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2.
Braz. j. biol ; 83: e245199, 2023. tab, graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1355853

RESUMO

Abstract The present investigation was aimed to examine the concentrations of trace metals including e.g copper (Cu), manganese (Mn), nickel (Ni), and zinc (Zn) in water samples collected from nursery pond of grass carp (Ctenopharyngodon idella) in Bannu Hatchery of Khyber Pakhtunkhwa during the period from April 2018 to January 2019. The temperature and pH of each water sample were measured for the whole study duration. The concentration of Copper (Cu), Manganese (Mn), Nickel (Ni), and Zinc (Zn) in collected water samples were measured in mg/liter by using Atomic Absorption Spectrophotometer. The blank and standard solutions for device calibration Standard solutions i.e., 2.0 mg, 4.0 mg, and 6.0 were used to measure the concentration of these metals in water samples to verify the measurements. The data was statistically analyzed on descriptive statistics (estimation of proportions and standard deviation) used to summarize mean concentration. The results obtained of both temperature and pH of water samples were found in ranged 10 to 36 0C and 7.0 to 8.44; whereas the size of fry stages was ranged from 4.0 to 56.0 mm in total length. The results of investigated metals found in pond water samples are in order of Zn>Mn>Ni>Cu, respectively. As optimum temperature and pH for grass carp were mostly between 15 0C and 30 0C and pH 6.5 to 8.0. It was concluded from obtained results that temperature, pH, and trace metals were found appropriate for the growth of Ctenopharyngodon idella from fry to fingerling stages, but the highest amount of zinc can cause its mortality. It is a preliminary study on grass carp culturing in Bannu fish hatchery so, it would provide useful information for model fish seed production unit in a hatchery.


Resumo A presente investigação teve como objetivo examinar as concentrações de metais traço, incluindo cobre (Cu), manganês (Mn), níquel (Ni) e zinco (Zn) em amostras de água coletadas de viveiro de carpa-capim (Ctenopharyngodon idella) em Incubatório de Bannu de Khyber Pakhtunkhwa durante o período de abril de 2018 a janeiro de 2019. A temperatura e o pH de cada amostra de água foram medidos durante todo o período do estudo. A concentração de cobre (Cu), manganês (Mn), níquel (Ni) e zinco (Zn) nas amostras de água coletadas foi medida em mg / litro usando espectrofotômetro de absorção atômica. As soluções em branco e padrão para as soluções padrão de calibração do dispositivo, ou seja, 2,0 mg, 4,0 mg e 6,0, foram usadas para medir a concentração desses metais em amostras de água para verificar as medições. Os dados foram analisados ​​estatisticamente em estatística descritiva (estimativa de proporções e desvio padrão) usada para resumir a concentração média. Os resultados obtidos tanto de temperatura quanto de pH das amostras de água variaram de 10 a 36 0C e 7,0 a 8,44, enquanto o tamanho dos estágios de alevinos variou de 4,0 a 56,0 mm no comprimento total. Os resultados dos metais investigados encontrados em amostras de água de lagoas são da ordem de Zn > Mn > Ni > Cu, respectivamente. A temperatura e o pH ótimos para a carpa-capim foram principalmente entre 15 0C e 30 0C e pH 6,5 a 8,0. Concluiu-se, a partir dos resultados obtidos, que temperatura, pH e traços de metais foram considerados adequados para o crescimento de Ctenopharyngodon idella desde os estágios de alevinos até alevinos, mas a maior quantidade de zinco pode causar sua mortalidade. É um estudo preliminar sobre a cultura da carpa-capim em incubatório de peixes Bannu, portanto forneceria informações úteis para modelo de unidade de produção de sementes de peixes em um incubatório.


Assuntos
Animais , Carpas , Paquistão , Água , Lagoas , Pesqueiros
3.
Braz. j. biol ; 83: e244494, 2023. tab, graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1285607

RESUMO

Abstract Since water is one of the essentials for life, the presence and quality of water in the habitat is extremely important. Therefore, water quality change and management of Lake Aygır was investigated in this study. For this, water samples collected from the lake and the irrigation pool between May 2015 and May 2016 were analyzed monthly. Spectrophotometric, titrimetric and microbiological methods were used to determine the water quality. According to some water quality regulations, HCO3, NH4, Cu, Mo, Br, fecal coliform and total suspended solid (TSS) values were found above the limit values. The other 29 parameters comply with Turkish national and international legislations. Lake Aygır was negatively affected by the surrounding settlements and agricultural activities. It is thought that the water resource should be monitored periodically and remedial studies should be done to prevent parameters exceeding the limits. However, Lake Aygır was generally suitable for drinking, use, fishing and irrigation.


Resumo Como a água é um dos elementos essenciais para a vida, a presença e a qualidade da água no habitat são extremamente importantes. Portanto, a mudança da qualidade da água e a gestão do lago Aygır foram investigadas neste estudo. Para isso, amostras de água coletadas no lago e na piscina de irrigação entre maio de 2015 e maio de 2016 foram analisadas mensalmente. Métodos espectrofotométricos, titulométricos e microbiológicos foram usados para determinar a qualidade da água. De acordo com alguns regulamentos de qualidade da água, os valores de HCO3, NH4, Cu, Mo, Br, coliformes fecais e total sólido suspenso (TSS) foram encontrados acima dos valores limite. Os outros 29 parâmetros estão em conformidade com as legislações nacionais e internacionais turcas. O lago Aygır foi afetado negativamente pelos assentamentos e atividades agrícolas ao redor. Pensa-se que o recurso hídrico deve ser monitorado periodicamente e estudos corretivos devem ser feitos para evitar que os parâmetros ultrapassem os limites. No entanto, o lago Aygır era geralmente adequado para beber, usar, pescar e irrigar.


Assuntos
Poluentes Químicos da Água/análise , Lagos , Turquia , Qualidade da Água , Monitoramento Ambiental , Pesqueiros
4.
Braz. j. biol ; 83: e246180, 2023. tab, graf
Artigo em Inglês | MEDLINE, LILACS, VETINDEX | ID: biblio-1278550

RESUMO

Abstract In fisheries, the phenomenon known as fishing down food webs is supposed to be a consequence of overfishing, which would be reflected in a reduction in the trophic level of landings. In such scenarios, the resilience of carnivorous, top predator species is particularly affected, making these resources the first to be depleted. The Serra Spanish mackerel, Scomberomorus brasiliensis, exemplifies a predator resource historically targeted by artisanal fisheries on the Brazilian coast. The present work analyzes landings in three periods within a 50-year timescale on the Parana coast, Southern Brazil, aiming to evaluate whether historical production has supposedly declined. Simultaneously, the diet was analyzed to confirm carnivorous habits and evaluate the trophic level in this region. Surprisingly, the results show that from the 1970's to 2019 Serra Spanish mackerel production grew relatively to other resources, as well as in individual values. The trophic level was calculated as 4.238, similar to other Scomberomorus species, consisting of a case where landings increase over time, despite the high trophic level and large body size of the resource. The results agree with a recent global assessment that has demystified a necessary correlation between high trophic level and overexploitation, but possible factors acting on the present findings are discussed.


Resumo Na pesca, o fenômeno fishing down food webs, ou 'pescando teias tróficas abaixo', expressa a redução do nível trófico na composição das capturas, e tem origem tradicionalmente atribuída à sobrepesca. Sob intenso extrativismo, a resiliência das espécies carnívoras, predadoras de topo, é particularmente afetada, sendo seus estoques os primeiros a entrarem em depleção. A cavala, ou serra, ou sororoca, Scomberomorus brasiliensis, é exemplo de recurso predador historicamente alvo da pesca artesanal, de pequena escala, na costa brasileira. O presente trabalho analisa os valores de desembarque do recurso em três períodos ao longo de 50 anos na costa paranaense, sul do Brasil, com objetivo de avaliar se sua produção tem efetivamente diminuído. Ainda, estuda-se a dieta da espécie na região, para confirmar seus hábitos carnívoros e avaliar o nível trófico na região. Os resultados mostram que, surpreendentemente, dos anos 1970 para 2019 a produção de S. brasiliensis tem aumentado em valores absolutos, bem como relativamente à de outros recursos, em que pese o nível trófico 4,238, similar a outras espécies do gênero. Constata-se que a pesca da cavala na região de estudo constitui um caso de aumento nos desembarques a despeito de elevado nível trófico e grande tamanho corpóreo. Os resultados concordam com recente levantamento em nível mundial, que nega existir correlação necessária entre sobrepesca e nível trófico alto, mas fatores que podem explicar os resultados do presente trabalho são discutidos.


Assuntos
Animais , Perciformes , Pesqueiros , Brasil , Conservação dos Recursos Naturais , Cadeia Alimentar
5.
Ying Yong Sheng Tai Xue Bao ; 33(3): 821-828, 2022 Mar.
Artigo em Chinês | MEDLINE | ID: mdl-35524537

RESUMO

Conservation of fish resources is the key to ecological protection and high-quality development of Yellow River basin. From 1960 to 2019, Yellow River basin distributed 201 fish species, belonging to 16 orders, 35 families. The species number of Cypriniformes was the largest (accounting for 60.7%), followed by Perciformes (accounting for 10.0%). From 1960 to 1980, there were 182 fish species belonging to 15 orders, 28 families. During 1980-2019, there were 112 species, belonging to 10 orders, 23 families. The total number of fish species in source area, midstream and downstream decreased significantly, while that in the upper reaches increased slightly. Jaccard's similarity index of source area, upstream, midstream and downstream between two periods were 34.2%, 46.0%, 42.4% and 35.7%, respectively. Based on feeding preference characteristic, fish species could be divided into eight feeding guilds: phytobenthivores, herbivores, phytoplanktivores, zooplanktivores, omnivorous, insectivores, zoobenthivores, and piscivores. Compared with the period from 1960 to 1980, the proportion of insectivores decreased significantly in the Yellow River basin during 1980-2019, while that of phytobenthivores, herbivores, phytoplanktivores, omnivorous and piscivores increased significantly. From 1960 to 1980, the proportion of insectivores was higher than other reaches at source area and upstream, then began to decrease along the river continuum from reaches with elevation of 2000-3000 m; while the proportion of piscivores was lower than other reaches at source area and upstream, then began to increase along the river continuum from reaches with elevation of 2000-3000 m. From 1980 to 2019, the proportion of insectivores decreased along river continuum from source area, and that of piscivores increased from source area to midstream but decreased in downstream. Development of cascade hydropower, water pollution, insufficient water flow, overfishing and invasion of alien fish were important factors causing the spatiotemporal variations of fish feeding guilds in Yellow River basin.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Animais , China , Peixes , Humanos , Rios
6.
PLoS One ; 17(5): e0267761, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35594271

RESUMO

Siphonophores (Cnidaria: Hydrozoa) are abundant and diverse gelatinous predators in open-ocean ecosystems. Due to limited access to the midwater, little is known about the diets of most deep-dwelling gelatinous species, which constrains our understanding of food-web structure and nutrient flow in these vast ecosystems. Visual gut-content methods can rarely identify soft-bodied rapidly-digested prey, while observations from submersibles often overlook small prey items. These methods have been differentially applied to shallow and deep siphonophore taxa, confounding habitat and methodological biases. DNA metabarcoding can be used to assess both shallow and deep species' diets under a common methodological framework, since it can detect both small and gelatinous prey. We (1) further characterized the diets of open-ocean siphonophores using DNA metabarcoding, (2) compared the prey detected by visual and molecular methods to evaluate their technical biases, and (3) evaluated tentacle-based predictions of diet. To do this, we performed DNA metabarcoding analyses on the gut contents of 39 siphonophore species across depths to describe their diets, using six barcode regions along the 18S gene. Taxonomic identifications were assigned using public databases combined with local zooplankton sequences. We identified 55 unique prey items, including crustaceans, gelatinous animals, and fish across 47 siphonophore specimens in 24 species. We reported 29 novel predator-prey interactions, among them the first insights into the diets of nine siphonophore species, many of which were congruent with the dietary predictions based on tentilla morphology. Our analyses detected both small and gelatinous prey taxa underrepresented by visual methods in species from both shallow and deep habitats, indicating that siphonophores play similar trophic roles across depth habitats. We also reveal hidden links between siphonophores and filter-feeders near the base of the food web. This study expands our understanding of the ecological roles of siphonophores in the open ocean, their trophic roles within the 'jelly-web', and the importance of their diversity for nutrient flow and ecosystem functioning. Understanding these inconspicuous yet ubiquitous predator-prey interactions is critical to predict the impacts of climate change, overfishing, and conservation policies on oceanic ecosystems.


Assuntos
Hidrozoários , Animais , Conservação dos Recursos Naturais , Código de Barras de DNA Taxonômico , Dieta , Ecossistema , Pesqueiros , Cadeia Alimentar , Hidrozoários/anatomia & histologia , Comportamento Predatório
7.
Nat Commun ; 13(1): 2383, 2022 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-35504907

RESUMO

Historical ecology has revolutionized our understanding of fisheries and cultural landscapes, demonstrating the value of historical data for evaluating the past, present, and future of Earth's ecosystems. Despite several important studies, Indigenous fisheries generally receive less attention from scholars and managers than the 17th-20th century capitalist commercial fisheries that decimated many keystone species, including oysters. We investigate Indigenous oyster harvest through time in North America and Australia, placing these data in the context of sea level histories and historical catch records. Indigenous oyster fisheries were pervasive across space and through time, persisting for 5000-10,000 years or more. Oysters were likely managed and sometimes "farmed," and are woven into broader cultural, ritual, and social traditions. Effective stewardship of oyster reefs and other marine fisheries around the world must center Indigenous histories and include Indigenous community members to co-develop more inclusive, just, and successful strategies for restoration, harvest, and management.


Assuntos
Pesqueiros , Ostreidae , Animais , Ecologia , Ecossistema , Alimentos Marinhos
8.
Mar Environ Res ; 177: 105625, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35462230

RESUMO

Beachcast events, where a large number of seabird carcasses drift ashore, occur with irregular intervals. These events are due to specific situations where mass mortality of seabirds have occurred. Disentangling the cause of these events can provide valuable information on stressors impacting seabird populations. Following several mass mortality events involving gulls in northern Norway, an investigation of the probable cause of death was initiated. In total 75 dead gulls were collected at two occasions and necropsies were carried out. The findings from the necropsy of the gulls were consistent with drowning as the primary cause of death. Bycatch in coastal purse seine fishery was considered a potential cause of the mortality and monitoring of seabird bycatch in this fishery was thus initiated. The monitoring of fishing operations revealed that 10% of 91 fishing events observed led to bycatch, with a total of 32 bycaught seabirds. These bycatch events resulted in a total estimated bycatch rate of 0.356 (95% CI = 0.133-0.949) birds per haul. These findings are consistent with the hypothesis that the registered mortality events were caused by bycatch in the purse seine fishery. The highly episodic and unpredictable nature of these events makes it demanding to achieve solid estimates of the occurrence and extent of bycatch without a very high monitoring effort. Our study shows that systematic investigation following beachcast events can shed light on the occurrence of such extreme events.


Assuntos
Charadriiformes , Pesqueiros , Animais , Aves , Conservação dos Recursos Naturais , Noruega
9.
Sci Rep ; 12(1): 6544, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35449381

RESUMO

In 2018, the giant manta ray was listed as threatened under the U.S. Endangered Species Act. We integrated decades of sightings and survey effort data from multiple sources in a comprehensive species distribution modeling (SDM) framework to evaluate the distribution of giant manta rays off the eastern United States, including the Gulf of Mexico. Manta rays were most commonly detected at productive nearshore and shelf-edge upwelling zones at surface thermal frontal boundaries within a temperature range of approximately 20-30 °C. SDMs predicted highest nearshore occurrence off northeastern Florida during April, with the distribution extending northward along the shelf-edge as temperatures warm, leading to higher occurrences north of Cape Hatteras, North Carolina from June to October, and then south of Savannah, Georgia from November to March as temperatures cool. In the Gulf of Mexico, the highest nearshore occurrence was predicted around the Mississippi River delta from April to June and again from October to November. SDM predictions will allow resource managers to more effectively protect manta rays from fisheries bycatch, boat strikes, oil and gas activities, contaminants and pollutants, and other threats.


Assuntos
Elasmobrânquios , Rajidae , Animais , Oceano Atlântico , Espécies em Perigo de Extinção , Pesqueiros , Georgia , Estados Unidos
10.
Sci Rep ; 12(1): 6582, 2022 Apr 21.
Artigo em Inglês | MEDLINE | ID: mdl-35449439

RESUMO

Over the last century, many shark populations have declined, primarily due to overexploitation in commercial, artisanal and recreational fisheries. In addition, in some locations the use of shark control programs also has had an impact on shark numbers. Still, there is a general perception that populations of large ocean predators cover wide areas and therefore their diversity is less susceptible to local anthropogenic disturbance. Here we report on temporal genomic analyses of tiger shark (Galeocerdo cuvier) DNA samples that were collected from eastern Australia over the past century. Using Single Nucleotide Polymorphism (SNP) loci, we documented a significant change in genetic composition of tiger sharks born between ~1939 and 2015. The change was most likely due to a shift over time in the relative contribution of two well-differentiated, but hitherto cryptic populations. Our data strongly indicate a dramatic shift in the relative contribution of these two populations to the overall tiger shark abundance on the east coast of Australia, possibly associated with differences in direct or indirect exploitation rates.


Assuntos
Tubarões , Animais , Austrália , Pesqueiros , Genômica , Estudos Retrospectivos , Tubarões/genética
11.
Zootaxa ; 5092(5): 559-575, 2022 Jan 24.
Artigo em Inglês | MEDLINE | ID: mdl-35390825

RESUMO

Sea cucumber (bche-de-mer, Echinodermata: Holothuroidea) is one of the top internationally traded seafood varieties. Besides its direct nutritional benefits, it is continuously used in the traditional medicine in different areas and cultures in the world. This world-wide interest triggered various issues related to stocks declining and risks of species extinction. For these reasons, the current study was designed to provide molecular tools for accurate discrimination between two sea cucumber species that prevail the Mediterranean of these echinoderms in Egypt, that are Holothuria polii and H. sanctori. The power of three gene markers, i.e., 16S rDNA, 28S rDNA, and Histone H3 in achieving accurate DNA-based identification, as well as elucidating clear phylogenetic and genetic diversity differences between those two species was assessed. Among the three genes, 16S rDNA showed the highest potentials as genetic and phylogenetic species discrimination marker. Both 28S rDNA and H3 exhibited the least number of holothuroid reference sequences in the GenBank database. For genetic diversity within each species population, 16S rDNA exhibited the best potentials, followed by H3. 28S rDNA showed no genetic polymorphism at all. Moreover, the collective data of both H3 and 16S rDNA suggested a possible role of asexual reproduction behavior in H. sanctori in the reduction of genetic diversity, as a possible response to overfishing. Hence, the current research can recommend the simultaneous application of both 16S rDNA and H3 as accurate markers for genetic discrimination among H. polii, H. sanctori and other different holothuroid species.


Assuntos
Pepinos-do-Mar , Animais , Conservação dos Recursos Naturais , DNA Ribossômico , Pesqueiros , Marcadores Genéticos , Mar Mediterrâneo , Filogenia , Pepinos-do-Mar/classificação , Pepinos-do-Mar/genética
12.
PLoS One ; 17(4): e0265095, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35385498

RESUMO

The Florida Horse Conch, Triplofusus giganteus, one of the largest marine gastropods in the world, has been intensely exploited by shell collectors, curio dealers, and commercial harvest for over a century and is now in decline. Effective management of horse conch populations requires better data on commercial and recreational harvest intensities but also on the species' intrinsic capacity to recover. Here, we use stable oxygen and carbon isotope sclerochronology to investigate the horse conch's life history, including its maximum life span, growth rates, age at first spawning, and number of lifetime spawning seasons. The largest two shells studied (460 and 475 mm linear shell length) grew for 13 and 11 years, respectively. Growth curves for these shells, extrapolated out to the length of the record size shell (606 mm linear shell length) predict a maximum age of just 16 years. Carbon isotopes and field photographs of spawning females suggest that females mature relatively late in life. However, the largest horse conchs remaining in the wild are also smaller and younger than those studied here. Thus, the largest females left in the wild could have few lifetime spawning events. High fecundity can buffer horse conchs from overfishing but only if females reach spawning age and reproductive-age females are protected. Our study highlights the usefulness of stable isotope sclerochronology for characterizing the life histories of molluscan species now too uncommon to study through traditional mark and recapture approaches.


Assuntos
Conservação dos Recursos Naturais , Gastrópodes , Animais , Feminino , Pesqueiros , Florida , Cavalos , Reprodução , Estações do Ano
13.
PLoS One ; 17(4): e0266538, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35395031

RESUMO

The clam Ameghynomia antiqua is a highly important resource for fisheries due to its high catches volume. It is the bivalve mollusc with the highest fisheries landings from natural beds on the Pacific coast of southern South America; however, studies of the reproductive conditions of this species are scarce and date back many years. The object of the present work was to evaluate the reproductive characteristics of the species, analysing its gametogenic and gonadal cycle, and reproductive indices, in fishery locations that present the natural beds with the highest fisheries catches, as well as parasite loads in the species. The gonads of the individuals were sampled monthly over a year and classified into one of three states called: "in development", "ripe" and "spawned". Synchrony between the sexes was observed in the indicators of the Gonadosomatic Index and Condition Index in each of the locations, although no synchrony was observed between locations. In the gametogenic cycle, the "ripe" state was observed in females in spring-summer, followed by rapid recovery to new development of the gonads; in males the "ripe" state was observed throughout the year. It was observed that males entered the "spawned" state one month ahead of females. The presence of digenean parasites in the state of metacercariae was detected in the gonads and mantle. No significant differences were found in the prevalence or intensity of infection when analysed by sex and month. The metacercariae were identified, by sequencing of three DNA regions, as belonging to the clade shared by species of the genus Parvatrema and close to the Gymnophalloides; both these genera belong to the family Gymnophallidae of the superclass Digenea. Infection was observed to reduce the gonadal tissue, in some cases causing castration. This is the first record of the presence of these parasites of A. antiqua, with genetic identification at genus level. These results are relevant for act proper management of this resource, which is important for fishing.


Assuntos
Bivalves , Trematódeos , Animais , Bivalves/parasitologia , Feminino , Pesqueiros , Gônadas , Humanos , Masculino , Reprodução , Trematódeos/genética
14.
Int Marit Health ; 73(1): 10-19, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35380169

RESUMO

BACKGROUND: Small-scale fishing is one of the most precarious occupations, with high rates of threats and hazards. The present study was undertaken to evaluate the health hazards and safety issues of fishers involved in small-scale fisheries (SSF). MATERIALS AND METHODS: Fifty SSF fishers (n = 50) were surveyed by using a pre-tested questionnaire between October 2019 and March 2020 at the lower Meghna River in the northern tip of the Bay of Bengal, Bangladesh. RESULTS: Results revealed that 56% of SSF fishermen belong to a nuclear family, and 42% completed primary education. Forty per cent had an annual income of between 1,000 and 1,500 USD. Seventy-six per cent of fishermen were found to suffer from fever, and 72%, and 60% from diarrhoea and skin diseases over the last 5 years (2015-2020), respectively. During fishing, 78% of fishermen also suffered from red-eye problems, dizziness, and headache, and 68% struggled with musculoskeletal complaints during the last 5 years. Extreme cyclonic occurrences and sudden storms were experienced by 66% and 32% of fishermen, respectively, during the last 5 years. Local pharmacies were visited by 46% of fishermen for treatment due to ease of access. Sixty-four per cent of participants applied their local indigenous knowledge to treat health-related problems. Twenty-eight per cent and 32% of fishermen used a first aid box and stored medicine on board, respectively. CONCLUSIONS: Most of the fishers are in great risk of medium- to high-range danger while fishing in the SSF sector in Bangladesh. Many countries have developed protocols for safe and responsible fishing. In Bangladesh, adequate attention is needed for the sustainable development of the SSF sector.


Assuntos
Saúde do Trabalhador , Bangladesh , Emprego , Pesqueiros , Nível de Saúde , Humanos
15.
Sci Rep ; 12(1): 5600, 2022 04 04.
Artigo em Inglês | MEDLINE | ID: mdl-35379879

RESUMO

Small pelagic fishes in the Mediterranean Sea constitute about half of the total landings, of which almost one-third is European anchovy. Anchovy abundance mainly depends on early life stage and juvenile survival and growth, which are susceptible to shifts in environmental processes. Due to the commercial importance of this species, it is necessary to elucidate the processes affecting recruitment strength for effective fishery management, using environmental indices to set more appropriate harvesting limits. Here, we constructed a simple index to capture synchronicity between enrichment and retention/concentration processes, which are known to affect anchovy abundance, during the first year of life. Three ecosystems in the Mediterranean were examined: Gulf of Lions, Adriatic Sea, and Strait of Sicily. The synchronicity index (SI) represented the synergic evolution over time of the chlorophyll-a concentration (CHL, enrichment process) and mixed layer depth (MLD, concentration/retention processes), and was related with the abundance of anchovy recruits obtained from published survey reports. Considering different ecosystems, when the SI was significantly higher, anchovy recruitment was promoted. This result indicated SI is consistent across ecosystems in explaining anchovy abundance fluctuations and thus could be used to enhance fisheries management and extended to assess the impact of projected environmental changes.


Assuntos
Ecossistema , Peixes , Animais , Pesqueiros , Mar Mediterrâneo , Alimentos Marinhos
16.
Nat Commun ; 13(1): 1612, 2022 04 05.
Artigo em Inglês | MEDLINE | ID: mdl-35383162

RESUMO

Labor abuse on fishing vessels and illegal, unreported and unregulated (IUU) fishing violate human rights, jeopardize food security, and deprive governments of revenues. We applied a multi-method approach, combining new empirical data with satellite information on fishing activities and vessel characteristics to map risks of labor abuse and IUU fishing, understand their relationships, and identify major drivers. Port risks were globally pervasive and often coupled, with 57% of assessed ports associated with labor abuse or IUU fishing. For trips ending in assessed ports, 82% were linked to labor abuse or IUU fishing risks. At-sea risk areas were primarily driven by fishing vessel flags linked to poor control of corruption by the flag state, high ownership by countries other than the flag state, and Chinese-flagged vessels. Transshipment risk areas were related to the gear type of fishing vessels engaged in potential transshipment and carrier vessel flags. Measures at port offer promise for mitigating risks, through the Port State Measures Agreement for IUU fishing, and ensuring sufficient vessel time at port to detect and respond to labor abuse. Our results highlight the need for coordinated action across actors to avoid risk displacement and make progress towards eliminating these socially, environmentally and economically unsustainable practices.


Assuntos
Conservação dos Recursos Naturais , Pesqueiros , Humanos
17.
Artigo em Inglês | MEDLINE | ID: mdl-35409961

RESUMO

A majority of subsidence lakes were reclaimed as fish ponds, but the widespread use of antibiotics has caused the pollution of antibiotic resistance genes (ARGs). This paper uses zeolite as a filter material to construct a horizontal submersible wastewater treatment device and explores its effect on the removal of conventional pollutants and sulfonamide ARGs in wastewater. The results showed that the removal of total nitrogen and ammonia nitrogen by the zeolite filter media were 59.0% and 63.8%, respectively, which were higher than the removal of total phosphorus and COD. The absolute abundances of sul1 and sul2 in wastewater were 2.81 × 104 copies·L-1 and 2.42 × 103 copies·L-1. On average, 60.62% of sul1 and 75.84% of sul2 can be removed, and more than 90% of sul1 and sul2 can be removed. Experiments showed that the residence time of wastewater in the treatment device had a significant impact on removal. The microbial community structure of aquaculture wastewater was quite different before and after wastewater treatment. The abundance changes of Saccharimonadales and Mycobacterium affect the removal of sulfonamide ARGs.


Assuntos
Águas Residuárias , Zeolitas , Animais , Antibacterianos , Pesqueiros , Genes Bacterianos , Nitrogênio , Sulfonamidas , Águas Residuárias/microbiologia
18.
Artigo em Inglês | MEDLINE | ID: mdl-35410026

RESUMO

Recreational fishing and other outdoor recreational activities have been proven to have positive effects on mental health, including neutralizing pandemic stress. This study aims to identify the perceptions and behavior of recreational anglers during the COVID-19 pandemic along with identifying the factors that determine attitudes. This study is essential for understanding the complex economic, social, and environmental implications associated with a pandemic. Perceptions of pandemic stress reduction were confirmed by 63.8% of anglers, and nearly 98% felt there was no risk of infection from fishing. These feelings were most strongly positively associated and explained by a preference for fishing with friends and family and the frequency of fishing. Over 26% of respondents fished more frequently during the pandemic. Additional free time and the need to escape the pandemic media hype were the main factors for the increase in angler activity. The balance of benefits from changes in angler pandemic behavior was ambiguous. This was determined by considering the potential increase in pressure on the environmental resources that anglers use. Given the positive effects of angling on stress reduction, it is not advisable for policymakers to restrict recreational fishing access. Instead, best management practices should reduce sanitary bottlenecks to increase safety on fishing grounds.


Assuntos
COVID-19 , Pesqueiros , COVID-19/epidemiologia , Humanos , Pandemias/prevenção & controle , Recreação , Fatores Socioeconômicos
19.
Environ Manage ; 69(6): 1102-1117, 2022 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-35435475

RESUMO

Fisheries compliance has been explored conceptually and empirically in numerous contexts but in many fisheries, compliance with rules is not sufficient to return to sustainable levels of effort. Failing to understand the context and what drives fishers to behave the way they do, has the potential to misdirect investments. The authors present a conceptual model of fisheries ecosystem stewardship (FES) that expands upon fisheries compliance with the addition of moral obligation for fishing communities. This paper uses household survey data from fishing communities in three marine key biodiversity areas (MKBA) in the Philippines to test part of the FES model using logistic regression and multiple regression analysis with empirical data to test the model. Data shows that apart from the respondents' location (i.e., which MKBA is adjacent to their community), knowledge of laws protecting coastal/marine resources was the most important predictor of environmental stewardship, followed by support for limiting fishing effort and knowledge of illegal fishing. Individual decisions about if and how-to fish are influenced by the economic context and available livelihood opportunities. However, the moral obligation to "do the right thing" is equally, if not more important to consider for fisheries ecosystem stewardship in fishing communities.


Assuntos
Ecossistema , Pesqueiros , Animais , Conservação dos Recursos Naturais , Peixes , Filipinas
20.
Mar Pollut Bull ; 178: 113603, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35390629

RESUMO

To assess the aquaculture-induced sediment conditions associated with sulfur cycles, shifts in bacterial communities across farming stages were investigated. The sulfate reduction rate (SRR), and concentrations of acid volatile sulfide (AVS) and H2S were significantly higher at the mid- and post-farming stages than at the early stage, indicating that the aquaculture effects persist even after harvest. Incomplete organic carbon-oxidizing sulfate-reducing bacteria (IO-SRB) affiliated with Desulfobulbaceae, and gammaproteobacterial sulfur oxidizing bacteria (SOB) (Thiohalobacter, Thioprofundum, and Thiohalomonas) were dominant during the early stage, whereas fermenting bacteria (Bacteroidetes and Firmicutes) and complete oxidizing SRB (CO-SRB) belonging to Desulfobacteraceae, and epsilonproteobacterial SOB (Sulfurovum) dominated during the mid- and post-stages. The shift in SRB and SOB communities well reflected the anoxic and sulfidic conditions of farm sediment. Especially, the Sulfurovum-like SOB correlated highly and positively with H2S, AVS, and SRR, suggesting that they could be relevant microbiological proxies to assess sulfidic conditions in farm sediment.


Assuntos
Bactérias , Pesqueiros , Sulfatos , Sulfetos , Enxofre
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