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1.
Chemosphere ; 262: 127879, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-32781334

RESUMO

The collapse of the Fundão Dam, in Southeastern Brazil, caused about 50 million m³ of iron ore tailings to sluice down the mountain to Rio Doce, in what is considered the greatest environmental disaster in Brazilian history. The fluvial system received an intense and sudden mudflow that was transported for more than 650 km, before reaching the Atlantic Ocean. Because the area was already impacted by the mineral activities in the region, it becomes essential to evaluate the environmental conditions before the disaster to correctly assess the disaster real damage. This study compares the concentration of trace metals in the sediments of the Rio Doce alluvial plain, before and after the dam collapse, as well as the newly deposited iron ore tailings that became part of the sedimentary framework. The data indicate that the fine particles deposited have since been incorporated into the sandy river sediments. The cadmium and arsenic contents in the sediments increased to levels above the National Environment Council thresholds. The comparison between the levels of trace metals in the situations before and after disaster shows that the mining mud is the source of cadmium while the arsenic was present before the environmental disaster, and its concentration increased due to sediment remobilization. The iron ore tailings deposited on the alluvial sediments also affected the physical parameters since the formed ferruginous crusts waterproofed the ground surface and may, gradually, release toxic metals when exposed to weathering and river reworking.


Assuntos
Monitoramento Ambiental , Metais/análise , Mineração , Poluentes Químicos da Água/análise , Oceano Atlântico , Brasil , Desastres , Ferro , Compostos de Ferro , Minerais , Rios , Colapso Estrutural , Oligoelementos
2.
Sci Total Environ ; 751: 141453, 2021 Jan 10.
Artigo em Inglês | MEDLINE | ID: mdl-32882547

RESUMO

Trace metals such as Cu, Hg, and Zn have been widely investigated in marine ecotoxicological studies considering their bioaccumulation, transfer along trophic webs, and the risks they pose to ecosystems and human health. Comparatively, Li has received little attention, although this element is increasingly used in the high-tech, ceramics/glass, and medication industries. Here, we report Li concentrations in more than 400 samples, including whole organisms and different organs of bivalves, cephalopods, crustaceans, and fish. We investigated species from three contrasting biogeographic areas, i.e. temperate (Bay of Biscay, northeast Atlantic Ocean), tropical (New Caledonia, Pacific Ocean), and subpolar climates (Kerguelen Islands, southern Indian Ocean), among diverse trophic groups (filter-feeders to meso-predators) and habitats (benthic, demersal, and pelagic). Although Li is homogeneously distributed in the ocean (at 0.18 µg/mL), Li concentrations in soft tissues vary greatly, from 0.01 to 1.20 µg/g dry weight. Multiple correspondence analyses reveal two clusters of high and low Li concentrations. Li distributions in marine organisms appear to be mostly geographically independent, though our results highlight a temperature dependency in fish muscles. Li is consistently bio-reduced through the trophic webs, with filter-feeders showing the highest concentrations and predatory fish the lowest. Strong variations are observed among organs, consistent with the biochemical similarity between Na and Li during transport in the brain and in osmoregulatory organs. Fish gills and kidneys show relatively high Li concentrations (0.26 and 0.15 µg/g, respectively) and fish brains show a large range of Li contents (up to 0.34 µg/g), whereas fish liver and muscles are Li depleted (0.07 ± 0.03 and 0.06 ± 0.08 µg/g, respectively). Altogether, these results provide the first exhaustive baseline for future Li ecotoxicology studies in marine coastal environments.


Assuntos
Organismos Aquáticos , Poluentes Químicos da Água , Animais , Oceano Atlântico , Ecossistema , Monitoramento Ambiental , Peixes , Cadeia Alimentar , Humanos , Oceano Índico , Lítio , Nova Caledônia , Oceano Pacífico , Inquéritos e Questionários , Poluentes Químicos da Água/análise
3.
Mar Pollut Bull ; 160: 111659, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33181936

RESUMO

Tubastraea coccinea Lesson, 1830 and T. tagusensis Wells 1982 are azooxanthellate corals non-native to Brazil and introduced through fouling on oil platforms, the primary vector. They first invaded the tropical rocky reefs at Ilha Grande Bay (southwest Atlantic Ocean), during the early 1990s. Currently, at some Brazilian locations these species occupy 80% of the benthos of the shallow subtidal. They cause economic and environmental impacts by fouling shipping and modifying native communities. This study provides observations of an additional mechanism of secondary dispersal by T. coccinea and T. tagusensis that were seen attached to floating wood debris and marine litter, which are highly abundant in the region. Such rafting corals have been found adjacent to invaded reefs and stranded on beaches. These observations indicate that transport by rafting over long distances may be another mechanism of range expansion and secondary introduction of these invasive species within the region.


Assuntos
Antozoários , Animais , Oceano Atlântico , Brasil , Ecossistema , Espécies Introduzidas , Madeira
4.
Science ; 370(6517): 662-663, 2020 11 06.
Artigo em Inglês | MEDLINE | ID: mdl-33154126
5.
An Acad Bras Cienc ; 92(suppl 2): e20180933, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33084748

RESUMO

During a parasitological survey of the olfactory sacs of 21 species of Rajiformes (Chondrichthyes) from the Southwestern Atlantic Ocean, copepods referable to Dendrapta Kabata (1964) (Siphonostomatoida: Lernaeopodidae) were found parasitizing the cuphead skate Bathyraja scaphiops (Rajiformes: Arhynchobatidae). Morphological analyses using both light and electron microscopy revealed that they belong to a new species. It can be easily distinguished from its congeners by the ratio between lengths of posterior process and trunk (1:0.8), the large to width ratio of trunk (1:0.7) and the armature of the antennule (1, 1, 5 + 1 aesthete). Dendrapta cameroni longiclavata is raised to full specific status, as Dendrapta longiclavata n. comb. Kabata & Gusev, 1966.


Assuntos
Copépodes , Parasitos , Rajidae , Trematódeos , Animais , Oceano Atlântico
6.
Med Sci (Paris) ; 36(10): 945-948, 2020 Oct.
Artigo em Francês | MEDLINE | ID: mdl-33026341

RESUMO

More than 10 million enslaved Africans were transported to the Americas between 1500 and 1900. Recent genetic studies investigate regional African ancestry components in present-day Africa-Americans, and allow comparison with the extensive records documenting these deportations. The genetic evidence generally agrees with the historical records but brings additional insights in this dark episode of human history.


Assuntos
Afro-Americanos/genética , Pessoas Escravizadas , Escravização/história , Genética Populacional , África , Oceano Atlântico , Comércio/história , DNA Mitocondrial/análise , DNA Mitocondrial/genética , Pessoas Escravizadas/história , Fluxo Gênico/fisiologia , Variação Genética , História do Século XVI , História do Século XVII , História do Século XVIII , História do Século XIX , Humanos , Padrões de Herança/genética , Estados Unidos
7.
Zootaxa ; 4786(3): zootaxa.4786.3.2, 2020 Jun 03.
Artigo em Inglês | MEDLINE | ID: mdl-33056471

RESUMO

The present study deals with two species new to science, as well as several new records in the closely related alpheid shrimp genera Salmoneus Holthuis, 1955 and Deioneus Dworschak, Anker Abed-Navandi, 2000, based on material collected at various localities in the tropical western and eastern Atlantic Ocean. In the western Atlantic, Salmoneus inconspicuus sp. nov. is described based on material from the Caribbean coast of Panama, Cuba, French Antilles and (with some doubts) Bermuda. The new species has been previously reported from the eastern Caribbean Sea as S. teres Manning Chace, 1990, a closely related species so far known only from Ascension Island in the central Atlantic. Salmoneus camaroncito Anker, 2010 is reported from the Caribbean coast of Mexico, for the first time since its original description. Salmoneus carvachoi Anker, 2007 is reported from Colombia and southeastern USA, representing a new record of the species for each of these countries. Salmoneus depressus Anker, 2011 and Salmoneus setosus Manning Chace, 1990 are reported for the first time from Cuba and Panama, respectively. In addition, these two species, as well as Salmoneus wehrtmanni Anker, 2010, are reported from new localities in Mexico. In the eastern Atlantic, Salmoneus saotomensis sp. nov. is described based on a single specimen from São Tomé Island in the Gulf of Guinea. The new species is characterised by the somewhat enlarged minor cheliped and is compared to all other Atlantic species presenting this feature. Deioneus sandizelli Dworschak, Anker Abed-Navandi, 2000 is reported from São Tomé Island, for the first second time since its original description based on the Cape Verde type material. The characters separating Deioneus and Salmoneus are reassessed. The new evidence shows that these two genera are distinguished by only one morphological feature known to be variable in at least one non-related alpheid genus. However, in view of the increasing morphological heterogeneity in Salmoneus, it seems more appropriate to retain Deioneus as a valid genus for it may represent a distinct clade that also includes several other species currently placed in Salmoneus.


Assuntos
Decápodes , Distribuição Animal , Estruturas Animais , Animais , Oceano Atlântico
8.
Zootaxa ; 4852(2): zootaxa.4852.2.4, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33056424

RESUMO

Two new species of miniature silverside fishes are described from coastal habitats in the tropical Atlantic: Membras pygmaea sp. nov., from Brus Lagoon, Honduras, and M. procera sp. nov., from the Gulf of Urabá, Colombia. These new species belong to the martinica species-group within the genus Membras Bonaparte. The monophyletic martinica species-group (see below) contains four additional species, all coastal, marine that extend from the east coast of North America to São Paolo State, Brazil. Within the martinica species-group, all but M. martinica are miniature species, ranging from 41-60 mm SL. The smallest species, M. pygmaea sp. nov., is mature at 24 mm SL. A geometric morphometric analysis shows: (i) each species of the martinica species-group occupies its own portion of shape space; and (ii) none of the miniature species possess the shapes of small immature M. martinica. While some of the literature suggests that miniaturization may involve paedomorphosis, our results show that the miniatures accelerate to adult body forms.


Assuntos
Peixes , Animais , Oceano Atlântico
9.
Zootaxa ; 4763(4): zootaxa.4763.4.3, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-33056844

RESUMO

Four new species of Pseudharpinia Schellenberg, 1931 are described. The material examined was collected during the Mini Biological Trawl project, off Atlantic's southwestern coast on the states of Rio de Janeiro, São Paulo, Santa Catarina and Rio Grande do Sul with rectangular dredges at 25 to 500 meters depth. All the new species described present the following remarkable character states that make them easily distinguishable from their congeners: P. bonhami sp. nov. has pereopod 7 basis with 6 large spines posteroventrally; P. jonesyi sp. nov. exhibits pereopod 6 basis with a long acute spiny-projection posteriorly; P. pagei sp. nov. presents head with ventrolateral lines, antenna 1 primary flagellum with stout article 1, gnathopod 2 palm excavate and with slightly serrate palmar hump; P. planti sp. nov. presents head with dorsal keel and ventrolateral line, elongate flagella article 1 of antenna 1, pereopods 3-4 carpus anterior margin with a comb-like structure distally and pereopod 7 merus strongly produced posteroventrally. An identification key for all species of Pseudharpinia of the world is provided.


Assuntos
Anfípodes , Animais , Oceano Atlântico
10.
PLoS One ; 15(9): e0238914, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32946472

RESUMO

The Atlantic Forest is considered the fourth most important biodiversity hotspot. Although almost 96% of its original area has been devastated, a large part of its remaining conserved area is inhabited by traditional communities. This research focused on two Quilombola communities who reside within the Núcleo Picinguaba of the Serra do Mar State Park, State of São Paulo, Brazil. The objective was to use a combination of ethnoecological and ecological approaches to select priority species for which to develop participatory conservation and sustainable management plans in protected areas in Brazil. We collaborated with community members to collect ethnobotanical and ethnoecological data and then measured the abundance of native species in local forests through phytosociological sampling. We used this information to assess the degree of threat to useful species using the Conservation Priority Index, adding an additional layer of analysis based on habitat successional categories. We then overlayed those useful species identified as highest risk locally with those federally listed as threatened or endangered. Based on this, we identified three species as priority for the development of sustainable management plans: Virola bicuhyba, Cedrella fissilis and Plinia edulis.


Assuntos
Conservação dos Recursos Naturais/métodos , Espécies em Perigo de Extinção/estatística & dados numéricos , Magnoliopsida/crescimento & desenvolvimento , Oceano Atlântico , Brasil/etnologia , Ecossistema , Etnobotânica , Florestas , Humanos , Magnoliopsida/classificação
11.
Environ Pollut ; 265(Pt A): 114721, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32806407

RESUMO

Microplastic debris is ubiquitous and yet sampling, classifying and enumerating this prolific pollutant in marine waters has proven challenging. Typically, waterborne microplastic sampling is undertaken using nets with a 333 µm mesh, which cannot account for smaller debris. In this study, we provide an estimate of the extent to which microplastic concentrations are underestimated with traditional sampling. Our efforts focus on coastal waters, where microplastics are predicted to have the greatest influence on marine life, on both sides of the North Atlantic Ocean. Microplastic debris was collected via surface trawls using 100, 333 and 500 µm nets. Our findings show that sampling using nets with a 100 µm mesh resulted in the collection of 2.5-fold and 10-fold greater microplastic concentrations compared with using 333 and 500 µm meshes respectively (P < 0.01). Based on the relationship between microplastic concentrations identified and extrapolation of our data using a power law, we estimate that microplastic concentrations could exceed 3700 microplastics m-3 if a net with a 1 µm mesh size is used. We further identified that use of finer nets resulted in the collection of significantly thinner and shorter microplastic fibres (P < 0.05). These results elucidate that estimates of marine microplastic concentrations could currently be underestimated.


Assuntos
Plásticos , Poluentes Químicos da Água/análise , Oceano Atlântico , Monitoramento Ambiental , Microplásticos
12.
PLoS One ; 15(8): e0237819, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32822424

RESUMO

Besides understanding the effects of fishing on harvested fish stocks, effects on non-target species, habitats and seafloor integrity also need to be considered. Static fishing gears have often been mentioned as a lower impact fishing alternative to towed gears, although studies examining their actual impact on the seafloor are scarce. In this study, we aimed to describe fish trap movements on the seafloor related to soaking time and trap retrieval. Impacts on the seafloor of lightweight rectangular traps and heavier circular traps were compared. We used 3D video cameras to estimate sweeping motion on the seabed and penetration into the sediment during soaking time. The area and distance swept by each type of trap during retrieval was determined by a camera set up facing the sea bottom. The potential rotation of the traps around the mainline was assessed using an Acoustic Doppler Current Profiler. Results showed that no penetration and almost no movements could be detected during soaking time for either lightweight or heavy commercial traps, even for high tidal coefficient (maximum 6 cm). No rotation could be observed when the tide turned. The swept area covered by a trap during retrieval was low (maximum 2.04 m2) compared to towed fishing gear and other static gear.


Assuntos
Conservação dos Recursos Naturais/métodos , Pesqueiros , Animais , Oceano Atlântico , Ecossistema , Peixes , Biologia Marinha
13.
Mar Pollut Bull ; 158: 111441, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32736204

RESUMO

Ostreopsis is a benthic dinoflagellate genus comprising eleven species including seven that are toxigenic. Ostreopsis lenticularis was first described from French Polynesia and is widely distributed in many insular locations from the Pacific Ocean. The current study presents morphological and molecular evidence of the presence of O. lenticularis at the Fernando de Noronha Archipelago, South Atlantic. Light microscopy and scanning electron microscopy of field cells showed morphological features in agreement with the description of O. lenticularis. Cells were broadly oval, 66.0-117.5 µm in dorso-ventral diameter, 50.0-92.5 µm in width, with thecal plates presenting two kinds of pores. Phylogenetic analyses based on LSU (D1-D3) and ITS sequences from field cells from Fernando de Noronha clustered with O. lenticularis sequences from elsewhere. The species was present in low to high abundances. The current study expands the distribution of O. lenticularis to Fernando de Noronha Archipelago in the South Atlantic Ocean.


Assuntos
Dinoflagelados , Oceano Atlântico , Oceano Pacífico , Filogenia , Polinésia
14.
Mar Pollut Bull ; 158: 111431, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32736205

RESUMO

Since 2011, huge amounts of Sargassum algae are detected in the equatorial Atlantic, causing large strandings events on the coasts of the West Indies, Brazil and West Africa. The distribution of this stock shows strong annual and interannual variability, whose drivers are not settled yet. Here we use satellite Sargassum observations from MODIS and currents from an ocean reanalysis to simulate the passive transport of algae in 2017. Wind effect was necessary to fit the observed distribution. Simulations reasonably reproduce the satellite monthly distribution for up to seven months, confirming the prominent role of transport in the distribution cycle. Annual cycle appears as a zonal exchange between eastern (EAR) and western accumulation regions (WAR). EAR is well explained by advection alone, with sharp meridional distribution controlled by converging currents below the inter-tropical Convergence Zone. Instead, WAR is not explained by advection alone, suggesting local growth.


Assuntos
Sargassum , Oceano Atlântico , Brasil , Índias Ocidentais , Vento
15.
Mar Pollut Bull ; 158: 111394, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32753180

RESUMO

The invasive coral Tubastraea tagusensis (sun coral) is a habitat-forming species currently increasing its geographical range into the Atlantic Ocean, thereby causing negative ecological and socioeconomic impacts. Scuba divers observed this coral in the western equatorial Atlantic in January 2020, growing at high densities on a shipwreck from World War II (sunk in 1943) at a depth of approximately 32 m. Available footage from the beginning of the decade (2012-2018) shows no obvious signs of sun coral on this shipwreck, suggesting recent colonization and range expansion. The recent evidence of expansion was found 200 km east of the last record, which was also found on a WWII shipwreck (sunk in 1942) in 2016. We have identified hundreds of overlooked WWII shipwrecks, as well as new wrecks in shallow and mesophotic waters, that may provide stepping-stone habitats for this coral to expand its distribution in the Atlantic. We discuss the role of shipwrecks as a network of stepping stones for the sun coral spread, creating complementary paths for the invasiveness by overcoming physiological traits and the short lifespan of the coral larvae. Previous research underestimates the importance of these artificial stepping-stone patches in sustaining crucial dispersal events and range expansion of invasive species. These results are a call to action to manage the invasive Tubastraea corals at a national and international scale in the Atlantic basin.


Assuntos
Antozoários , Animais , Oceano Atlântico , Recifes de Corais , Ecossistema , Espécies Introduzidas
16.
Int J Food Microbiol ; 333: 108812, 2020 Nov 16.
Artigo em Inglês | MEDLINE | ID: mdl-32805575

RESUMO

The aim of this study was to evaluate the occurrence, infection level and distribution of ascaridoid larvae in cephalopod products sold in Italy. Data on the species most commonly commercialized as whole and fresh on the Italian market were collected. After comparing commercial and literature data, Eledone spp., comprising E. cirrhosa and E. moschata (horned octopus and musky octopus, respectively) and Doryteuthis pealeii (longfin inshore squid) were selected, as they had been rarely investigated. Overall, 75 Eledone spp. caught in the Mediterranean Sea (FAO area 37) and 70 D. pealeii from the Northwest Atlantic Ocean (FAO area 21) were examined by visual inspection and artificial digestion (viscera and mantle separately). Parasites were submitted to morphological and molecular analysis. Prevalence (P), mean intensity (MI) and mean abundance (MA) were calculated. In D. pealeii, 2 nematode larvae molecularly identified as Anisakis simplex s.s. were found in the viscera and in the mantle of two specimens (P: 2.9% 95% CI: 0-6.8%; MI: 1; MA: 0.028). In Eledone spp. 9 nematode larvae molecularly attributed to Hysterothylacium spp. were found in the mantle of 5 specimens (P: 6.7% 95% CI: 1-12.3%; MI: 1.8; MA: 0.12). This is the first report of A. simplex s.s. in D. pealeii. Considering the zoonotic and allergenic potential of these larvae and their localization also in the edible part (mantle), a potential public health issue exists.


Assuntos
Anisaquíase/veterinária , Anisakis/isolamento & purificação , Decapodiformes/parasitologia , Octopodiformes/parasitologia , Alimentos Marinhos/parasitologia , Animais , Anisaquíase/parasitologia , Anisakis/classificação , Oceano Atlântico , Peixes/parasitologia , Parasitologia de Alimentos , Itália , Larva , Mar Mediterrâneo
17.
PLoS One ; 15(8): e0237704, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32804963

RESUMO

Since plastics degrade very slowly, they remain in the environment on much longer timescales than most natural organic substrates and provide a novel habitat for colonization by bacterial communities. The spectrum of relationships between plastics and bacteria, however, is little understood. The first objective of this study was to examine plastics as substrates for communities of Bacteria in estuarine surface waters. We used next-generation sequencing of the 16S rRNA gene to characterize communities from plastics collected in the field, and over the course of two colonization experiments, from biofilms that developed on plastic (low-density polyethylene, high-density polyethylene, polypropylene, polycarbonate, polystyrene) and glass substrates placed in the environment. Both field sampling and colonization experiments were conducted in estuarine tributaries of the lower Chesapeake Bay. As a second objective, we concomitantly analyzed biofilms on plastic substrates to ascertain the presence and abundance of Vibrio spp. bacteria, then isolated three human pathogens, V. cholerae, V. parahaemolyticus, and V. vulnificus, and determined their antibiotic-resistant profiles. In both components of this study, we compared our results with analyses conducted on paired samples of estuarine water. This research adds to a nascent literature that suggests environmental factors govern the development of bacterial communities on plastics, more so than the characteristics of the plastic substrates themselves. In addition, this study is the first to culture three pathogenic vibrios from plastics in estuaries, reinforcing and expanding upon earlier reports of plastic pollution as a habitat for Vibrio species. The antibiotic resistance detected among the isolates, coupled with the longevity of plastics in the aqueous environment, suggests biofilms on plastics have potential to persist and serve as focal points of potential pathogens and horizontal gene transfer.


Assuntos
Biofilmes/efeitos dos fármacos , Estuários , Plásticos , Vibrio/isolamento & purificação , Poluentes da Água , Antibacterianos/farmacologia , Oceano Atlântico , DNA Bacteriano/isolamento & purificação , Farmacorresistência Bacteriana/genética , Transferência Genética Horizontal , RNA Ribossômico 16S/genética , Água do Mar/microbiologia , Vibrio/efeitos dos fármacos , Vibrio/genética
18.
PLoS One ; 15(7): e0235963, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722700

RESUMO

The impacts of changes in climate are often most readily observed through the effects of extremes in local weather, effects that often propagate through multiple ecosystem levels. Precise effects of any extreme weather event depend not only on the type of event and its timing, but also on the ecosystem affected. Here the cascade of effects following the arrival of an atmospheric river (directed by record-breaking Storm Desmond) across terrestrial, freshwater and coastal zones is quantified, using the Burrishoole system on the Atlantic coast of Ireland as a natural observatory. We used a network of high-frequency in-situ sensors to capture in detail the effects of an unprecedented period of rainfall, high wind speeds and above-average winter air temperatures on catchment and estuarine dynamics. In the main freshwater lake, water clarity decreased and acidity increased during Storm Desmond. Surface heat input, due to a warm and moist above-lake air mass, was rapidly distributed throughout the water column. River discharge into the downstream coastal basin was estimated to be the highest on record (since 1976), increasing the buoyancy flux by an order of magnitude and doubling the water column stratification stability. Entrainment of salt into the outflowing freshwater plume exported resident salt from the inner estuarine basin, resulting in net salt loss. Here, the increased stratification markedly reinforced isolation of the bottom waters, promoting deoxygenation. Measurements of current between the inner estuarine basin and the adjacent coastal waters indicated a 20-fold increase in the volume of seaward flowing low-salinity water, as a result of storm rainfall over the watershed. Storm impacts spanned the full catchment-to-coast continuum and these results provide a glimpse into a potential future for hydrological systems where these severe hydroclimatic events are expected to occur more frequently.


Assuntos
Mudança Climática , Ecossistema , Monitoramento Ambiental/métodos , Modelos Teóricos , Estações do Ano , Tempo (Meteorologia) , Oceano Atlântico , Área Programática de Saúde , Humanos
19.
PLoS One ; 15(7): e0234075, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32678823

RESUMO

Ocean acidification (OA) represents a serious challenge to marine ecosystems. Laboratory studies addressing OA indicate broadly negative effects for marine organisms, particularly those relying on calcification processes. Growing evidence also suggests OA combined with other environmental stressors may be even more deleterious. Scaling these laboratory studies to ecological performance in the field, where environmental heterogeneity may mediate responses, is a critical next step toward understanding OA impacts on natural communities. We leveraged an upwelling-driven pH mosaic along the California Current System to deconstruct the relative influences of pH, ocean temperature, and food availability on seasonal growth, condition and shell thickness of the ecologically dominant intertidal mussel Mytilus californianus. In 2011 and 2012, ecological performance of adult mussels from local and commonly sourced populations was measured at 8 rocky intertidal sites between central Oregon and southern California. Sites coincided with a large-scale network of intertidal pH sensors, allowing comparisons among pH and other environmental stressors. Adult California mussel growth and size varied latitudinally among sites and inter-annually, and mean shell thickness index and shell weight growth were reduced with low pH. Surprisingly, shell length growth and the ratio of tissue to shell weight were enhanced, not diminished as expected, by low pH. In contrast, and as expected, shell weight growth and shell thickness were both diminished by low pH, consistent with the idea that OA exposure can compromise shell-dependent defenses against predators or wave forces. We also found that adult mussel shell weight growth and relative tissue mass were negatively associated with increased pH variability. Including local pH conditions with previously documented influences of ocean temperature, food availability, aerial exposure, and origin site enhanced the explanatory power of models describing observed performance differences. Responses of local mussel populations differed from those of a common source population suggesting mussel performance partially depended on genetic or persistent phenotypic differences. In light of prior research showing deleterious effects of low pH on larval mussels, our results suggest a life history transition leading to greater resilience in at least some performance metrics to ocean acidification by adult California mussels. Our data also demonstrate "hot" (more extreme) and "cold" (less extreme) spots in both mussel responses and environmental conditions, a pattern that may enable mitigation approaches in response to future changes in climate.


Assuntos
Carbonatos/metabolismo , Mudança Climática , Mytilus/crescimento & desenvolvimento , Oceanos e Mares , Água do Mar/química , Adaptação Fisiológica , Exoesqueleto/química , Animais , Oceano Atlântico , Carbonato de Cálcio/análise , Ecossistema , Concentração de Íons de Hidrogênio , Mytilus/metabolismo , Nutrientes , Tamanho do Órgão , Fitoplâncton , Temperatura , Ondas de Maré
20.
Parasitol Res ; 119(10): 3233-3241, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32656658

RESUMO

Anisakid nematode larvae occur frequently in the liver of Atlantic cod, but merely few infection data from cod in waters around Greenland exist. The present study reports the occurrence of third-stage anisakid larvae in the livers of 200 Atlantic cod caught on fishing grounds along the West coast of Greenland (fjord systems of Maniitsoq) in May, June, August and September 2017. Classical and molecular helminthological techniques were used to identify the nematodes. A total of 200 cod livers were examined, and 194 were infected with third-stage nematode larvae (overall prevalence of infection 97%) with a mean intensity of 10.3 (range between 1 and 44 parasites per fish). Prevalences recorded were 96% for Anisakis simplex (s.l.), 55% for Pseudoterranova decipiens (s.l.) and 8% for Contracaecum osculatum (s.l.). Sequencing the mtDNA cox2 from 8 out of 23 these latter larvae conferred these to C. osculatum sp. B. A clear seasonal variation was observed, with a rise in A. simplex (s.l.) and P. decipiens (s.l.) occurrence in June and August and a decline in September. The study may serve as a baseline for future investigations using the three anisakids as biological indicators in Greenland waters.


Assuntos
Anisaquíase/epidemiologia , Anisakis/isolamento & purificação , Doenças dos Peixes/parasitologia , Gadus morhua/parasitologia , Animais , Anisakis/classificação , Anisakis/genética , Oceano Atlântico/epidemiologia , Ciclo-Oxigenase 2/genética , DNA Mitocondrial/genética , Groenlândia/epidemiologia , Larva , Fígado/parasitologia
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