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1.
Sci Total Environ ; 954: 175578, 2024 Sep 11.
Artigo em Inglês | MEDLINE | ID: mdl-39270871

RESUMO

Harmful algal blooms have been documented in the Moroccan Western Mediterranean region since 1993, primarily associated with the presence of paralytic shellfish toxins (PSTs) produced by the dinoflagellate Gymnodinium catenatum. The proliferation of this neurotoxic species has led to recurring bans on the harvesting of molluscs, resulting in significant socio-economic repercussions and threats to human health. In the present study, we examine the dynamics of G. catenatum and mollusc PST contamination patterns over a 20-year period (2002-2021) in two distinct marine ecosystems: M'diq Bay and the Oued Laou Estuary. For the PST contamination, we considered two commercially important shellfish species: the smooth clam, Callista Chione, and the cockle, Acanthocardia tuberculata. The highest G. catenatum abundances were consistently observed from November to February in both sites. Our data revealed inter-annual variations in G. catenatum abundance, peaking at 91,840 cells.L-1 in November 2011. PST contamination levels in A. tuberculata were significantly higher than those observed in C. chione. Furthermore, we identified a significant correlation (Pearson, P-value <0.05) between PST contamination of smooth clams and the abundance of G. catenatum. The contamination of A. tuberculata by PSTs reached very high levels, with up to 13,500 µg STX di-HCl eq. kg-1 of shellfish meat, exceeding the established safety thresholds by 16-fold. Additionally, there has been an increase in the prevalence and incidence of PSTs over the years. Notably, we observed a substantial increase in G. catenatum blooms and PST events in the Western Mediterranean during the last decade (2010-2021). The examined data suggest that rainfall could play a pivotal role in G. catenatum bloom dynamics by enriching marine waters with nutrients. The statistical model selection approaches indicated that nutrient concentrations (i.e., nitrate and phosphorus) were the most significant parameters for G. catenatum blooms in the studied area.

2.
Biol Trace Elem Res ; 2024 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-39316266

RESUMO

The aim of this study was to determine the levels of essential trace elements copper, zinc, manganese, and nickel in two size groups of mussels, Mytilus galloprovincialis, sampled from three sites along the Algerian coast with different levels of pollution. The results of this work are very interesting for determining the effect of mussel size on the variation of contaminant levels in environmental monitoring studies. Thirty individuals from 2 size groups, less than 4-cm and more than 4-cm shell length, were collected over 4 seasons at each site studied. The samples were dissected, and copper, zinc, manganese, and nickel were measured in the whole soft tissues by inductively coupled plasma mass spectrometry (ICP-MS). The maximum concentrations of copper, zinc, manganese, and nickel expressed in mg/kg dry weight at the three sites were 54.01, 146.25, 20.69, and 8.85, respectively. A clear distribution pattern of the studied elements was observed in the two size classes. In fact, significantly higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm. Significantly, higher concentrations (P < 0.05) were found in individuals with a shell length of less than 4 cm due to their high filtration and low excretion activities compared to long individuals. In addition, metal pollution index (MPI) values were higher in small bivalve individuals. The trace element contents found in the mussel samples of the present study showed large spatial and temporal variations among the different sites studied, highlighting the typical exposure of marine sites to different marine pollutants. Notably, elevated concentrations of copper were observed in the port of Zemmouri, likely due to port activities. Conversely, the highest levels of manganese and nickel were recorded at Boudouaou El Bahri, potentially attributable to the use of fertilisers by agricultural activities. Some shellfish samples had exceeded the permissible concentration levels of copper and manganese, thereby posing a danger to bivalve consumers.

3.
Sci Total Environ ; : 176455, 2024 Sep 22.
Artigo em Inglês | MEDLINE | ID: mdl-39317258

RESUMO

River discharge into the sea and its implications on the environmental setting and fauna in the nearshore represent the intricate interactions among the atmosphere, hydrosphere, lithosphere, and biosphere. This study, based on in-situ and satellite data, presents how spatially varying river discharge laden with suspended sediments structure the hydrography and the nearshore benthic environment over a 590 km southwest (Kerala) coast of India. The 41 rivers that discharge along the Kerala coast are monsoon-driven; they are small but swift and cumulatively supply huge amounts of freshwater and suspended sediments into the Southeastern Arabian Sea (SEAS) during the Southwest Monsoon (SWM) when around 70 % (1925 mm) of the yearly rainfall occurs. These rivers are distributed unevenly along the coastline, with twenty-four of them discharging in the northern region (10.9-12.5°N), nine in the central (9.2-10.9°N), and eight in the south (8-9.2°N). During the SWM, plumes of low salinity (<32) with high clay content were widespread in the northern and central regions of the study area due to heavy river discharge and the presence of crystalline rocks and laterite deposits. In contrast, the low salinity plumes and suspended sediments were markedly low in the southern region due to limited river discharge and a predominance of sedimentary rocks and coastal alluvium that supported sandy sediments. This resulted in a spatial change in benthic sediment texture as well, with the central and northern regions more silty or clayey, while the south was sandy. Interestingly, the sandy south section had a noticeably higher faunal abundance than the rest of the region with an increased abundance of sensitive fauna of molluscs and echinoderms. This is a clear case of how spatially varying river discharge and sediment flux impact the nearshore environment and fauna.

4.
Mar Pollut Bull ; 208: 116997, 2024 Sep 20.
Artigo em Inglês | MEDLINE | ID: mdl-39305844

RESUMO

We investigated trophic structures in rocky subtidal ecosystems transitioning from canopy-forming to barren states across coastlines with varying oceanographic conditions. We examined stable isotopes and functional traits of common invertebrate and fish taxa to understand the food-web consequences. We hypothesized that resource exploitation patterns of functional guilds would result in distinct isotopic niches, defining trophic diversity and niche. δ13C and δ15N ranges of invertebrate functional groups differentiated pelagic from benthic trophic pathways, reflecting flexible dietary use in the absence of macroalgae. Fish production relied on prey using pelagic and benthic basal resources. Trophic redundancy among consumers within functional guilds contributed to intrinsic trophic structure in barren ecosystems. The resulting community-wide trophic diversity has led to consistent niche widths and overlapping niche space. Overall, our findings highlight the crucial roles of consumers that persist with diverse functional guilds in conferring the adaptability of barren rocky ecosystems following habitat disturbance.

5.
PeerJ ; 12: e17581, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39221281

RESUMO

Background: Ariidae species play a significant role as fishing resources in the Amazon region. However, the family's systematic classification is notably challenging, particularly regarding species delimitation within certain genera. This difficulty arises from pronounced morphological similarities among species, posing obstacles to accurate species recognition. Methods: Following morphological identification, mitochondrial markers (COI and Cytb) were employed to assess the diversity of Ariidae species in the Amazon. Results: Our sampling efforts yielded 12 species, representing 92% of the coastal Amazon region's diversity. Morphological identification findings were largely corroborated by molecular data, particularly for species within the Sciades and Bagre genera. Nonetheless, despite morphological support, Cathorops agassizii and Cathorops spixii displayed minimal genetic divergence (0.010). Similarly, Notarius quadriscutis and Notarius phrygiatus formed a single clade with no genetic divergence, indicating mitochondrial introgression. For the majority of taxa examined, both COI and Cytb demonstrated efficacy as DNA barcodes, with Cytb exhibiting greater polymorphism and resolution. Consequently, the molecular tools utilized proved highly effective for species discrimination and identification.


Assuntos
Peixes-Gato , Código de Barras de DNA Taxonômico , DNA Mitocondrial , Animais , Peixes-Gato/genética , Peixes-Gato/classificação , DNA Mitocondrial/genética , Filogenia , Variação Genética/genética , Brasil , Complexo IV da Cadeia de Transporte de Elétrons/genética
6.
Front Vet Sci ; 11: 1400467, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39290507

RESUMO

Introduction: Explanatory models of disease focus on individuals' and groups' understandings of diseases, revealing a disconnect between livestock keepers and animal health providers. Animal health providers rely on models grounded in their veterinary training and experience. At the same time, livestock keepers may construct models based on traditional knowledge and their lived experience with East Coast fever in their cattle herds. To better understand East Coast fever and develop more efficient management strategies, this ethnographic study used the explanatory models' framework to provide a structured way for comprehending and contrasting different beliefs and understandings of East Coast fever as perceived by the livestock keepers across the different livestock production systems. Method: Multiple data collection methods were employed, including unstructured observations, 30 in-depth interviews (IDIs), 18 focus group discussions (FGDs), and 25 key informant interviews (KIIs). Results: Adult cattle, calves and sheep were perceived as susceptible to East Coast fever. However, there were varying perceptions of livestock susceptible to East Coast fever in the different livestock production systems. East Coast fever was attributed to multiple factors, including ticks, tsetse flies, mosquitos, birds, stagnant, dirty, or contaminated water, and livestock-wildlife interactions. However, some aspects were specific to the production system. Livestock keepers classified diseases based on observable signs, grouping diseases with similar signs under the same classification. Moreover, livestock keepers described different forms of East Coast fever ranging from treatable to fatal, which could be distinguished by the signs they presented. Self-treatment with drugs from the local agro-vet shops was the initial course of action during suspected cases of East Coast fever. Animal health practitioners were the last resort if self-treatment did not produce the desired outcome. Livestock keepers perceived avoidance of stagnant or contaminated water, tick control, and fencing as effective control measures for East Coast fever in their livestock herd. Very few livestock keepers were aware of an East Coast fever vaccine. Discussion: Mechanistic explanations hold little significance in controlling East Coast fever. Instead, understanding and addressing livestock keepers' beliefs regarding ECF is crucial for promoting behaviors that support interventions across different livestock production systems.

7.
Ecol Evol ; 14(9): e70293, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39290667

RESUMO

The impacts of large-scale disturbance events on the species diversity of rocky intertidal sessile assemblages across multiple spatial scales are not well understood. To evaluate the influence of the 2011 Tohoku Earthquake on alpha and beta diversities of rocky intertidal sessile assemblages, we surveyed sessile assemblages in the mid-shore zone from 2011 to 2019 and compared the data with those collected from 2003 to 2010 before the earthquake at the same region. The census was conducted across 22 study plots on five rocky shores along 30 km of the Sanriku Coast of Japan, which is located 150-160 km north-northwest of the earthquake epicenter. Alpha diversity was measured with three Hill numbers (H 0, H 1, and H 2), which represent the number of equally common species that would exist in a community with the same diversity as the sampled community, with higher values of the subscript indicating more weight placed on abundant species. Beta diversity was measured with two metrics (BD total at two spatial scales). Values were compared between the post-earthquake period (2011-2019) and the pre-earthquake period (2003-2010). The results show that the Tohoku Earthquake significantly altered the species diversity of intertidal sessile assemblages across multiple spatial scales. All diversity metrics obtained at multiple spatial scales (i.e., alpha diversities: H 0, H 1, and H 2; beta diversities: BD total at the shore and regional scales) decreased immediately after the earthquake and then increased in subsequent years. At 2 years after the earthquake, H 0 recovered to within the range of pre-earthquake values and H 1 and H 2 became significantly higher than pre-earthquake values. Most metrics of alpha and beta diversities recovered to pre-earthquake levels after several years, but regional BD total remained low for a longer period.

8.
Zool Stud ; 63: e1, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39246702

RESUMO

Rhizocephala is a group of endoparasitic barnacles, the morphological characteristics of which are degenerated, and which has recently undergone active molecular identification. Despite several recent studies of Korean rhizocephalans, a comprehensive analysis of rhizocephalan fauna has not yet been conducted. In this study, we analyzed morphological and molecular characteristics of 64 rhizocephalan samples from 15 decapod hosts sampled across the Korean coast. We found 16 Rhizocephala species of six genera from four Rhizocephala families, i.e., Peltogasterellidae, Peltogastridae, Polyascidae, and Sacculinidae. Combining morphological examination and molecular analysis of mitochondrial cytochrome c oxidase I revealed three new species candidates, i.e., Peltogasterella sp., Peltogaster sp., and Parasacculina sp. 1, and three rhizocephalans that have expanded their distribution range to the Korean coast, i.e., Parasacculina oblonga, Sacculina angulata, and Sacculina gracilis, whose expanded their distribution range to Korean coast. A synthetic update of Korean Rhizocephala fauna including a species checklist and remarks regarding distribution and taxonomy is also presented.

9.
Ann Med ; 56(1): 2398199, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39233624

RESUMO

The diagnosis of amyotrophic lateral sclerosis (ALS) is based on evidence of upper and lower motor neuron degeneration in the bulbar, cervical, thoracic, and lumbar regions in a patient with progressive motor weakness, in the absence of differential diagnosis. Despite these well-defined criteria, ALS can be difficult to diagnose, given the wide variety of clinical phenotypes. Indeed, the central or peripheral location of the disease varies with a spectrum ranging from predominantly central to exclusively peripheral, symptoms can be extensive or limited to the limbs, bulbar area or respiratory muscles, and the duration of the disease may range from a few months to several decades. In the absence of a specific test, the diagnostic strategy relies on clinical, electrophysiological, biological and radiological investigations to confirm the disease and exclude ALS mimics. The main challenge is to establish a diagnosis based on robust clinical and paraclinical evidence without delaying treatment initiation by increasing the number of additional tests. This approach requires a thorough knowledge of the phenotypes of ALS and its main differential diagnoses.


The diagnosis of amyotrophic lateral sclerosis (ALS) is based on progressive degeneration of upper and lower motor neurons.ALS can be difficult to diagnose due to the wide range of clinical phenotypes (central/peripheral location, symptom distribution, disease duration).A thorough diagnostic strategy including clinical, electrophysiological, biological and radiological investigations is essential to confirm ALS and exclude differential diagnoses.


Assuntos
Esclerose Lateral Amiotrófica , Esclerose Lateral Amiotrófica/diagnóstico , Esclerose Lateral Amiotrófica/fisiopatologia , Humanos , Diagnóstico Diferencial , Eletromiografia/métodos
10.
Sci Total Environ ; 951: 175884, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39216760

RESUMO

Although seagrass meadows are intense carbon sinks, information on the regional variability in seagrass blue carbon stocks and carbon sequestration remains limited. We estimated the organic carbon (Corg) stocks and carbon accumulation rates (CAR) of seven seagrass meadows along the subtropical coast of China's Zhanjiang City and analyzed the driving factors of variability in sediment Corg stocks in three seagrass meadows. Results showed that most Corg (99.83 %) was stored in the sediments, and the contribution of living biomass was minor. The average Corg stocks of living biomass and sediments across all sites were 0.04 ± 0.01 and 42.03 ± 25.07 Mg C ha-1, respectively, which were significantly lower than the world average (2.52 ± 0.48 and 194.2 Mg C ha-1). The sediment Corg stocks of the upper 1 m ranged from 24.26 to 157.12 Mg C ha-1 with substantial variability among sites: Liusha Bay (64.93 ± 22.31 Mg C ha-1) > Donghai Island (33.8 ± 10.65 Mg C ha-1) > Dongshen Ferry (27.35 ± 4.15 Mg C ha-1). The average sediment CAR was 53.47 g C m-2 yr-1, and the total CAR of 864.18 ha seagrass meadows was 260.76 ± 4.86 Mg C yr-1 in these studied sites. Physicochemical factors, such as high moisture content, salinity, CaCO3 content, and low dry bulk density, jointly inhibited the mineralization rate of Corg in sediments. Our study provides data from understudied regions to a growing dataset on seagrass carbon stocks and sequestration rates and highlights the significance of local and regional differences in seagrass blue carbon storage to accurately assess the climate change mitigation potential of seagrass ecosystems.


Assuntos
Sequestro de Carbono , Monitoramento Ambiental , China , Sedimentos Geológicos/química , Carbono/análise , Biomassa , Alismatales/metabolismo
11.
Environ Pollut ; 360: 124656, 2024 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-39116927

RESUMO

The aim of this study was to investigate the presence of alien phytoplankton species transported through ballast water of ships that docked on the Amazon coast. Phytoplankton samples were collected from 25 ships between 2012 and 2014, revealing 215 identified species, mostly comprising oceanic planktonic marine species. However, several coastal and freshwater species not yet documented on the Maranhão coast were also observed. The identification of several coastal and freshwater species not yet recorded for Amazonian environments in the ballast water of the Ponta da Madeira Maritime Terminal (TMPM), as well as toxic microalgae genera such as the dinoflagellates Alexandrium and Gymnodinium and of some diatom species from the genus Pseudo-nitzchia, raises concerns regarding the possibility of introducing species. This indicates that ballast water can be responsible for the introduction of alien species in Amazonian aquatic environments, thereby highlighting the TMPM as a critical hotspot in the Amazonian region.


Assuntos
Monitoramento Ambiental , Espécies Introduzidas , Fitoplâncton , Brasil , Navios , Diatomáceas , Dinoflagellida , Água do Mar/química , Água Doce
12.
Environ Monit Assess ; 196(9): 828, 2024 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-39164565

RESUMO

Globally, there is growing concern over the environmental contamination of coastal ecosystems caused by anthropogenic activities. Here,we performed a study to evaluate the degree of heavy metal contamination in 5 different sediment samples collected from five sites along the Southeastern coast of India. Additionally, the research aims to explore the potential ecological implications of heavy metal contamination on the bacterial diversity, a crucial factor in upholding a sustainable ecosystem. A total of  seven heavy metals, i.e., chromium (Cr), copper (Cu), nickel (Ni), lead (Pb), mercury (Hg), cadmium (Cd) and arsenic (As), were assessed and quantified using inductively coupled plasma mass spectrometry. Targeted amplicon sequencing revealed that phylum Proteobacteria (36.9%) was the most dominating followed by Halobacterota (25.5%), Actinobacteriota (15%), Firmicutes (6.7%), Bacteroidota (4.0%), Thermoplasmatota (2.3%), Acidobacteriota (2.0%), Chloroflexi (1.6%), Planctomycetota (1.2%) and Crenarchaeota (1.1%). According to the alpha diversity estimate, lesser bacterial diversity was observed in areas with high pollution levels. Moreover, the physicochemical parameters of the sediments were analyzed. The contamination levels of the sediments were evaluated using the geo-accumulation index (Igeo), contamination factor (CF) and pollution loading index (PLI) to ascertain the comprehensive toxicity status of the sediments. The Igeo values revealed sediment pollution with metals such as Hg and Cd. The sediments obtained from the sampling site PU-01 showed the highest concentration of Hg pollution. Considering the ecotoxicological aspect, the estimated risk index (RI) values indicated a range from low to significant ecological risk.


Assuntos
Bactérias , Monitoramento Ambiental , Metais Pesados , Poluentes Químicos da Água , Índia , Metais Pesados/análise , Bactérias/classificação , Bactérias/genética , Bactérias/isolamento & purificação , Bactérias/efeitos dos fármacos , Poluentes Químicos da Água/análise , Sedimentos Geológicos/microbiologia , Sedimentos Geológicos/química , Biodiversidade
13.
Environ Sci Pollut Res Int ; 31(42): 54534-54545, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39207614

RESUMO

Marine plastic debris has emerged as a pressing concern along the northern coast of Jaffna, Sri Lanka, posing a significant threat to marine resources. A preliminary study was conducted to investigate the abundance and characteristics of marine plastic debris at four major fish landing sites in the northern coast of Jaffna, using the Clean Coast Index (CCI) and Plastic Abundance Index (PAI). The results revealed that the average abundance of marine debris and plastic debris were 1.71 ± 0.42 items/m2 and 1.66 ± 0.57 items/m2, respectively. The most common types of plastic debris represented plastic rope and net pieces (23.2%), followed by unidentified weathered plastic fragments (16.7%), beverage bottles (16.2%), bottle caps and lids (13%), and styrofoam (14.1%). The recognized sources of plastic debris were mainly fishing-based activities, recreation activities, transboundary sources, and unidentified sources. The fish landing sites were classified as exceptionally polluted, with a CCI exceeding 10 and a PAI value exceeding 8. Myliddy had the highest debris density, indicating substantial pollution levels, followed by Point Pedro, Mathagal, and Valveddithurai. These findings underscore the urgency of establishing a comprehensive plastic waste management framework for the northern coast of Jaffna and devising strategies to address buoyant debris within the northern Indian Ocean. Furthermore, this study carries significant implications for the local marine ecosystem, coastal communities, and Sri Lanka's broader environmental policies and practices.


Assuntos
Monitoramento Ambiental , Plásticos , Sri Lanka , Animais , Resíduos , Peixes
14.
Heliyon ; 10(14): e34745, 2024 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-39130453

RESUMO

Over recent decades, coastal and marine tourism has significantly contributed to the degradation of coastal features and ecosystems. This study employs the Integrated Valuation of Ecosystem Services (ES) and Trade-offs (InVEST) software to assess the impact of nature-based tourism activities over 13-year periods, particularly focusing on the exposed coast of Bangladesh where most touristic activities occur. The visitation rate from the InVEST model showed a gradual increase from 2005 to 2012, followed by a decline until 2017. The western coast recorded a visitation rate ranging from 1 to 72 (low to moderate), while the eastern coast ranged between 16 and 343 (moderate to high). The real-time data of visitation rate (RTD) for the Sundarbans generally aligns with the model outputs, although occasional irregularities exist in certain years, attributed to local geomorphological inaccessibility and technological limitations. Along the central coast, the visitation rate varied from 2 to 50 (low rate) Photo-User Day (PUD) index. The findings offer valuable insights for future policymaking, facilitating the effective management of tourist sites and promoting sustainable blue economic development in this diverse and vulnerable exposed coastal zone.

15.
Ann Hum Genet ; 2024 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-39092543

RESUMO

The primary etiology of congenital hearing loss is attributed to genetic factors, with GJB2 identified as a pivotal gene across diverse ethnic groups. Additionally, nonsyndromic hearing loss is predominantly inherited in an autosomal recessive manner. We used Sanger sequencing to analyze GJB2 in 17 deaf children from 13 unrelated Ivory Coast families. One family had two children born with severe congenital deafness and exhibited pathogenic compound heterozygous variants. These variants included a nonsense substitution (c.132G > A or p.Trp44Ter) and a newly discovered duplication of 7 base pairs (c.205_211dupTTCCCCA or p.Ser72ProfsTer32). Segregation testing confirmed these variants, marking the first identification of GJB2 in an Ivorian family with congenital hearing loss.

16.
Ticks Tick Borne Dis ; 15(6): 102386, 2024 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-39128161

RESUMO

Instead of using the Infection and Treatment Method (ITM)-based vaccine, is it possible to control East Coast Fever (ECF) through blocking Theileria parva transmission in ticks and cattle? This review pursues this question. It's over 100 years since Arnold Theiler (1912) first illustrated the natural ITM as a vaccination approach against ECF-cattle disease. The approach entails infecting cattle with live Theileria sporozoites and co-treatment with long-acting tetracycline. Building on the ITM principle, the "Muguga"-cocktail ECF vaccine was developed in the 1970s and it remains the only commercially available-one. Although the vaccine induces cattle-protection, the vaccination approach still raises several drawbacks. Of those, the most outstanding is the vaccine-safety. This is implied because after ITM vaccination, cattle revert to T. parva pathogen reservoirs, therefore, during blood meal-acquisition, the ticks co-ingest T. parva pathogens. Ultimately, the pathogens are further transmitted transstadial; from larvae to nymph and nymph-adults and later re-transmitted to cattle during blood-meal acquisition. Consequently, the vaccine-constituting T. parva strains are introduced and (re) spread in non-endemic/ endemic areas. Precisely, rather than eradicating the disease, the ITM vaccination-approach promotes ECF endemicity. With advent of novel vaccination approaches toward vector and vector-borne disease control, ECF-control based on ITM of vaccination is considered outdated. The review highlights the need for embracing a holistic integrative vaccination approach entailing blocking Theileria pathogen-development and transmission both in the ticks and cattle, and/or the tick-population.

17.
J Hazard Mater ; 477: 135272, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39098199

RESUMO

Microplastics (MP; 1 µm-5 mm) and microfibers (MF; thin, elongated particles with a high-length-to-width ratio) have become a major global environmental issue due to their ubiquity in the oceans and possess complex physicochemical properties that vary their mobility, bioavailability, and toxicity toward organisms and interactions with their surrounding pollutants. Nonetheless, a reliable methodology that would facilitate and automate the monitoring of MP is still lacking. Intending to select practical and standardized methods and considering the challenges in MPs detection, a new analysis protocol based on optical microscopy for the counting and morphological analysis of the particles has been developed. This method overcomes some issues related to the lack of practicality and standardization of the others currently applied, and does not involve sieving, washing, heating, or density separation and digestion processes. Our method is green and requires a minimum quantity of sediment, i.e., 1.5 g, and shortened timeframes. Future research efforts may need to develop and implement new analytical tools and combinations of technologies to complement respective detection limitations and yield reliable characterization of both MFs and MPs. We tested our protocol to study, for the first time, both marine and land sediment in the Vesuvian area of the Gulf of Naples (Italy).

18.
Environ Sci Pollut Res Int ; 31(38): 50746-50766, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39103579

RESUMO

Dakhla Bay, situated on the African Atlantic coast, has witnessed sporadic harmful algal blooms (HABs) caused by toxic dinoflagellate species over the past two decades. In this study, we investigated the distribution, abundance, and diversity of dinoflagellate cysts, with a focus on potentially toxic species that develop in this ecosystem where such data are lacking. Sediment samples were collected in April 2018 through coring at 49 stations distributed across the bay. The highest abundance of dinoflagellate cysts was recorded at 304 cysts/g dry sediment, observed at the inner part of the bay, indicating that this area is the preferential zone for cyst accumulation. Pearson's tests revealed significant positive correlations (P < 0.05) between cyst abundance and the water content, organic matter, and fine fraction (< 63 µm) of the sediment. Cyst morphotypes of potentially toxic dinoflagellate species known to produce saxitoxins, such as Alexandrium minutum, Alexandrium tamarense species complex, Gymnodinium catenatum, and yessotoxins, such as Lingulodinium polyedrum and Gonyaulax cf. spinifera, were identified in the sediment of Dakhla Bay. These findings were further supported by our long-term monitoring period (2005-2018), underscoring the presence of these HAB species in Dakhla Bay. During our survey, sporadic mollusk intoxication events were recorded at station PK25 for the grooved razor shell Solen marginatus and at station Boutelha for the oyster Crassostrea gigas. Paralytic shellfish toxin concentrations exceeded the sanitary threshold (80 µg STX di-HCl eq/100 g of shellfish meat) only twice, in December 2006 and January 2007 at station PK25. Contamination by amnesic shellfish toxins occurred sporadically but never reached the sanitary threshold of 20 µg/g of shellfish meat. Lipophilic shellfish intoxication occurred multiple times in the two investigated areas. These observations suggest that the cysts of the identified HAB species germinated and inoculated the water column, resulting in the observed intoxication events. Relatively low levels of intoxication could be attributed to the moderate abundances of cysts, which may reduce the seeding capacity. This could be explained by the significant interaction of Dakhla Bay with the Atlantic Ocean, characterized by hydrological dynamics that impede the deposition and accumulation of cysts in the bay's sediments. This study reaffirms the importance of investigating dinoflagellate cysts in assessing the diversity of HAB species and evaluating associated sanitary risks.


Assuntos
Baías , Dinoflagellida , Sedimentos Geológicos , Proliferação Nociva de Algas , Animais , Sedimentos Geológicos/química , Monitoramento Ambiental , Moluscos , Toxinas Marinhas
19.
J Anal Toxicol ; 2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-39087259

RESUMO

One of the quickest-growing subclasses of novel psychoactive substances is novel synthetic opioids (NSO), which are categorized as fentanyl analogs (fentalogs) or non-fentanyl opioids that bind to the mu-opioid receptor. Increased detections of NSO have been observed in the United States. However, limited information on their prevalence outside of the East Coast is available. This study details the prevalence of NSO, specifically fluorofentanyl, in the biological and drug paraphernalia specimens of accidental overdose deaths in San Francisco in 2022. A recently developed and validated LC-MS-MS method was utilized for the analysis of over 250 NSO. Out of the 649 accidental overdose deaths in 2022, 617 cases were available for blood analysis, with at least one NSO detected in 48 cases (7.8%). Fentalogs were detected in all 48 cases, with fluorofentanyl being detected in 40 cases. In postmortem femoral blood, estimated concentrations of fluorofentanyl ranged from 0.1 to 8.9 ng/mL, and 0.05 to 85 ng/mL in urine. Polysubstance use with NSO was seen with fentanyl (89.6%), methamphetamine (70.8%), cocaine (33.3%), and heroin (18.8%). NSO, mainly, fluorofentanyl were observed in matched drug paraphernalia. This report documents the migration of fluorofentanyl to the West Coast, specifically California.

20.
Mar Environ Res ; 201: 106712, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39213894

RESUMO

Evaluating the functional structure of benthic macrofaunal communities provides insights into how environmental drivers shape the ecosystem and establishes a baseline knowledge of the communities' dynamics and functioning. This understanding allows the prediction of responses to environmental changes and the implementation of efficient conservation and management strategies. Here we examine the structures and functions of benthic macrofaunal communities on the Northwest Iberian coast concerning environmental factors such as depth, hydrodynamic energy, and bottom type. The results suggest that the community assemblages and their function are structured by factors which influence food availability and habitat heterogeneity. The different sites exhibited different trait compositions and functional structures, indicating that distinct functions are performed according to environmental conditions. The communities found in sandy bottom areas with low hydrodynamic conditions presented frail functionality and demonstrated high vulnerability to alterations in their environment. Conversely, the communities found in rocky bottoms with high hydrodynamic conditions exhibited a fulfilled functional niche space, rendering them more resilient to such changes and less prone to loss of function. Although the analyses did not reveal significant differences in the factor depth, its influence on several factors seems relevant in shaping the functional structure of the communities. These findings highlight the importance of understanding the impact of local environmental conditions on ecosystem functioning, to effectively implement monitoring, management, and conservation strategies.


Assuntos
Ecossistema , Monitoramento Ambiental , Animais , Espanha , Biodiversidade , Organismos Aquáticos/fisiologia , Invertebrados/fisiologia , Sedimentos Geológicos/química
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