and evaluate an innovative system for treating polyester-polluted water by combining membrane separation and photocatalytic processes. The research objective is to concentrate polyester fibers using membrane technologies and subsequently decompose them through a photocatalytic process using different oxidants, such as hydrogen peroxide and sodium peroxodisulfate.The results, compared in terms of permeate flux, water permeability, fouling index (FI %) and cleaning efficiency (CE %), indicated nanofiltration as the membrane process that allowed not only the complete recovery of fibers from water as with all processes used, but also the almost complete recovery of the initial performance of the membrane used (CA 2 kDa NF) with a cleaning efficiency of 98 % and a low fouling index (16 %).Preliminary photocatalytic tests on some recovered polyester fibers by membrane process showed a decrease in their length and thickness with a weight loss of 13.52 % in 48 h, highlighting the potential of the photocatalytic process to degrade polyester fibers. Furthermore, these results indicated that the photocatalytic process can be tuned to allow the decomposition of polyester avoiding the use of dangerous and costly methods such as the thermal process that can produce toxic by-products. The proposed system, which combines the membrane separation process and the photocatalysis process, could lead to an effective integrated process for the treatment of MPs/NPs from polluted water.

Cytotoxic Pentaketide-Sesquiterpenes from the Marine-Derived Fungus Talaromyces variabilis M22734.

Talaromyces, a filamentous fungus widely distributed across terrestrial and marine environments, can produce a diverse array of natural products, including alkaloids, polyketones, and polyketide-terpenoids. Among these, chrodrimanins represented a typical class of natural products. In this study, we isolated three previously undescribed pentaketide-sesquiterpenes, 8,9-epi-chrodrimanins (1-3), along with eight known compounds (4-11). The structures of compounds 1-3 were elucidated using nuclear magnetic resonance (NMR) and mass spectrometry (MS), while their absolute configurations were determined through X-ray crystallography and electronic circular dichroism (ECD) computations. The biosynthetic pathways of compounds 1-3 initiate with 6-hydroxymellein and involve multiple stages of isoprenylation, cyclization, oxidation, and acetylation. We selected four strains of gastrointestinal cancer cells for activity evaluation. We found that compound 3 selectively inhibited MKN-45, whereas compounds 1 and 2 exhibited no significant inhibitory activity against the four cell lines. These findings suggested that 8,9-epi-chrodrimanins could serve as scaffold compounds for further structural modifications, potentially leading to the development of targeted therapies for gastric cancer.

Application of Photogrammetric Computer Vision and Deep Learning in High-Resolution Underwater Mapping: A Case Study of Shallow-Water Coral Reefs

Abstract. Underwater mapping is vital for engineering applications and scientific research in ocean environments, with coral reefs being a primary focus. Unlike more uniform and predictable terrestrial environments, coral reefs present a unique challenge for 3D reconstruction due to their intricate and irregular structures. Traditional 3D reconstruction methods struggle to accurately capture the nuances of coral reefs. This is primarily because coral reefs exhibit a high degree of spatial heterogeneity, featuring diverse shapes, sizes, and textures. Additionally, the dynamic nature of underwater conditions, such as varying light, water clarity, and movement, further complicates the accurate geometrical estimation of these ecosystems. With the rapid advancement of photogrammetric computer vision and deep learning technologies, there are emerging methods that have potential to enhance the quality of its 3D reconstruction. In this context, this study formulates a coral reef reconstruction workflow that incorporates these cutting-edge technologies. This workflow is divided into two core stages: sparse reconstruction and dense reconstruction. We conduct individual summaries of the relevant research efforts in these stages and outline the available methods. To assess the specific capabilities of these methods, we apply them to real-world coral reef images and conduct a comprehensive evaluation. Additionally, we analyze the strengths and weaknesses of different methods and identify areas for improvement. We believe this study offers valuable references for future research in underwater mapping.

Motion Control of a Hybrid Quadruped-Quadrotor Robot

Multimodal motion capability is an emerging topic in the robotics field, and this paper presents a hybrid robot system maneuvering in both terrestrial and aerial environments. Firstly, a micro quadruped–quadrotor robot with onboard sensing and computing is developed. This robot incorporates both the high mobility of unmanned aerial vehicles and the long endurance of mobile robots on the ground. A coordinated motion control scheme is then exploited for adaptive terrestrial–aerial motion transition. In this scheme, a bio-inspired terrestrial locomotion controller is proposed to generate various quadruped locomotions, and a model-based aerial locomotion controller is proposed to generate various quadrotor configurations. Then, an unified motion controller for the two subsystems which dynamically adjusts crawling and flying motion in a complicated environment is presented. Consequently, several practical trials are conducted to demonstrate the adaptability and the robustness of the proposed system.

Environmental microplastic interact with heavy metal in polluted soil from mine site in the North of Tunisia: Effects on heavy metal accumulation, growth, photosynthetic activities, and biochemical responses of alfalfa plants (Medicago saliva L.)

As emerging persistent pollutants, microplastic (MPs) pollution attracted increasing attention worldwide since it is posing several environmental concerns. MPs interact with heavy metals in soil and may provoke damages on soil properties and ultimately impaired plants and human health. The present study aims to evaluate alfalfa plants (Medicago sativa) response after exposure to heavy metal polluted soils from mine site in the North of Tunisia in presence of environmental microplastic. For that, soils were sampled from two sites of Jebel Ressass mine in addition to a control soil. Plants were exposed to the three soils in presence of two increasing rates of microplastics D1 (1 mg/kg of soil) and D2 (100 mg/kg of soil) for 60 days. After harvest, agronomic parameters, chlorophyll content as well as heavy metal accumulation in plants were analyzed. Furthermore, oxidative status was evaluated in terms of malondialdehyde accumulation (MDA), catalase (CAT) activities and glutathion-S-transferase (GST). Overall, our finding highlights that MPs disrupted agronomic parameters and the photosynthetic activities of alfalfa plants. Additionally, our results revealed that the presence of MPs in polluted soils cause an increase on heavy metal accumulation in alfalfa shoots. Biochemical analyses demonstrated that the combined exposure to MPs and heavy metal induced oxidative stress in alfalfa plants by increasing CAT activity and MDA accumulation. The present investigation highlights the ecological risks of microplastics in terrestrial environment.

Bioponic Cultivation Using Chicken Droppings to Produce Lettuce Plants (Lactuca sativa rz) Uncontaminated by Trace Metals

Anthropogenic activities have denatured aquatic, terrestrial, and aerial environments throughout the world in general, and in Lubumbashi in particular, where market garden soils have become uncultivable for many plants. Thus, bioponics could be an effective means of producing uncontaminated vegetables in soilless cultivation, not only reducing the amount of fertilizer used and limiting contamination of agricultural produce but also achieving higher yields than in open-ground cultivation. The overall objective of this study was to implement a new bioponic technique for producing liquid fertilizer from chicken manure and utilize it in the organic hydroponic cultivation of lettuce (Lactuca sativa var. Lucrecia) installed on floating raft systems. To achieve this, two types of trials were conducted. The first was aimed at determining the quantities of organic matter to be used in the formulation of nutrient solutions. The second trial aimed to determine the optimal nitrogen concentration to be provided for hydroponic plant growth. Mineralization and/or anaerobic digestion of chicken manure were conducted for 7 days in 200 L barrels. For the first trial, nutrient solutions were created from three different concentrations of chicken manure (0.35%, 3.5%, and 7% dry matter—D.M.). These solutions were then used in bioponic rafts where total ammonia nitrogen (TAN) concentrations were fixed at 150 mg/L. For the second trial, D.M. was fixed at 2.5% for each tested modality, but TAN concentrations varied among them (i.e., 60, 90, and 120 mg/L TAN concentration). Modalities with low D.M. concentration (0.35%) and those with low TAN concentration (60 mg/L) resulted in higher yields than bioponic modalities receiving high concentrations of dry matter or TAN, respectively, for trials 1 and 2. Although the reference chemical solutions generate the greatest yields, bioponic systems operating with chicken manure present a good alternative for the cultivation of vegetables in developing countries with heavily contaminated soils. Indeed, bioponics allows for the production of vegetables in large quantities from animal waste, which does not pose health risks for human consumption. Local vegetable species commonly grown in Lubumbashi should be tested under hydroponic conditions.

Highlighting the importance of biodiversity conservation through the Holy Qur'an.

Religious environmentalism relies upon religious texts and leadership to promote effective and long-lasting change for environmental problems, such as responsible use and conservation of natural resources and biodiversity. World religions note the importance of biodiversity and humanity's responsibility in stewarding biodiversity as a member of ecological communities. We reviewed Quranic verses that relate to biodiversity and align with United Nations Sustainable Development Goals (SDGs). The Holy Quran was reviewed in electronic and hard copy formats, and verses related to biodiversity were translated to English and tabulated by Qur'anic chapter, verse, and narrative citation. Twenty-one Qur'anic verses were identified that addressed biodiversity. Scriptures were divided into 5 groups that addressed provision of resources, governance or stewardship of resources, nature as a teacher, and human life in nature's communities or described creation of biodiversity. Qur'anic verses were aligned with 4 SDGs (goals 12-15), which address sustainable consumption of natural resources, global climate change, life in marine environments, and life in terrestrial environments, including freshwater ecosystems. This alignment demonstrates the interconnectedness of life, that conservation of biodiversity is referenced in the Quran, and how positive management of natural recourses can be beneficial to Muslim communities on local, national, and global scales. Positive movement toward ecofriendly practices, sound environmental resource use and management, biodiversity conservation, and governmental policies on conservation can be promoted through scriptures from the Holy Qur'an.

Microfibers in the Diet of a Highly Aerial Bird, the Common Swift Apus apus.

Microplastic pollution is a pervasive global issue affecting various ecosystems. Despite the escalating production and well-documented contamination in both aquatic and terrestrial environments, the research focused on airborne microplastics and their interaction with terrestrial birds remains limited. In this study, we collected fecal sacs from Common swifts (Apus apus) to investigate their diet and to evaluate the potential ingestion of microplastics by both adults and nestlings. The diet was mainly composed of Hymenoptera and Coleoptera and did not differ among sexes and age classes. The 33% of nestlings' and 52% of adults' fecal sacs contained anthropogenic items, the totality of which was in the shape form of fibers. The 19.4% of the anthropogenic items were chemically characterized as microplastics, either polyethylene terephthalate (PET; two microfibers) or cellophane (four microfibers). Airborne anthropogenic items, including microplastic, might be passively ingested during the Common swift aerial feeding. In addition, our findings suggest that these ingested microparticles have the potential to be transferred to the offspring through food. While further research is essential to elucidate the pathways of microplastic ingestion, our results reinforce the evidence of the transfer of anthropogenic items from the atmosphere to the biota.

Professor John Roderick Cameron's Influence on Radiation Safety in Terrestrial and Space Environments.

Professor John Roderick Cameron (1922-2005) stands out as a trailblazer in the field of medical physics, whose innovative work has deeply influenced radiation protection and the broader medical radiation field through sound technical judgment and insight. Best known for inventing the bone densitometry device, his pioneering efforts have reshaped modern medical practices far beyond his initial breakthroughs. Cameron's explorations extended into the realms of space biomedical science and models of terrestrial radiation, areas where his insights continue to resonate today. As the Emeritus Professor of Medical Physics at the University of Wisconsin-Madison and a founding member of the American Association of Physicists in Medicine, Cameron laid crucial groundwork for safety standards in environments with high natural radiation levels. His leadership was instrumental in advancing thermoluminescence dosimetry, radiation measurement, and image quality assurance, driving progress in both academia and clinical practices. Moreover, through establishing Medical Physics Publishing, Cameron played a pivotal role in spreading vital research and educational materials across the fields of health physics and medical physics. This commentary reflects on Cameron's far-reaching contributions, highlighting his critical work in space radiation research and terrestrial radiation models-key to the future of interplanetary travel and potential human settlement on planets like Mars. His research in areas of high background radiation, like Ramsar, Iran, has been fundamental in developing strategies for biological protection in space, which are essential for ensuring astronaut safety during long-duration space missions. We honor Professor Cameron's profound legacy, celebrating his visionary spirit and the lasting impact of his contributions on generations of scientists in radiation science.

A Review on Toxicity and Degradation of Ethidium Bromide (EtBr)

Ethidium bromide (EtBr) serves as an interpolating agent utilized for its fluorescent properties in gel electrophoresis, aiding in the detection of various DNA fragments. However, its usage has been associated with DNA mutations, inhibition of mitochondrial protein synthesis and other alterations, particularly at high concentrations. Due to its remarkable stability in the environment and propensity to degrade into mutagenic compounds, especially when exposed to bleaching agents, there are significant concerns regarding its widespread use. Given the potential toxic and mutagenic effects of EtBr and the possibility of its entry into the food chain, it becomes crucial to monitor its concentration at emission sources across different ecosystems, including aquatic, terrestrial, and plant environments. Improper disposal of EtBr poses substantial risks, including the induction of mutations and cancer. Various disposal methods have been explored, such as phytoremediation and employing bacteria capable of degrading this chemical. Proper management of EtBr disposal is paramount to mitigate its harmful impact on the environment and living organisms.

Out of the frying pan into the fire: Predicted warming in alpine streams suggests hidden consequences for aquatic ectotherms.

Thermal regimes of aquatic ecosystems are predicted to change as climate warming progresses over the next century, with high-latitude and high-elevation regions predicted to be particularly impacted. Here, we have modelled alpine stream water temperatures from air temperature data and used future predicted air temperature trajectories (representative concentration pathway [rcp] 4.5 and 8.5) to predict future water temperatures. Modelled stream water temperatures have been used to calculate cumulative degree days (CDDs) under current and future climate conditions. These calculations show that degree days will accumulate more rapidly under the future climate scenarios, and with a stronger effect for higher CDD values (e.g., rcp 4.5: 18-28 days earlier [CDD = 500]; 42-55 days earlier [CDD = 2000]). Changes to the time to achieve specific CDDs may have profound and unexpected consequences for alpine ecosystems. Our calculations show that while the effect of increased CDDs may be relatively small for organisms that emerge in spring-summer, the effects for organisms emerging in late summer-autumn may be substantial. For these organisms, the air temperatures experienced upon emergence could reach 9°C (rcp 4.5) or 12°C (rcp 8.5) higher than under current climate conditions, likely impacting on the metabolism of adults, the availability of resources, including food and suitable oviposition habitat, and reproductive success. Given that the movement of aquatic fauna to the terrestrial environment represents an important flux of energy and nutrients, differential changes in the time periods to achieve CDDs for aquatic and terrestrial fauna may de-couple existing predator-prey interactions.

Actinobacteria diversity associated with marine sediments and a wetland system, Agulhas-South Africa

BackgroundSouth Africa is known for its great biodiversity. The Agulhas Plain represents one such unique environment where low-gradient topography has resulted in extensive wetland formation. It is fed by two major river systems, bringing in brackish, alkaline water. It has been exposed to major marine transgression and regression events, and harbours great Fynbos diversity as well as a Mediterranean-type climate, thereby creating unique ecosystems. It is therefore surprising that little is known about the bacterial diversity associated with the Agulhas Plain and associated marine ecosystems.MethodsIn this study, we focused on the actinobacterial diversity (Phylum Actinomycetota) associated with an emerging peatland on the Agulhas Plain (SF; Areas 1–3) and a marine site (ANP; Ocean, Rocky, Dry) located 10 km away from SF. A combined metataxanomics and isolation approach was taken to evaluate the actinobacterial diversity of the sampling sites and to determine the effect of environmental physicochemical parameters on these populations. Various genome analyses were performed on an Sva0096 marine bin to gain insight into its ecological role.ResultsMetataxanomics showed that the two sites shared defined major taxa, including Blastococcus, Geodermatophilus, Microbacterium, Mycobacterium, Nocardioides, Streptomyces, and the Sva0996 marine group. Analysis of the biosynthetic potential of an Sva0996 marine bin134 (obtained from GenBank) provided insights into the potential ecological role of this group of bacteria in both the marine and terrestrial environments. Higher actinobacterial diversity (Shannon index > 5) was observed for Areas 2 and 3 (SF), as well as the ANP Dry samples. The actinobacterial population composition was found to be driven by salinity, pH, Mn, and Ca, with certain areas of SF exhibiting similar (and even higher) salinity (SF: 70–100 Ω vs. ANP: 100–160 Ω) and lower pH levels (SF: 6.3-8.0 vs. ANP: 8.6–8.9) to that of the marine environment.ConclusionThis snapshot study has provided some insights into the actinobacterial diversity of the two sites studied. Analysis of an Sva0096 marine bin134 provided further insights into the potential ability of the Sva0096 marine group to survive in a unique terrestrial environment that is periodically exposed to environmental pressures that mimic the marine environment.

Seabird transported contaminants are dispersed in island ecosystems

Seabirds are long-range transporters of nutrients and contaminants, linking marine feeding areas with terrestrial breeding and roosting sites. By depositing nutrient-rich guano, which acts as a fertiliser, seabirds can substantially influence the terrestrial environment in which they reside. However, increasing pollution of the marine environment has resulted in guano becoming similarly polluted. Here, we determined metal and metalloid concentrations (As, Cd, Cr, Cu, Hg, Pb) in Flesh-footed Shearwater (Ardenna carneipes) guano, soil, terrestrial flora, and primary consumers and used an ecological approach to assess whether the trace elements in guano were bioaccumulating and contaminating the surrounding environment. Concentrations in guano were higher than those of other Procellariiformes documented in the literature, which may be influenced by the high amounts of plastics that this species of shearwater ingests. Soil samples from shearwater colonies had significantly higher concentrations of all metals, except for Pb, than soils from control sites and formerly occupied areas. Concentrations in terrestrial primary producers and primary consumers were not as marked, and for many contaminants there was no significant difference observed across levels of ornithogenic input. We conclude that Flesh-footed Shearwaters are transporters of marine derived contaminants to the Lord Howe Island terrestrial environment.