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1.
Food Chem ; 366: 130532, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34274702

RESUMO

One major pepsinogen, PG-I, and two minor pepsinogens, PG-II and PG-III were purified from lizardfish stomach by ammonium sulfate precipitation and two chromatographic columns. The three purified PGs migrated as single bands in native-PAGE gels with molecular weights (MW) ranging from 36 to 38 kDa. Each PG was converted to pepsin (P) at pH 2.0, and the MW were determined as 32 kDa (for P-I), 31 kDa (for P-II) and 30 kDa (for P-III). The optimum pH and temperature of pepsins were 2.0-3.5, and 40-50 °C. All 3 pepsins were strongly inhibited by pepstatin A. Divalent cations slightly stimulated the pepsin activities, but ATP had no effect on the pepsins. Purified pepsins were effective in the hydrolysis of various proteins. Km and kcat of the three pepsins for hemoglobin hydrolysis were 107.64-276.61 µM and 18.30-32.68 s-1, respectively. The new pepsins have potential for use in protein food procession and modification.


Assuntos
Pepsina A , Pepsinogênios , Sequência de Aminoácidos , Animais , Peixes/metabolismo , Pepsina A/metabolismo , Pepsinogênios/metabolismo , Estômago
2.
Food Chem ; 366: 130600, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34311237

RESUMO

The effect of dual-frequency sequential ultrasonic thawing (DUT) on the quality of quick-frozen small yellow croaker was studied by TMT-labeled quantitative proteomic method. A total number of 75 proteins were identified as differentially abundant proteins (DAPs) in fish meat treated by DUT, while 72 DAPs were in flow water thawing (FWT). The Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis indicated that the DAPs in the significant enrichment pathway of DUT group were enzymes. Compared with FWT, DUT had a significant effect on the enzyme content. The correlation analyses indicated that 40 DAPs were related with the quality traits. The 11 highly correlated DAPs are expected to be used as potential protein markers for texture profile analyses, color, thawing loss, water-holding capacity, and pH of thawed small yellow croaker quality. These results provide a further understanding of the quality stability of quick-frozen small yellow croaker treated by the DUT.


Assuntos
Perciformes , Proteômica , Animais , Peixes , Genoma , Carne , Perciformes/genética
3.
Food Chem ; 367: 130728, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34380107

RESUMO

Fish protein hydrolysates (FPH) obtained from industrial processing residues are sources of bioactive peptides. The enzymatic hydrolysis process is essential in obtaining specific bioactivities such as inhibition of the enzyme acetylcholinesterase (AChE). In this study the effect of different hydrolysis conditions on the properties of FPH to inhibit the enzyme acetylcholinesterase. A chemometric evaluation, based on a central composite rotatable design and principal component analysis, was applied to select hydrolysis conditions with best yield, degree of hydrolysis and acetylcholinesterase inhibition. Experimental design results for AChE inhibition were between 10.51 and 40.45% (20, 30 and 50 mg.mL-1 of FPH), and three hydrolysis conditions were selected based on PCA evaluation. The amino acids profile, FTIR and AChE inhibition kinetics were evaluated. Results showed a mixed type of inhibition behavior and, the docking molecular analyzes suggest that the inhibition AChE occurred due to the basic amino acids, mainly by arginine.


Assuntos
Acetilcolinesterase , Hidrolisados de Proteína , Animais , Peixes , Hidrólise , Peptídeos
4.
Sci Total Environ ; 802: 149620, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34461474

RESUMO

Triggered by the adoption of the Water Framework Directive, a variety of fish-based systems were developed throughout Europe to assess the ecological status of lakes. This paper provides a comprehensive overview of all existing systems and summarizes sampling methods, fish community traits (metrics) and the relevant anthropogenic pressures assessed by them. Twenty-one European countries developed fish-based assessment systems. Three countries each developed two distinct systems to approach different ecoregions, either to use different data, or to assess different lake types leading to a total number of 24 systems. The most common approach for the setting of reference conditions, used in seventeen systems, was the utilisation of fish communities in comparably undisturbed natural lakes as reference. Eleven used expert judgment, nine historical data and eight modelled relationships. Fourteen systems combined at least two approaches. The most common fish sampling method was a standardized fishing procedure with multimesh-gillnets. Many countries applied combinations of fishing methods, e.g. non-standard gillnets, fyke nets and electrofishing. Altogether 177 metrics were used for index development and each system combined 2-13 metrics. The most common ones were total standardized catches of number and biomass, relative abundance of Perca fluviatilis, Rutilus rutilus, and Abramis brama, feeding preferences, sensitive species, and non-natives. The pressure-response-relationships for these metrics were supported with both correlations established during system development and scientific publications. However, the metrics and their combinations were highly diverse and no metric was applied universally. Our analysis reveals that most fish-based assessment systems address multiple pressures (eutrophication, hydromorphological alterations, fishery pressure and occurrence of non-natives), whilst few are pressure-specific, tackling only eutrophication or acidification. We argue that the value of fish-based systems for lakes lies in their capacity to capture the effect of many different pressures and their interactions which is lacking for most assessment systems based on other biota.


Assuntos
Lagos , Percas , Animais , Ecossistema , Monitoramento Ambiental , Eutrofização , Pesqueiros , Peixes
5.
Sci Total Environ ; 802: 149720, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34464804

RESUMO

Barrier removal and fish pass construction are increasingly used as tools to restore river connectivity and improve habitat quality, but the effectiveness of subcatchment-scale connectivity restoration on recovery of fish communities is poorly understood. We used a before-after-downstream-upstream methodology to determine the effects of subcatchment-scale connectivity restoration on fishes in a fragmented tributary of the River Wear, Northeast England, between 2013 and 2019. Following restoration (three barriers removed, five barriers fitted with fish passes, two barriers unaltered), riffle habitat increased, fine sediment decreased, and most fish species benefitted. Total fish abundance, comprising seven native species, increased 3 years after the restoration and remained elevated to the end of the study. Mean brown trout (Salmo trutta) density increased from 20.9 ±â€¯6.3 to 33.8 ±â€¯16.8 per 100m2 from 2013 to 2019, with Young-of-Year trout increasing from 10.6 ±â€¯4.6 to 19.8 ±â€¯11.8 per 100m2. Connectivity restoration reduced the mean age of trout, suggesting a change to an increased migratory component of the population. Density of bullhead (Cottus perifretum), a species with poor dispersal ability, increased from 4.6 ±â€¯2.7 to 32.6 ±â€¯17.9 per 100m2 over 2013 to 2019. Stone loach (Barbatula barbatula), also a less mobile species but tolerant to fine sediment, decreased in abundance where barriers were removed. Atlantic salmon (Salmo salar) were absent over the study timescale, despite being common in the Wear, and despite suitable habitat and water quality in the restored subcatchment, suggesting a hysteresis effect. Our findings indicate that, where good water quality exists, restoring river connectivity and hydromorphology at a subcatchment scale is beneficial for most native resident and migratory fishes. However, the ecological benefits of connectivity restoration, especially in rivers with many barriers, may take several years to develop. We encourage well-controlled long-term studies reporting the outcomes of large-scale connectivity restoration.


Assuntos
Cipriniformes , Perciformes , Animais , Ecossistema , Peixes , Rios , Truta
6.
Sci Total Environ ; 802: 149891, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34474296

RESUMO

Animals exposure to polychlorinated biphenyls (PCBs) may result in retention of hydroxylated PCBs (OH-PCBs). OH-PCBs can be accumulated in animals, including humans, through the transmission of food chain. However, there are few studies on the accumulation and metabolism of OH-PCBs exposed to the body through daily diet. Therefore, this study was conducted to investigate the fate of OH-PCBs after being ingested through dietary intake. By adding 3-OH-PCB101 and 4-OH-PCB101 to the edible tissue of crucian carp, which were used as raw materials to prepare mouse feed, with an exposure concentration of 2.5 µg/kg ww. The exposure experiment lasted for a total of 80 days. The blood, feces and 11 tissues of mice at different times were analyzed qualitatively and quantitatively. It was found that major OH-PCB101 were accumulated in intestine or excreted with feces. A small part was accumulated in heart, lung and spleen. For the first time that the conversion from OH-PCB101 to PCB101 in mice was discovered, which shows from another perspective that persistent organic pollutants are difficult to be completely degraded in the environment. 4-MeO-PCB101, 3-MeSO2-PCB101, and 4-MeSO2-PCB101 were also found in various tissues. The results of this study show that after OH-PCBs accumulated in animals re-enter the organism through the food chain, they can be metabolized again and may be reversely transformed into the parent compounds. The present research shed new light on simulating the metabolic transformation process of OH-PCBs exposed to mammals through ingestion of fish. Available data show that second-generation persistent organic pollutants in the environment still need to be continuously concerned.


Assuntos
Poluentes Ambientais , Bifenilos Policlorados , Animais , Dieta , Peixes , Hidroxilação , Camundongos , Bifenilos Policlorados/análise
7.
J Environ Manage ; 301: 113805, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34731957

RESUMO

The consequences of protected areas for proximal human communities are diverse. Protected areas can alleviate poverty by providing a range of economic opportunities for people that live and work within them. Equally, however, they may also disempower and disposes local communities. For communities adapting to systemic environmental change, proximity to protected areas can act to limit potential adaptive pathways. Here, we employ social science methods to explore the impact of an internationally significant protected area on adjacent communities in the Tonle Sap Lake basin, Cambodia. Semi-structured interviews, informed by a scenario framework, reveal an awareness of declining fish yields and a perceived lack of economic alternatives. Vulnerability to hydroclimatic extremes, particularly storms, flood, drought and - increasingly - fire, are exacerbated as a result of proximity to the protected area. We conclude that the impact of protected areas on local communities is heterogenous, and that the development of adaptive and effective management policies requires sensitivity to local conditions and impacts.


Assuntos
Inundações , Lagos , Aclimatação , Animais , Camboja , Peixes
8.
Talanta ; 237: 122922, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34736659

RESUMO

Distribution of Se and Hg in sarcoplasmic, myofibrillar and alkali-soluble protein fractions extracted from muscle tissue of tuna, swordfish and salmon (wild vs. farmed) is investigated for the first time. SEC-UV-ICP-MS analyses revealed that Se and Hg are mostly bound to proteins of 2-12 kDa and up to 574 kDa, respectively. Moreover, Se and Hg appeared associated to proteins of same molecular weight, evidencing that Se-Hg interaction may occur at the level of the fish tissue evaluated. Important differences were found between farmed and wild salmon, suggesting the effect of the type of feed and growing conditions on Se and Hg content and their distribution through protein fractions. Finally, Se speciation studies performed by HPLC-ICP-MS and confirmed by HPLC-ESI-MS/MS showed SeMeSeCys as the only Se specie found in soluble, sarcoplasmic, myofibrillar and alkali-soluble proteins of all fishes analysed, except in soluble proteins extracted from tuna, where SeMet was also identified.


Assuntos
Mercúrio , Selênio , Animais , Cromatografia Líquida de Alta Pressão , Peixes , Músculos , Espectrometria de Massas em Tandem , Atum
9.
Environ Pollut ; 292(Pt A): 118360, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34653584

RESUMO

Muscle melanisation in sand flathead is visible as black spots in the normally white flesh of fish. It is widespread in Tasmania, including at the Tamar Estuary, with increasing frequency of reporting by recreational fishers. The phenomenon is more prevalent in areas impacted by heavy metal pollution and has been linked to heavy metal accumulation. In this study, image processing software ImageJ was employed to study the phenomenon and to establish an objective rating system. A longitudinal profile plot was used to study the greying of the fillet. The degree of melanisation was rated based on the percentage surface area melanised on the surface and in transverse sections of fillets. A muscle melanisation scoring system for sand flathead was established based on visual interpretation using the macroscopic melanisation scoring criteria: melanisation scores 0 = <0.5%, 1 = 0.5-5%, 2 = 5-20%, and 3 = >20% (% = melanised surface area in proportion to the whole fillet). A refined image analysis technique was developed to quantify the percentage of melanised muscle surface area and the muscle melanisation scoring system was statistically validated. Sand flathead fillet with higher melanisation score was shown to be linked to increased intensity of greyness and greater numbers and size of black spots on the surface of fillets and within the flesh. The greying and black spots were primarily concentrated at the anterior region of fillet and around the dorsal vertebrae zone on transverse section of fillets. Overall, findings from this study established the use of image analysis techniques to validate visual inspection and to give a standardised and objective method to determine the degree of melanisation in sand flathead. As muscle melanisation appears to be linked to heavy metal pollution, the standardised scoring system would facilitate future research for environmental pollution and monitoring purposes.


Assuntos
Perciformes , Poluentes Químicos da Água , Animais , Estuários , Peixes , Músculos/química , Poluentes Químicos da Água/análise
10.
Environ Pollut ; 292(Pt B): 118459, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740732

RESUMO

Fish community manipulation and regulation has been largely overlooked as a mitigation strategy for restoring submerged aquatic vegetation (SAV) in shallow lakes of the middle and lower Yangtze River Basin (MLYRB). An in-situ fish exclusion experiment and a large-scale lake manipulation were conducted to test the hypothesis that the reasonable removal of benthivorous and herbivorous fish would facilitate the restoration and reconstruction of SAV in shallow lakes within the MLYRB. The in-situ exclusion experiment was conducted from April to October in 2017. Electrofishing was used to remove benthivorous and herbivorous fish from the exclosures. SAV were then artificially planted in the same pattern and density in both exclosures and adjacent open sites, and responses were measured for seven consecutive months. The mean percent coverage and biomass of SAV in the exclosures increased quickly and remained significantly higher than those in open sites over the duration of the experiment. Water quality also improved as turbidity, chlorophyll-a, total phosphorus and total nitrogen in the exclosures remained significantly lower than those in the open sites. After the in-situ experiment, a larger scale manipulation of fish in the entire submerged macrophyte zone (SMZ) was implemented from 2017 to 2020. After removing more than 2/3 of the benthivorous and herbivorous fish biomass by October 2020 in the SMZ, both the species richness and spatial coverage of SAV increased from 2 to 9 and from 1.7% to 32.2%, respectively. Our results provided clear evidence that fish are strong regulators of SAV productivity and that their reasonable removal facilitates ecological recovery. Therefore, we propose that fish community manipulation as implemented in this study be given more attention in addition to the reduction of external nutrient loading when designing projects to restore SAV in shallow lakes of the MLYRB.


Assuntos
Ecossistema , Lagos , Animais , Clorofila A , Peixes , Fósforo
11.
Environ Pollut ; 292(Pt B): 118451, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34740735

RESUMO

The assessment of contaminant exposure in marine organisms often focuses on the most toxic chemical elements from upper trophic level species. Information on mid-trophic level species and particularly on potentially less harmful elements is lacking. Additionally, microplastics have been considered emergent contaminants in aquatic environments which have not been extensively studied in species from mid-trophic levels in food chains. This study aims to contribute to an overall assessment of environmental impacts of such chemicals in a community of small pelagic fish in the North Atlantic. The concentrations of 16 chemical elements, rarely simultaneously quantified (including minerals, trace elements and heavy metals), and the presence of microplastics were analysed in sardines (Sardina pilchardus) and mackerels (Scomber spp. and Trachurus trachurus) sampled along the Portuguese coast. Biochemical stress assessments and stable isotope analyses were also performed. The chemical element concentrations in S. pilchardus, T. trachurus, and Scomber spp. were relatively low and lower than the levels reported for the same species in the North Atlantic and adjacent areas. No clear relationships were found between chemical elements and oxidative damage in fish. However, the concentration of several chemical elements showed differences among species, being related with the species' habitat use, trophic niches, and specific feeding strategies. The presence of plastic pieces in the stomachs of 29% of the sampled fishes is particularly concerning, as these small pelagic fish from mid-trophic levels compose a significant part of the diet of humans and other top predators. This study highlights the importance of multidisciplinary approaches focusing on the individual, including position data, stable isotopes, and oxidative stress biomarkers as complementary tools in contamination assessment of the marine mid-trophic levels in food chains.


Assuntos
Microplásticos , Poluentes Químicos da Água , Animais , Monitoramento Ambiental , Peixes , Humanos , Plásticos , Poluentes Químicos da Água/análise
12.
Chemosphere ; 287(Pt 3): 132263, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34826937

RESUMO

Tapajós Region, is an area with intense historical artisanal and small-scale gold mining. Therefore, the core objective of this study was to evaluate the environmental status of different rivers located in this region, using biomarker endpoints in Serrasalmus rhombeus as a tool. Fish and sediment were collected from two rivers, Tropas and Crepori, affluent of Tapajós River, located inside a Federal Protection Area and in a Reference site. Mercury concentration in sediment and fish were traced, and biomarkers in gills and liver were analyzed. Results showed a clear difference between these two rivers compared to the Reference site. Fish tissues presented biomarker responses according to the site of collection. Catalase (CAT) activity was statistically higher in fish gills from Crepori, confirming the capacity of mercury interference with redox equilibrium. High levels of lipid peroxidation were also noted to contribute greatly in incidence of morphological changes in the liver and gills, suggesting that mercury bioaccumulation during continuous exposure promote biological responses in a cumulative manner, from molecules to tissues. This study also indicates adaptation in fish defense mechanisms given the conditions in the Tropas River, as well as a variation in biomarker responses to that of the Crepori river. In summary, Tapajós affluents presented high mercury levels in fish tissues leading to biomarker responses, demonstrating a hazardous signal of a long history of mercury pollution.


Assuntos
Mercúrio , Poluentes Químicos da Água , Animais , Biomarcadores , Monitoramento Ambiental , Peixes , Ouro , Mercúrio/análise , Mercúrio/toxicidade , Mineração , Rios , Poluentes Químicos da Água/análise , Poluentes Químicos da Água/toxicidade
13.
Sci Total Environ ; 806(Pt 1): 150419, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34560450

RESUMO

Scavengers provide significant nature's contributions to people (NCP), including disease control through carcass removal, but their non-material NCP are rarely considered. For the first time, we assess the extent and value of the NCP provided by European avian scavengers through a scavenger-based tourism at Pyrenean supplementary feeding sites (SFS). Using a two-step cluster analysis, two different types of visitor were identified (specialist avian scavenger-watchers and generalist nature-lovers) at those SFS offering recreational experiences (n = 20, i.e. birdwatching, educational, or photographic activities). Most visitors (85%) perceived avian scavengers as beneficial NCP providers, associating this guild with non-material NCP (mostly supporting identities), followed by regulating and maintenance of options NCP (<1%). Our findings help to characterize the type of people who participate in scavenger related recreation and to identify and value their perceptions of avian scavengers. There has not been much previous research on positive human-wildlife interactions, even though ignoring people emotional bonds with nature can be perilous for biodiversity conservation.


Assuntos
Animais Selvagens , Turismo , Animais , Biodiversidade , Aves , Conservação dos Recursos Naturais , Ecossistema , Peixes , Humanos
14.
Vet Clin North Am Exot Anim Pract ; 25(1): 13-29, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34823688

RESUMO

Veterinarians often need to sedate or anesthetize fish to perform physical examinations or other diagnostic procedures. Sedation may also be required to transport fish. Painful procedures require complete anesthesia with appropriate antinociceptive agents. Regulations and withdrawal times apply to food animal species in many countries. Specific protocols are therefore warranted in commercial fish versus ornamentals. Tonic immobility of elasmobranchs and electric anesthesia should never be used to perform painful procedures. Anesthetic monitoring in fish remains challenging. This review summarizes ornamental fish anesthesia and discusses techniques used in the commercial fish industry and in field conditions.


Assuntos
Anestesia , Médicos Veterinários , Analgésicos/uso terapêutico , Anestesia/veterinária , Animais , Peixes , Humanos , Dor/tratamento farmacológico , Dor/veterinária
15.
Acta Trop ; 225: 106211, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34687648

RESUMO

The parasitic copepod genus Parabrachiella is composed of 70 species, 14 of which are found in South America. The finding of new specimens of Parabrachiella mugilis from Turkey allowed us to compare the nucleotide sequences of the mitochondrial cytochrome c oxidase subunit I (COI) gene of this species with those of the South American Parabrachiella exilis and Parabrachiella platensis; all these species are parasites of mugilids. In addition, specimens of Parabrachiella fasciata, Parabrachiella oralis and Parabrachiella dispar from Chile, and Parabrachiella chevreuxi from Argentina were included in the comparison. Our results confirmed that the three Parabrachiella species parasitizing mugilids, which had been identified by morphology, are valid entities. However, P. exilis was recently synonymized with P. mugilis. The latter species showed a great genetic distance from P. exilis (16%) and was closer to Parabrachiella fasciata (13%) and to species with long posterior processes. Parabrachiella exilis and P. platensis (parasite on Mugil cephalus and Mugil liza, respectively) had a low genetic distance (9%) and Parabrachiella kabatai (parasite of Isacia conceptionis) had a low genetic distance (12-13%) from P. fasciata, P. platensis and P. exilis. In addition, the three parasitic copepods from South America have short and round posterior processes compared to other species, which have long posterior processes. Most species with long posterior processes are clustered together in a Pacific Ocean clade (P. hugu from the North Pacific Ocean), with the exception of P. chevreuxi, which has been found in the South Atlantic Ocean. This study adds seven new sequences, making a total of nine sequenced South American species of Parabrachiella.


Assuntos
Copépodes , Smegmamorpha , Animais , Oceano Atlântico , Chile , Copépodes/genética , Peixes
16.
Sci Total Environ ; 804: 150167, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34798731

RESUMO

Climate change often leads to shifts in the distribution of small pelagic fish, likely by changing the match-mismatch dynamics between these sensitive species within their environmental optima. Using present-day habitat suitability, we projected how different scenarios of climate change (IPCC Representative Concentration Pathways 2.6, 4.5 and 8.5) may alter the large scale distribution of European sardine Sardina pilchardus (a model species) by 2050 and 2100. We evaluated the variability of species-specific environmental optima allowing a comparison between present-day and future scenarios. Regardless of the scenario, sea surface temperature and salinity and the interaction between current velocity and distance to the nearest coast were the main descriptors responsible for the main effects on sardine's distribution. Present-day and future potential "hotspots" for sardine were neritic zones (<250 km) with water currents <0.4 m s-1, where SST was between 10 and 22 °C and SSS > 20 (PSU), on average. Most variability in projected shifts among climatic scenarios was in habitats with moderate to low suitability. By the end of this century, habitat suitability was projected to increase in the Canary Islands, Iberian Peninsula, central North Sea, northern Mediterranean, and eastern Black Sea and to decrease in the Atlantic African coast, southwest Mediterranean, English Channel, northern North Sea and Western U.K. A gradual poleward-eastward shift in sardine distribution was also projected among scenarios. This shift was most pronounced in 2100 under RCP 8.5. In that scenario, sardines had a 9.6% range expansion which included waters along the entire coast of Norway up and into the White Sea. As habitat suitability is mediated by the synergic effects of climate variability and change on species fitness, it is critical to apply models with robust underlying species-habitat data that integrate knowledge on the full range of processes shaping species productivity and distribution.


Assuntos
Mudança Climática , Ecossistema , Animais , Peixes , Previsões , Temperatura
17.
J Environ Manage ; 301: 113898, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34626943

RESUMO

In shallow eutrophic lakes, submersed macrophytes are essential for maintaining a clear water state, and they are affected markedly by fishes directly through herbivory and indirectly by fish-invertebrate-periphyton complexity, a pathway that presently is not well understood in subtropical lakes but probably vital to lake managements. We conducted a mesocosm study involving benthic fish (Misgurnus anguillicaudatus), snails (Radix swinhoei) and submersed macrophyte (Vallisneria natans), aiming to examine whether benthic fish is detrimental to reestablishment of clear-water macrophyte-dominated state in eutrophic degraded lakes. In addition, we aimed to investigate the cascading effect that benthic fish might have on periphyton and phytoplankton and to what extent snails can alleviate this effect. Our results showed that benthic fish promoted nutrient release from the sediment and thereby facilitated the growth of phytoplankton and periphyton, leading to reduced growth of submerged macrophytes due to shading. Snails consumed the periphyton attached on the leaves of macrophytes, thereby being beneficial to the plant growth, albeit it could not fully counteract the adverse effects from benthic fish. The water quality indicators in terms of nutrients concentrations, phytoplankton biomass and light extinction coefficient along the water column was affected primarily by benthic fish, followed by macrophytes and snails. To target a clear-water condition, the water quality was best at the presence of macrophytes alone or in combination with snails, and worst at the presence of benthic fish. Our results implied that the removal of benthic fish should be a useful ecological restoration method for rehabilitation of submersed macrophytes and water quality improvement in subtropic, eutrophic, shallow lakes following external nutrient loading reduction.


Assuntos
Hydrocharitaceae , Lagos , Animais , Biomassa , Peixes , Fósforo , Fitoplâncton
18.
Sci Total Environ ; 803: 149875, 2022 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-34478901

RESUMO

Invasive alien fishes have had pernicious ecological and economic impacts on both aquatic ecosystems and human societies. However, a comprehensive and collective assessment of their monetary costs is still lacking. In this study, we collected and reviewed reported data on the economic impacts of invasive alien fishes using InvaCost, the most comprehensive global database of invasion costs. We analysed how total (i.e. both observed and potential/predicted) and observed (i.e. empirically incurred only) costs of fish invasions are distributed geographically and temporally and assessed which socioeconomic sectors are most affected. Fish invasions have potentially caused the economic loss of at least US$37.08 billion (US2017 value) globally, from just 27 reported species. North America reported the highest costs (>85% of the total economic loss), followed by Europe, Oceania and Asia, with no costs yet reported from Africa or South America. Only 6.6% of the total reported costs were from invasive alien marine fish. The costs that were observed amounted to US$2.28 billion (6.1% of total costs), indicating that the costs of damage caused by invasive alien fishes are often extrapolated and/or difficult to quantify. Most of the observed costs were related to damage and resource losses (89%). Observed costs mainly affected public and social welfare (63%), with the remainder borne by fisheries, authorities and stakeholders through management actions, environmental, and mixed sectors. Total costs related to fish invasions have increased significantly over time, from

Assuntos
Ecossistema , Espécies Introduzidas , Animais , Europa (Continente) , Pesqueiros , Peixes , Humanos
19.
Sci Total Environ ; 804: 150098, 2022 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-34508930

RESUMO

Contrary to epipelagic waters, where biogeochemical processes closely follow the light and dark periods, little is known about diel cycles in the ocean's mesopelagic realm. Here, we monitored the dynamics of dissolved organic matter (DOM) and planktonic heterotrophic prokaryotes every 2 h for one day at 0 and 550 m (a depth occupied by vertically migrating fishes during light hours) in oligotrophic waters of the central Red Sea. We additionally performed predator-free seawater incubations of samples collected from the same site both at midnight and at noon. Comparable in situ variability in microbial biomass and dissolved organic carbon concentration suggests a diel supply of fresh DOM in both layers. The presence of fishes in the mesopelagic zone during daytime likely promoted a sustained, longer growth of larger prokaryotic cells. The specific growth rates were consistently higher in the noon experiments from both depths (surface: 0.34 vs. 0.18 d-1, mesopelagic: 0.16 vs. 0.09 d-1). Heterotrophic prokaryotes in the mesopelagic layer were also more efficient at converting extant DOM into new biomass. These results suggest that the ocean's twilight zone receives a consistent diurnal supply of labile DOM from the diel vertical migration of fishes, enabling an unexpectedly active community of heterotrophic prokaryotes.


Assuntos
Células Procarióticas , Água do Mar , Animais , Peixes , Processos Heterotróficos , Oceano Índico
20.
Food Chem ; 369: 130874, 2022 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-34455321

RESUMO

As one of food sources, fish provides sufficient nutrition to human. Diverse nutrients in fish make fish an important nutrient source available easily across the globe. Fish is proven to possess several health benefits, such as anti-oxidation, anti-inflammation, wound healing, neuroprotection, cardioprotection, and hepatoprotection properties. Fish proteins, such as immunoglobins, act as defense agents against viral and bacterial infections and prevent protein-calorie malnutrition. Besides, fish oil constituents, such as polyunsaturated fatty acids (PUFAs), regulate various signaling pathways, such as nuclear factor kappa B pathway, Toll-like receptor pathway, transforming growth factor-ß (TGF-ß) pathway, and peroxisome proliferators activated receptor (PPAR) pathways. In this review, the literature about health benefits of fish consumption are accumulated from PubMed, Google Scholar, Scopus, and the mechanistic action of health benefits are summarized. Fish consumption at least twice per week as part of a healthy diet is beneficial for a healthy heart. More advances in this field could pose fish as a major nutrients source of foods.


Assuntos
Ácidos Graxos Ômega-3 , Óleos de Peixe , Animais , Ácidos Graxos Insaturados , Peixes/metabolismo , Humanos , NF-kappa B/metabolismo , Transdução de Sinais
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