Hasil untuk "Natural history (General)"

Joachim Larsen Marthinsen, Elin Kjørsvik, Paul Whatmore et al.

Atlantic cod (Gadus morhua) stores excess dietary lipids as triacylglycerol (TAG) in the liver, but substantial accumulation emerges only during the late larval stage, characterized by a sharp increase in hepatic vacuolization (4-35%) between 45 and 61 days post-hatching (dph). To investigate mechanisms underlying this transition, we examined the ontogeny of bile and lipid metabolic pathways in cod larvae (2–60 dph) using RNA sequencing of whole-body larvae and quantitative real-time PCR of digestive tissues for key genes involved in dietary lipid processing. We further tested transcriptomic effects of two dietary phospholipid (PL) levels (ca. 7 and 6% dry matter) with or without bile salt (BS) supplementation (0.04% dry matter) during co-feeding (17–34 dph) and through 60 dph. Ontogenetic expression patterns indicated that hepatic lipid accumulation is not constrained by the capacity for lipid digestion, synthesis or transport. Instead, the onset of hepatic lipid deposition coincided with pronounced upregulation of the TAG-synthesizing enzyme dgat2 and the lipid droplet-stabilizing protein plin2 in digestive tissues, with plin2 also increasing sharply in whole-body larvae. Dietary PL level and BS supplementation elicited only modest and inconsistent transcriptional responses, suggesting limited dietary modulation of the examined pathways under the tested conditions. We propose dgat2 and plin2 as candidate markers of liver development in cod larvae and emphasize the need for multi-omics approaches to clarify the mechanisms regulating hepatic lipid storage.

Shaochun Xu, Shaochun Xu, Shaochun Xu et al.

Under accelerating coastal eutrophication, disentangling the relative roles of light limitation and nitrogen enrichment is essential for diagnosing seagrass decline. We conducted a fully crossed light × ammonium experiment using intact Zostera marina cores from Guzhenkou Bay (4 irradiance levels: 180, 90.6, 17, 0 μmol photons m-2 s-1; 4 NH4Cl levels: 0, 25, 50, 100 μmol L-1; 5 weeks; 16 units; no within-cell replication). Across traits, irradiance—not NH4Cl within the tested range—governed responses at the level of dominant main effects. Shading sharply reduced shoot density, above- and below-ground biomass (AGB, BGB) and Fv/Fm, with near-complete collapse at darkness. Biomass turnover accelerated under shading (higher above-ground shedding, below-ground mass loss), and below-ground carbon content declined, together indicating a shift from carbon accrual to expenditure. By contrast, NH4Cl enrichment showed minimal main effects on morphology, pigments, Fv/Fm, or antioxidant enzymes, although tissue δ15N decreased with NH4Cl addition, evidencing ammonium assimilation. Antioxidant responses were variable (POD increased with reduced irradiance; SOD, CAT, GSH-Px inconsistent), while MDA did not increase under shading and was occasionally higher under high light, consistent with lower photo-oxidative load at low irradiance. Leaf and rhizome δ13C showed no significant treatment effects and only a weak, non-significant tendency toward less negative values under severe shading. Collectively, the trait suite diagnoses light-driven carbon limitation as the proximal stressor, with nitrogen effects contingent on concentration and context. We recommend tiered monitoring that couples rapid photophysiology (Fv/Fm) with structural (shoot density, AGB/BGB) and integrative biogeochemical indicators (below-ground C; δ-isotopes), and management focused on water clarity to meet species-specific light requirements.

Max Kasparek, Marta Bonforte, Roberto Catania

Gynandromorphism is a condition in which both male and female morphological characteristics are present in a single specimen. This phenomenon has been well-documented in Apoidea, but with only a few cases in megachilid bees. Here, we described two new instances of gynandromorphism in wool carder bees (Hymenoptera: Megachilidae: Anthidiini), including the first record in the genus Rhodanthidium. The studied cases include single specimens of Anthidium punctatum Latreille from Bulgaria and Rhodanthidium siculum (Spinola) from Italy. To date, gynandromorphism in Anthidiini has been observed only in nine species of the genera Anthidiellum Cockerell, Anthidium Fabricius, Dianthidium Cockerell, Rhodanthidium Isensee, and Trachusa Panzer, underscoring the rarity of this phenomenon in this tribe.

Yuye Zou, Xiaohui Wang, Qiang Zhang

This paper analyzes 441 of China's green port policies using text mining and quantitative evaluation methods to promote the sustainable development of China’s ports and accelerate the achievement of the “dual carbon” goal. The study first reviews the evolution of these policies, categorizing them into three stages: the embryonic stage, the startup stage, and the development stage. High-frequency words were extracted for each stage, followed by dimensionality reduction using Principal Component Analysis (PCA) and clustering analysis to classify the policies. The Latent Dirichlet Allocation (LDA) topic model was then applied to identify the main policy themes, and a Policy Modeling Consistency (PMC) index model was developed. The study evaluated 19 representative policies using cosine similarity and correlation coefficients. The analysis revealed several key issues: (1) the entity responsible for policy issuance is singular, with insufficient interdepartmental collaboration; (2) short-term policies are lacking, with weak responsiveness; (3) policies targeting shipping companies are underdeveloped; and (4) there is an imbalance in the use of policy instruments, with a focus on mandatory and hybrid tools. Based on these findings, the paper proposes several suggestions for improving green port development policies.

Masoud Mohammed Aloufi, Abudlaziz Khalaf Al-jabri, Muna Abdullah Al-Mazroui et al.

Abed El Rahman Hassoun, Toste Tanhua, Emma Heslop et al.

The European Ocean Observing Community (EOOC) integrates inputs from diverse entities dedicated to comprehensively monitoring and forecasting oceanic phenomena in European Seas. With increasing climate and anthropogenic pressures, the urgency of ensuring the EOOC’s preparedness to observe Essential Ocean Variables (EOVs) is evident. This paper advocates for the adoption of a scoring approach designed to evaluate the readiness of the EOOC in observing and forecasting key ocean phenomena. The proposed scoring methodology can be applied at both European and potentially regional and/or national levels, and emerges as a transformative tool for scrutinizing the EOOC’s capability to predict and monitor key ocean phenomena. Our findings, based on the application of the scoring approach, suggest that while the community demonstrates commendable readiness levels for certain oceanic phenomena, 83% remain in developing stages, oscillating between “Idea” and “Trial” readiness levels. A closer examination exposes critical shortages predominantly in the coordination and observational facets (Process), and data management and information products (Output). The implications of these identified gaps reach far beyond academic realms, profoundly affecting diverse sectors and societal resilience (e.g., energy sector). The suggested scoring approach serves as a clear call for strategic investments and heightened support for the European observing community. By adopting a regular and systematic scoring methodology, we not only measure progress at present but also pave the way for a resilient and future-ready EOOC.

Li Zhou, Mengna Li, Mengna Li et al.

IntroductionMarine metal contamination caused by deep-sea mining activities has elicited great concern from both social and scientific communities. Among the various metals deep-sea organisms might encounter, cadmium (Cd) is a widely detected metal that in very small amounts is nonetheless capable of severe toxicity. Yet due to both remoteness and technical challenges, insights into the effects of metal exposure resulting from mining activities upon deep-sea organisms are limited.MethodsHere, we investigated Cd’s toxicological effects on deep-sea mussels of Gigantidas platifrons exposed to 100 or 1000 g/L of Cd for 7 days; an integrated approach was used that incorporated proteomics and metabolomics along with traditional approaches (metal concentrations, metal subcellular distribution, and anti-oxidative and immune-related biochemical indexes).Results and DiscussionResults showed that Cd exposure caused significant Cd’s accumulation in mussel gills and redistribution of Cd among subcellular compartments, with cellular debris being the primary binding site. Although anti-oxidative enzymes activities (superoxide dismutase and catalase) were not significantly altered in mussel gills of both exposed groups, the markedly increased level of glutathione S-transferase detected via proteomic technique clearly evinced that deep-sea mussels suffered from oxidative stress under Cd exposure. Besides, altered activities of acid phosphatase and alkaline phosphatase assayed by traditional methods along with the predominant presence of largely altered immune-related proteins detected by proteomic data strongly revealed an immune response of deep-sea mussels elicited by Cd. In addition, results of proteomics combined with those of non-targeted metabolomics demonstrated that Cd could exert toxicity by disrupting cytoskeleton structure, ion homeostasis, and primary metabolisms of energy, lipid, and nucleotide in deep-sea mussels. As demonstrated in this study, proteomics and metabolomics can be used in tandem to provide valuable insights into the molecular mechanisms of deep-sea organisms’ response to Cd exposure and for helping to discover potential biomarkers for application during deep-sea mining assessments.

Nicolás M. Rendtorff

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Mahmoud S. Gewaily, Mustafa Shukry, Marwa F. Abdel-Kader et al.

Aeromonas hydrophila infection is one of the major diseases that cause inflammation and immunodepression in aquatic animals. Likewise, waterborne toxins are known for their negative impact on the immunity and antioxidant responses of aquatic organisms. In this study, Lactobacillus plantarum (LP20) was incorporated in Nile tilapia, Oreochromis niloticus, diets (50 mg/kg) to investigate its role in the antioxidant capacity, immunity, and anti-inflammation induced by deltamethrin (DLM) toxicity (96-h LC50 was 14.9 μg/L) and A. hydrophila (LD50, 2 × 108 CFU/ml). One hundred and twenty healthy fish with an initial weight of 28.21 ± 1.34 g were allotted in 12 glass aquaria (60 L) and divided randomly into four groups (triplicates, 10 fish per aquarium). The control fish neither received LP20 nor were exposed to DLM. The second group of fish was fed the control diet and subjected to DLM (DLM group). The third group of fish was provided with LP20 without DLM toxicity (LP20 group), and the fourth group of fish was fed LP20 and subjected to DLM (DLM + LP20 group). After 30 days, fish were intraperitoneally injected with A. hydrophila. Ten days post infection, the survival rate was lower in fish exposed to DLM than those exposed to LP20. Further, fish fed on LP20 had elevated serum total protein (sTP), albumin (ALB), globulin (GLB), phagocytic index (PI), phagocytic (PA), and lysozyme activities (LZM), but they had lower urea, uric acid bilirubin, creatinine, glucose, aspartate aminotransferase (AST), alkaline phosphatase (ALP), and alanine aminotransferase (ALT) activities after 24 h, 48 h, and 1 week post A. hydrophila challenge. However, fish exposed to DLM had lower sTP, ALB, GLB and higher urea, uric acid, bilirubin, creatinine, glucose, ALT, AST, and ALP after 24 h, 48 h, and 1 week post A. hydrophila challenge. Markedly, after the A. hydrophila challenge, fish exposed to DLM + LP20 displayed upregulated levels of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) genes. The transcription of interferon gamma (IFN-γ), interleukin 12 (IL-12), and tumor necrosis factor alpha (TNF-α) was upregulated in DLM and DLM + LP20 groups. Fish exposed to DLM downregulated interleukin 8 (IL-8) gene expression after A. hydrophila challenge. Further, fish displayed upregulation of heat shock protein 70 (HSP70) gene expression after DLM toxicity. Besides, fish exposed to DLM toxicity and A. hydrophila infection had severe inflammatory features in the liver, spleen, gills, and intestine, while dietary LP20 relieved the inflammatory features. In summary, dietary LP20 relieves Nile tilapia from oxidative stress, immunosuppression, and inflammation induced by DLM and A. hydrophila infection.

Allison J. Shultz, Benjamin J. Adams, Kayce C. Bell et al.

Abstract Urban environments are among the fastest changing habitats on the planet, and this change has evolutionary implications for the organisms inhabiting them. Herein, we demonstrate that natural history collections are critical resources for urban evolution studies. The specimens housed in these collections provide great potential for diverse types of urban evolution research, and strategic deposition of specimens and other materials from contemporary studies will determine the resources and research questions available to future urban evolutionary biologists. As natural history collections are windows into the past, they provide a crucial historical timescale for urban evolution research. While the importance of museum collections for research is generally appreciated, their utility in the study of urban evolution has not been explicitly evaluated. Here, we: (a) demonstrate that museum collections can greatly enhance urban evolution studies, (b) review patterns of specimen use and deposition in the urban evolution literature, (c) analyze how urban versus rural and native versus nonnative vertebrate species are being deposited in museum collections, and (d) make recommendations to researchers, museum professionals, scientific journal editors, funding agencies, permitting agencies, and professional societies to improve archiving policies. Our analyses of recent urban evolution studies reveal that museum specimens can be used for diverse research questions, but they are used infrequently. Further, although nearly all studies we analyzed generated resources that could be deposited in natural history collections (e.g., collected specimens), a minority (12%) of studies actually did so. Depositing such resources in collections is crucial to allow the scientific community to verify, replicate, and/or re‐visit prior research. Therefore, to ensure that adequate museum resources are available for future urban evolutionary biology research, the research community—from practicing biologists to funding agencies and professional societies—must make adjustments that prioritize the collection and deposition of urban specimens.

Roland Proud, Camille Le Guen, Richard B. Sherley et al.

King penguins (Aptenodytes patagonicus) are an iconic Southern Ocean species, but the prey distributions that underpin their at-sea foraging tracks and diving behaviour remain unclear. We conducted simultaneous acoustic surveys off South Georgia and tracking of king penguins breeding ashore there in Austral summer 2017 to gain insight into habitat use and foraging behaviour. Acoustic surveys revealed ubiquitous deep scattering layers (DSLs; acoustically detected layers of fish and other micronekton that inhabit the mesopelagic zone) at c. 500 m and shallower ephemeral fish schools. Based on DNA extracted from penguin faecal samples, these schools were likely comprised of lanternfish (an important component of king penguin diets), icefish (Channichthyidae spp.) and painted noties (Lepidonotothen larseni). Penguins did not dive as deep as DSLs, but their prey-encounter depth-distributions, as revealed by biologging, overlapped at fine scale (10s of m) with depths of acoustically detected fish schools. We used neural networks to predict local scale (10 km) fish echo intensity and depth distribution at penguin dive locations based on environmental correlates, and developed models of habitat use. Habitat modelling revealed that king penguins preferentially foraged at locations predicted to have shallow and dense (high acoustic energy) fish schools associated with shallow and dense DSLs. These associations could be used to predict the distribution of king penguins from other colonies at South Georgia for which no tracking data are available, and to identify areas of potential ecological significance within the South Georgia and the South Sandwich Islands marine protected area.

Julia R.S.A. Mangueira, Leandro T.A. Vieira, Thaís N. Azevedo et al.

Different types of matrices can perform different disturbance regimes over remnant forests, which can ultimately affect plant diversity. To address these issues, we studied 60 plots in forest remnants embedded within sugarcane plantations and pasturelands in the Atlantic Forest of Southeastern Brazil. Our objectives were to evaluate general patterns of plant diversity and to assess the influence of landscape structure and dynamics on plant richness and diversity. We recorded 297 species in two strata. (DBH superior stratum ≥ 4.8 cm > inferior stratum). Overall, diversity of the inferior stratum was higher in pastureland forest remnants than in sugarcane matrices. In the superior stratum, time since abandonment represented a greater influence. Considering the partition of diversity, more than 40% of total diversity was due to the alpha component alone in all cases, but it was significantly lower than expected. Beta components among forest remnants, landscapes and matrices were higher than expected for both strata, whether together or separately. Habitat heterogeneity showed a higher contribution to the total floristic diversity, but among remnants this contribution was even more significant. Forest remnants in pasturelands had a more dynamic land use history and parameters of landscape dynamics were more related to plant diversity. For remnants in the sugarcane matrices, species richness and composition were explained by landscape structure. Our results highlight that there is an important plant community diffused in the forest remnants of human-modified landscapes. Therefore, conserving the majority of remnants and restoring degraded ones must be a key conservation strategy.

Gabriel A. Juma, Gabriel A. Juma, Adiel M. Magana et al.

Seagrass and associated blue carbon ecosystems are important carbon sinks, and hence understanding their spatial and temporal variability is vital in appreciating their potential roles in climate change mitigation and adaptation. The Indo-Pacific region has the highest seagrass biodiversity, yet little focus has been made to compare seagrass habitat extent and carbon dynamics with their temperate counterparts. The present study assessed habitat characteristics and seagrass species distribution, diversity, and carbon storage in Eastern (marine) and Western (estuarine) mangrove-fringed creeks of Gazi Bay, Kenya. Data on species composition, canopy cover, biomass, and sediment organic carbon were collected in 80 plots of 0.25 × 0.25 m laid along transects established perpendicular to the waterline. Five species formation, viz., Thalassia hemprichii, Cymodocea rotundata, Cymodocea serrulata, Enhalus acoroides, and Thalassidendron ciliatum, were encountered as either single or mixed stands. There was a significant difference in total seagrass biomass between creeks (p < 0.01), with the Eastern creek recording a mean of 10.2 ± 0.6 Mg C ha–1 while the Western creek recording 4.3 ± 0.3 Mg C ha–1. In addition, sediment carbon to 1-m depth varied significantly (p < 0.01) between species in the two creeks and ranged from 98 to 302 Mg C ha–1, with the Eastern and Western creeks recording means of 258 ± 90 and 107 ± 21 Mg C ha–1, respectively. The total carbon stock from 50 ha of seagrasses in the Eastern creek was 13,420 Mg C, whereas in the 70 ha of the Western creek it was 7,769 Mg C. The study shows that seagrass community attributes such as species composition and productivity can vary dramatically over a small spatial extent due to differences in biophysical conditions and caution estimations of site-specific carbon stocks using generalized global values.

Rachelle K. Gould, Kimberly J. Coleman, Daniel H. Krymkowski et al.

Abstract This article explores the “broader impacts” of research related to biodiversity conservation. We analyze a sample of abstracts of proposals funded by the United States National Science Foundation's (NSF) Biology (BIO) and Social, Behavioral, and Economic Sciences (SBE) directorates. The analysis, based on the NSF conceptualization of broader impacts, identified 21 important types of broader impacts mentioned in the abstracts. Our results show that the vast majority of NSF grant recipients propose a small range of broader impacts, and that predictable differences exist in the types of broader impacts that are more and less common for conservation‐related work in the biological and social sciences. BIO abstracts contained proportionally fewer mentions of equity, case studies, international links, and workshops for conservation practitioners. SBE abstracts contained proportionally fewer mentions of dissemination to local communities, data sharing, websites, and curriculum. We discuss multiple forms of broader impact (e.g., process‐based impacts vs. sharing of results), and then, like the abstracts we analyzed, focus on communication and engagement mechanisms. In order to aid future efforts, we provide examples of unusual and particularly creative approaches that conservation scientists can use to enhance the broader impacts of their work.

Angel Borja, Joxe Mikel Garmendia, Iratxe Menchaca et al.

Substantial progress has been made in assessing marine health in an integrative way. However, managers are still reluctant in undertaking such assessments, because: (i) lack of indicators; (ii) absence of targets; (iii) difficulty of aggregating indicators from different ecosystem components, habitats, and areas; (iv) absence of criteria on the number of indicators to be used; (v) discussion on the use of “one-out, all-out” (OOAO) principle in aggregating; and (vi) lack of traceability when integrating data. Our objective was, using open access databases with indicators across all the European seas with agreed targets, to demonstrate if the Nested Environmental status Assessment Tool (NEAT), can be used at the European scale, serving to managers and policy-makers as a tool to assess the environmental status under the Marine Strategy Framework Directive (MSFD). We have used MSFD Descriptor D3 (commercial fish) from 341 stocks, 119 species and two indicators from each of them (years 2013–2015); D5 (eutrophication) with 90th percentile of Chlorophyll-a (years 2009–2014); and D8 (contaminants), with Anthracene, Fluoranthene, Naphthalene, Cadmium, Nickel, and Lead as indicators (years 2009–2013). We have calculated the environmental status for each European subdivision, subregion, and regional sea, nested at different levels. The analyses include weighting and no-weighting by each assessment area; for ecosystem component (water column, phytoplankton, fish, crustaceans, and molluscs); descriptor (three), and habitat (pelagic, demersal/benthic), with the confidence value of the status. A sensitivity analysis was undertaken to determine a minimum number of indicators to include for a robust assessment. We demonstrated that using NEAT in assessing the status of large marine areas, by aggregating indicators, ecosystem components and descriptors, at different spatial scales, can remove at least four out of the six barriers that managers and policy-makers confront when undertaking such assessments. This can be done by using open-access databases and already established targets. Aggregating indicators of different origin is possible. Around 40 indicators seem to be enough to obtain robust assessments. It is better to integrate the assessment items using an ecosystem-based approach, rather than using the OOAO principle. Using NEAT, this approach supports identifying the problematic environmental issues needing management attention and measures.

Rachel M. Wilson, Reny B. Tyson, James A. Nelson et al.

Two groups of common bottlenose dolphins (Tursiops truncatus) have been identified within St. George Sound, Florida, USA: high site-fidelity individuals (HSF) which are individuals sighted multiple times in the region (i.e., ≥2 months, ≥2 seasons, and ≥2 years), and low site-fidelity individuals (LSF), which are individuals sighted fewer than 2 months, in 2 different seasons among 2 different years. Our goal was to determine whether differences in foraging behaviors were correlated with differences in sighting frequency and overall usage of St. George Sound by the two groups. We used carbon, nitrogen, and sulfur stable isotopes and niche hypervolume metrics to model the foodweb of St. George Sound. Mixing model results indicated that croaker, mojarra, pigfish, pinfish, and silverperch were the most important prey items for dolphins. The hypervolume metrics demonstrate niche partitioning between HSFs and LSFs, with the HSFs relying more heavily on pinfish, pigfish, and mojarra, while the LSFs relied more on silverperch. Plankton, benthic diatoms, seagrass, and epiphytes all contributed to secondary production within St. George Sound. This diversity of source utilization by seagrass-associated consumers supported by a high rate of total production likely sustains high secondary productivity despite the potential for competition in this system. Zooplankton was the most important basal source to the system, followed by seagrass and benthic primary production (as indicated by a sanddollar proxy). The reliance of dolphins on seagrass-dependent prey indicates that alteration of seagrass habitat would significantly impact the dolphin community foraging in St. George Sound and suggests that preservation of seagrass habitat is an important component of an effective management strategy for dolphin populations in the region.

João Augusto Alves Meira-Neto, Andreza Viana Neri

The Brazilian Mining Lobby uses Congress to weaken the Mining Code. In November 2015, the Fundão Dam, which was retaining a reservoir of mining waste, collapsed in Minas Gerais State, causing the largest socio-environmental disaster in Brazilian history. We propose actions for the restoration of the ecosystems of the Doce River Basin based on maps of taxonomic, functional and phylogenetic diversity of plants as potential providers of vital ecosystem services. To achieve these goals, a databank will be established by compiling existing databases on the vegetation of the Doce River Basin. We propose mapping biodiversity potential for ecological restoration and the conservation of ecosystem functions and services. Such mapping will facilitate the identification and establishment of ecosystem services reserves. Only with this effort will actions to restore and maintain the ecosystem services of the basin be achievable. The same effort can be applied to other impacted river basins such as those of the São Francisco and Amazonas rivers.

D. S. Hardy

A New Aloe From South West Africa

A. A. Obermeyer

A NEW SPECIES OF  STRUMARIA

Rodolfo Hauthal

En la excursión efectuada con el señor Director del Museo, en el año último, en la región del Noroeste Argentino, hice la interesante observación de que en toda aquella región se presentan indicios que demuestran la antigua existencia de ventisqueros. (Véanse mis informes en dos apéndices de «Una excursión al Noroeste Argentino, por Francisco P. Moreno», actualmente en publicación.) Sobre todo, estos indicios son muy visibles y abundantes en el macizo del Aconquija (Catamarca), y en dicho punto observé también que no data de mucho tiempo (en sentido geológico), la existencia y retiro de los ventisqueros. Llevado, por mis trabajos de geólogo, á la Cordillera Mendocina, me llamó allí vivamente la atención de que los ventisqueros actuales indicasen con toda claridad que no solo tenían hasta ahora poco tiempo una extensión mucho mayor, sino que hoy pierden de su volumen y que se retiran   con gran prontitud.