Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 12.203
Filtrar
1.
Water Res ; 171: 115434, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31927092

RESUMO

Perfluorooctanesulfonate (PFOS) and perfluorooctanoate (PFOA) acids are ubiquitous in the oceans, including remote regions, and are toxic to fish and mammals. The impact to the lowest trophic levels of the food web, however, remains unknown. We challenged natural bacterial communities inhabiting Antarctic coastal waters (Deception Island) with PFOS and PFOA concentrations ranging from 2 ng/L to 600 ng/L that selected for tolerant taxa. After 48 h, concentrations of PFOS decreased by more than 50% and sulfur metabolism-related transcripts were significantly enriched in the treatments suggesting desulfurization of PFOS. Conversely, no significant differences were found between initial and final PFOA concentrations. Gammaproteobacteria and Roseobacter, two abundant groups of marine bacteria, increased their relative activity after 24 h of incubation, whereas Flavobacteriia became the main contributor in the treatments after 6 days. Community activities (extracellular enzyme activity and absolute number of transcripts) were higher in the treatments than in the controls, while bacterial abundances were lower in the treatments, suggesting a selection of PFOS and PFOA tolerant community in the exposed treatments. Our results show a direct effect of PFOS and PFOA exposure on the composition and functionality of natural Antarctic marine microbial communities. While no evidence of defluorination of PFOS or PFOA was detected, probable desulfurization of PFOS depicts a direct link with the sulfur biogeochemistry of the ocean.


Assuntos
Ácidos Alcanossulfônicos , Fluorcarbonetos , Animais , Regiões Antárticas , Caprilatos , Oceanos e Mares
2.
Ecol Lett ; 23(3): 457-466, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31925914

RESUMO

Rising sea surface temperatures are expected to lead to the loss of phytoplankton biodiversity. However, we currently understand very little about the interactions between warming, loss of phytoplankton diversity and its impact on the oceans' primary production. We experimentally manipulated the species richness of marine phytoplankton communities under a range of warming scenarios, and found that ecosystem production declined more abruptly with species loss in communities exposed to higher temperatures. Species contributing positively to ecosystem production in the warmed treatments were those that had the highest optimal temperatures for photosynthesis, implying that the synergistic impacts of warming and biodiversity loss on ecosystem functioning were mediated by thermal trait variability. As species were lost from the communities, the probability of taxa remaining that could tolerate warming diminished, resulting in abrupt declines in ecosystem production. Our results highlight the potential for synergistic effects of warming and biodiversity loss on marine primary production.


Assuntos
Ecossistema , Fitoplâncton , Biodiversidade , Biomassa , Oceanos e Mares
3.
Water Res ; 169: 115225, 2020 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-31677434

RESUMO

Human-induced catchment changes have affected the sedimentary processes in marginal seas, which will impact the transport and burial processes of materials and inevitably impact marine biogeochemical cycles. Organochlorine pesticides (OCPs) and sediment characteristics in surface sediments from the East China Sea (ECS) at two time points (2006 and 2018) were compared to understand the response of OCPs to human-induced catchment changes. A significant coarsening trend occurred after the impoundment of the Three Gorges Dam (TGD), with the mean grain size increasing from 6.4 ±â€¯1.2 Φ to 4.4 ±â€¯2.1 Φ, suggesting that the sedimentary environment in the ECS changed drastically. OCP concentrations in the ECS evidently decreased after the impoundment of the TGD, with mean values decreasing from 2.55 ±â€¯1.51 ng g-1 to 1.08 ±â€¯0.84 ng g-1. The deposition flux of OCP also decreased from 2.65 ±â€¯1.67 ng cm-2 yr-1 to 0.89 ±â€¯0.60 ng cm-2 yr-1. The reduction in the riverine input might be the reason that caused variations in the OCP concentration and deposition flux. In addition, sediment coarsening is likely to be the another primary factor influencing the differences in the distribution and deposition flux of the OCPs in the ECS. Therefore, the distribution and burial of OCPs in the ECS have been changed drastically, which may broadly impact the marine environment and biogeochemical cycles.


Assuntos
Hidrocarbonetos Clorados , Praguicidas , Poluentes Químicos da Água , China , Monitoramento Ambiental , Sedimentos Geológicos , Humanos , Oceanos e Mares
4.
Glob Chang Biol ; 26(1): 31-53, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31696576

RESUMO

Hard, or stony, corals make rocks that can, on geological time scales, lead to the formation of massive reefs in shallow tropical and subtropical seas. In both historical and contemporary oceans, reef-building corals retain information about the marine environment in their skeletons, which is an organic-inorganic composite material. The elemental and isotopic composition of their skeletons is frequently used to reconstruct the environmental history of Earth's oceans over time, including temperature, pH, and salinity. Interpretation of this information requires knowledge of how the organisms formed their skeletons. The basic mechanism of formation of calcium carbonate skeleton in stony corals has been studied for decades. While some researchers consider coral skeletons as mainly passive recorders of ocean conditions, it has become increasingly clear that biological processes play key roles in the biomineralization mechanism. Understanding the role of the animal in living stony coral biomineralization and how it evolved has profound implications for interpreting environmental signatures in fossil corals to understand past ocean conditions. Here we review historical hypotheses and discuss the present understanding of how corals evolved and how their skeletons changed over geological time. We specifically explain how biological processes, particularly those occurring at the subcellular level, critically control the formation of calcium carbonate structures. We examine the different models that address the current debate including the tissue-skeleton interface, skeletal organic matrix, and biomineralization pathways. Finally, we consider how understanding the biological control of coral biomineralization is critical to informing future models of coral vulnerability to inevitable global change, particularly increasing ocean acidification.


Assuntos
Antozoários , Animais , Calcificação Fisiológica , Carbonato de Cálcio , Recifes de Corais , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar
5.
Glob Chang Biol ; 26(1): 54-67, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31743515

RESUMO

The environmental conditions in the ocean have long been considered relatively more stable through time compared to the conditions on land. Advances in sensing technologies, however, are increasingly revealing substantial fluctuations in abiotic factors over ecologically and evolutionarily relevant timescales in the ocean, leading to a growing recognition of the dynamism of the marine environment as well as new questions about how this dynamism may influence species' vulnerability to global environmental change. In some instances, the diurnal or seasonal variability in major environmental change drivers, such as temperature, pH and seawater carbonate chemistry, and dissolved oxygen, can exceed the changes expected with continued anthropogenic global change. While ocean global change biologists have begun to experimentally test how variability in environmental conditions mediates species' responses to changes in the mean, the extensive literature on species' adaptations to temporal variability in their environment and the implications of this variability for their evolutionary responses has not been well integrated into the field. Here, we review the physiological mechanisms underlying species' responses to changes in temperature, pCO2 /pH (and other carbonate parameters), and dissolved oxygen, and discuss what is known about behavioral, plastic, and evolutionary strategies for dealing with variable environments. In addition, we discuss how exposure to variability may influence species' responses to changes in the mean conditions and highlight key research needs for ocean global change biology.


Assuntos
Ecologia , Ecossistema , Carbonatos , Mudança Climática , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar
6.
Ecol Lett ; 23(2): 305-315, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31762170

RESUMO

Geographic isolation substantially contributes to species endemism on oceanic islands when speciation involves the colonisation of a new island. However, less is understood about the drivers of speciation within islands. What is lacking is a general understanding of the geographic scale of gene flow limitation within islands, and thus the spatial scale and drivers of geographical speciation within insular contexts. Using a community of beetle species, we show that when dispersal ability and climate tolerance are restricted, microclimatic variation over distances of only a few kilometres can maintain strong geographic isolation extending back several millions of years. Further to this, we demonstrate congruent diversification with gene flow across species, mediated by Quaternary climate oscillations that have facilitated a dynamic of isolation and secondary contact. The unprecedented scale of parallel species responses to a common environmental driver for evolutionary change has profound consequences for understanding past and future species responses to climate variation.


Assuntos
Evolução Biológica , Clima , Fluxo Gênico , Especiação Genética , Geografia , Ilhas , Oceanos e Mares , Filogenia
7.
Ambio ; 49(2): 460-474, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31278623

RESUMO

To tackle the symptoms of eutrophication in the open Baltic Sea and Finnish coastal waters, Finland has agreed to reduce both total nitrogen (TN) and total phosphorus (TP) inputs. Due to large investments in treatment of municipal and industrial wastewaters, TP loads started to decrease already in the mid-1970s and the respective TN loads in the mid-1990s. During the last two decades, much effort has been spent in decreasing the load originating from diffuse sources. Trend analyses in 1995-2016 showed that, despite various mitigation measures, riverine nutrient export has not substantially decreased, and especially the export from rivers draining agricultural lands remains high. In some areas TN concentrations and export were increasing and we found evidence that it was linked to ditching of peatlands. Several factors connected to climate/weather (e.g. temperature and precipitation) have counteracted the mitigation measures, and therefore Finland will not achieve the nutrient reduction targets by 2021.


Assuntos
Rios , Poluentes Químicos da Água , Países Bálticos , Monitoramento Ambiental , Eutrofização , Finlândia , Nitrogênio , Nutrientes , Oceanos e Mares , Fósforo , Água
8.
Water Res ; 168: 115140, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31604177

RESUMO

The mitigation of microplastic pollution in the environment calls for a better understanding of the sources and transportation, especially from land sources to the open ocean. We conducted a large-scale investigation of microplastic pollution across the Greater Melbourne Area and the Western Port area, Australia, spanning gradients of land-use from un-developed catchments in conservation areas to more heavily-developed areas. Microplastics were detected in 94% of water samples and 96% of sediment samples, with abundances ranging from 0.06 to 2.5 items/L in water and 0.9 to 298.1 items/kg in sediment. The variation of microplastic abundance in sediments was closely related to that of the overlying waters. Fiber was the most abundant (89.1% and 68.6% of microplastics in water and sediment respectively), and polyester was the dominant polymer in water and sediment. The size of more than 40% of all total microplastics observed was less than 1 mm. Both light and dense polymers of different shapes were more abundant in sediments than those in water, indicating that there is microplastic accumulation in sediments. The abundance of microplastics was higher near coastal cities than at less densely-populated inland areas. A spatial analysis of the data suggests that the abundance of microplastics increases downstream in rivers and accumulates in estuaries and the lentic reaches of these rivers. Correlation and redundancy analysis were used to explore the associations between microplastic pollution and different land-use types. More microplastics and polymer types were found at areas with large amounts of commercial, industrial and transport activities. Microplastic abundances were also correlated with mean particle size. Microplastic hotspots within a coastal metropolis might be caused by a combination of natural accumulation via hydrological dynamics and contribution from increasing anthropogenic influences. Our results strongly suggest that coastal metropolis superimposed on increasing microplastic levels in waterbodies from inland areas to the estuaries and open oceans.


Assuntos
Plásticos , Poluentes Químicos da Água , Austrália , Cidades , Monitoramento Ambiental , Sedimentos Geológicos , Oceanos e Mares
9.
Water Res ; 168: 115121, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31605833

RESUMO

Plastic debris and marine microplastics are being discharged into the ocean at an alarming scale and have been observed throughout the marine environment. Here we report microplastic in sediments of the Challenger Deep, the deepest known region on the planet, abyssal plains and hadal trenches located in the Pacific Ocean (4900 m-10,890 m). Microplastic abundance reached 71.1 items per kg dry weight sediment. That high concentrations are found at such remote depths, knowing the very slow sinking speed of microplastics, suggests that supporting mechanisms must be at-play. We discuss cascading processes that transport microplastics on their journey from land and oceanic gyres through intermediate waters to the deepest corners of the ocean. We propose that hadal trenches will be the ultimate sink for a significant proportion of the microplastics disposed in the ocean. The build-up of microplastics in hadal trenches could have large consequences for fragile deep-sea ecosystems.


Assuntos
Plásticos , Poluentes Químicos da Água , Ecossistema , Monitoramento Ambiental , Poluição Ambiental , Oceanos e Mares
10.
Huan Jing Ke Xue ; 41(1): 194-204, 2020 Jan 08.
Artigo em Chinês | MEDLINE | ID: mdl-31854920

RESUMO

At present, research findings on pharmaceuticals and personal care products (PPCPs) in coastal areas are still unclear, and there is a need to develop a method to detect more PPCPs simultaneously in seawater. In this study, nine compounds of non-steroidal anti-inflammatory drugs, antibiotics, lipid regulators. and stimulants were selected as analytes. Solid phase extraction (SPE) was used to extract the compounds, which were then analyzed by high-performance liquid chromatography coupled to mass spectrometry (HPLC-MS). The optimum experimental conditions, such as the filler, eluent, pH, flow rate, and the reduction of matrix effect were optimized during the SPE. The results showed that the best extraction column was CNW HLB, the best eluent was methanol:acetonitrile (1:1, volume ratio), the best eluent volume was 6 mL, the best pH was 7, the best flow rate was 5 mL·min-1, the amount of EDTA-Na2 added was 1 g, and the best concentration multiple was 500. The linear regression equations of all PPCPs had good linearity. Correlation coefficients were>0.999, recovery rates were between 82%-106%, relative standard deviations were between 1.6%-14%, and detection limits were between 0.01-2 ng·L-1, thus satisfying the requirement of trace analysis in seawater. Distribution characteristics and sources of PPCPs were studied in the Yellow Sea and the East China Sea during summer 2018. All nine PPCPs were detected and the main pollutants were NAP, IBU, GEM, CAF, and ASA. High concentrations of PPCPs were generally detected in the nearshore area and displayed conspicuous decreasing tendencies from the inshore towards the offshore. The concentrations of PPCPs in the Yellow Sea were higher than of those in the East China Sea, and this was related to there being more sources of pollutions and poor water exchange capacity in the Yellow Sea. Principal component analysis showed that the main source of PPCPs was terrestrial input. The environmental risk assessment of PPCPs indicated that risk quotients (RQs) of IBU and NAP (0.1-1) posed a medium risk to the aquatic environment, while others posed low risk to organisms.


Assuntos
Cosméticos/análise , Monitoramento Ambiental , Preparações Farmacêuticas/análise , Poluentes Químicos da Água/análise , China , Cromatografia Líquida de Alta Pressão , Espectrometria de Massas , Oceanos e Mares , Medição de Risco , Extração em Fase Sólida
11.
Sci Total Environ ; 701: 134794, 2020 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-31715479

RESUMO

Multiple lines of evidence, ranging from time series field observations to climate change stimulation experiments demonstrate the negative effects of global warming and ocean acidification (OA) on bivalve molluscs. The impact of global warming on bivalve aquaculture has recently been reviewed. However, the impact of OA on bivalve aquaculture has received relatively less attention. Although there are many reports on the effects of OA on bivalves, this information is poorly organized and the connection between OA and bivalve aquaculture is unclear. Therefore, understanding the potential impact of acidification on ecosystems and bivalve aquaculture is of prime importance. Here, we provide a comprehensive scientific review of the impact of OA on bivalves and propose mitigation measures for future bivalve farming. This information will help to establish aquaculture and fisheries management plans to be implemented in commercial fisheries and nature conservation. In general, scientific evidence suggests that OA threatens bivalves by diminishing the availability of carbonate minerals, which may adversely affect the development of early life stages, calcification, growth, byssus attachment and survival of bivalves. The Integrated multi-trophic aquaculture (IMTA) approach is a useful method in slowing the effects of climate change, thereby providing longer adaptation period for bivalves to changing ocean conditions. However, for certain regions that experience intense OA effects or for certain bivalve species that have much longer generational time, IMTA alone may not be sufficient to protect bivalves from the adverse effects of climate change. Therefore, it is highly recommended to combine IMTA and genetic breeding methods to facilitate transgenerational acclimation or evolution processes to enhance the climate resilience of bivalves.


Assuntos
Aquicultura/métodos , Bivalves , Animais , Aquecimento Global , Concentração de Íons de Hidrogênio , Oceanos e Mares , Água do Mar/química
12.
Chemosphere ; 238: 124560, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31437632

RESUMO

Plastics are the most abundant marine debris globally dispersed in the oceans and its production is rising with documented negative impacts in marine ecosystems. However, the chemical-physical and biological interactions occurring between plastic and planktonic communities of different types of microorganisms are poorly understood. In these respects, it is of paramount importance to understand, on a molecular level on the surface, what happens to plastic fragments when dispersed in the ocean and directly interacting with phytoplankton assemblages. This study presents a computer-aided analysis of electron paramagnetic resonance (EPR) spectra of selected spin probes able to enter the phyoplanktonic cell interface and interact with the plastic surface. Two different marine phytoplankton species were analyzed, such as the diatom Skeletonema marinoi and dinoflagellate Lingulodinium polyedrum, in absence and presence of polyethylene terephthalate (PET) fragments in synthetic seawater (ASPM), in order to in-situ characterize the interactions occurring between the microalgal cells and plastic surfaces. The analysis was performed at increasing incubation times. The cellular growth and adhesion rates of microalgae in batch culture medium and on the plastic fragments were also evaluated. The data agreed with the EPR results, which showed a significant difference in terms of surface properties between the diatom and dinoflagellate species. Low-polar interactions of lipid aggregates with the plastic surface sites were mainly responsible for the cell-plastic adhesion by S. marinoi, which is exponentially growing on the plastic surface over the incubation time.


Assuntos
Diatomáceas/metabolismo , Dinoflagelados/metabolismo , Microalgas/crescimento & desenvolvimento , Fitoplâncton/metabolismo , Plásticos/metabolismo , Polietilenotereftalatos/metabolismo , Ecossistema , Espectroscopia de Ressonância de Spin Eletrônica , Microalgas/metabolismo , Oceanos e Mares , Água do Mar/química , Resíduos/análise
13.
Chemosphere ; 240: 124870, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31550586

RESUMO

Compounds such as estradiol and ethinylestradiol belong to contaminants of emerging concern, as they can disrupt the endocrine system of an organism with a hormonal system. The determination of such compounds is still challenging due to required low detection and quantification limits. Bioassays have proved to be sensitive tools for investigating the full potential of all compounds that can elicit an estrogenic response. In this study, surface water samples from different sampling sites and seasons in the Baltic Sea were analyzed for estrogenic activity with the Arxula adeninivorans yeast estrogen screen. Observed estradiol equivalent concentrations were in the range of

Assuntos
Monitoramento Ambiental/métodos , Estrogênios/química , Poluentes Químicos da Água/química , Estrogênios/análise , Oceanos e Mares , Poluentes Químicos da Água/análise
14.
Chemosphere ; 239: 124785, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31726533

RESUMO

The concentrations of total and proportions of organic mercury were measured in tissues of 355 individuals of 8 species of Southern Ocean squid (Alluroteuthis antarcticus, Bathyteuthis abyssicola, Filippovia knipovitchi, Galiteuthis glacialis, Gonatus antarcticus, Kondakovia longimana, Psychroteuthis glacialis and Slosarczykovia circumantarctica). Squid were caught around South Georgia (Scotia Sea) during 5 cruises, between the austral summers of 2006/07 to 2016/17 to evaluate temporal changes in bioaccumulation and tissue partitioning. Total mercury concentrations varied between 4 ng g-1 and 804 ng g-1 among all tissues. Net accumulation of mercury in muscle with size was observed in A. antarcticus, B. abyssicola and P. glacialis, but no relationship was found for S. circumantarctica and lower concentrations were observed in larger individuals of G. glacialis. Muscle tissues had the highest mercury concentrations in the majority of species, except for F. knipovitchi for which the digestive gland contained highest concentrations. In terms of the percentage of organic mercury in the tissues, muscle always contained the highest values (67%-97%), followed by the digestive gland (22%-38%). Lowest organic mercury percentages were found consistently in the gills (9%-19%), suggesting only low levels of incorporation through the dissolved pathway and/or a limited redistribution of dietary organic mercury towards this tissue. Overall, results are indicative of a decreasing trend of mercury concentrations in the majority of analysed species over the last decade. As cephalopods are an important Southern Ocean trophic link between primary consumers and top predators, these changes suggest decreasing mercury levels in lower trophic levels and an alleviation of the mercury burden on higher predators that consume squid.


Assuntos
Decapodiformes/química , Monitoramento Ambiental/métodos , Mercúrio/análise , Músculos/química , Poluentes Químicos da Água/análise , Animais , Cadeia Alimentar , Ilhas , Oceanos e Mares , Alimentos Marinhos/análise
15.
Talanta ; 206: 120213, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31514887

RESUMO

Phthalate esters (PAEs) are an important kind of environmental endocrine disrupting chemicals, and have attracted great attention in environmental field. Present study described a new method for rapid and sensitive determination of PAEs including dibenzyl phthalate (DPhP), dibutyl phthalate (DnPP), and dicyclohexyl phthalate (DCHP) from aqueous matrices based on magnetic solid-phase extraction. Polyamidoamine (PAMAM) dendrimers-grafted magnetic-nanoparticles were synthesized and characterized, and the expected integration of more multifunctional sites of PAMAM dendrimers and rapid separation property was utilized for method development. To achieve the best extraction efficiency, several important parameters were optimized including the dosage of the adsorbent, sample pH, kind and volume of eluent, extraction time, desorption time, ionic strength. Under the optimal conditions, three phthalate esters were well enriched and simultaneously determined by high performance liquid chromatography with variable wavelength detector (VWD). Excellent linearities were observed in the range of 0.1-600 µg L-1 for DPhP and DnPP and 0.5-600 µg L-1 for DCHP, and all correlation coefficients (R2) were larger than 0.997. The limits of detection (LODs, S/N = 3) were ranged from 0.025 to 0.16 µg L-1. The spiked recoveries of PAEs in real water samples were in the range of 93.5-101.8% with satisfied relative standard deviations (RSDs) ranging from 0.9 to 4.1%. The prepared magnetic materials have shown good adsorption capability for PAEs and the developed method earned merits such as high sensitivity, simplicity, rapidness and environmental friendliness, which can be used as a robust alternative tool for monitoring PAEs in water samples.


Assuntos
Dendrímeros/química , Ésteres/análise , Nanopartículas de Magnetita/química , Ácidos Ftálicos/análise , Poluentes Químicos da Água/análise , Cromatografia Líquida de Alta Pressão/métodos , Dibutilftalato/análise , Lagos/análise , Limite de Detecção , Oceanos e Mares , Extração em Fase Sólida/métodos
16.
Science ; 366(6471): 1316-1317, 2019 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-31831660
17.
Science ; 366(6469): 1076-1077, 2019 11 29.
Artigo em Inglês | MEDLINE | ID: mdl-31780545
18.
Environ Sci Technol ; 53(22): 13064-13070, 2019 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-31670933

RESUMO

Methanesulfonic acid (MSA), derived from the oxidation of dimethylsulfide (DMS), has a significant impact on biogenic sulfur cycle and climate. Gaseous MSA (MSAg) has been often ignored in previous studies due to its quick conversion to particulate MSA (MSAp) and low concentrations. MSAg, MSAp, and nss-SO42- were observed simultaneously for the first time with high-time-resolution (1 h) in the Southern Ocean (SO). The mean MSAg level reached up to 3.3 ± 1.6 pptv, ranging from ∼24.5 pptv in the SO, contributing to 31% ± 3% to the total MSA (MSAT). A reduction of the MSA to nss-SO42- ratios by about 30% was obtained when MSAg was not accounted for in the calculation, indicating that MSAg was very important in the assessment of the biogenic sulfur contributions in the atmosphere. Mass ratios of MSA to nss-SO42- increased first and then decreased with the temperature from -10 to 5 °C, with a maximum value at the temperature of -3 °C. Positive correlations between MSAg to MSAT ratios and temperature were presented, when the temperature was higher than 5 °C. This study highlights the importance of MSAg for understanding the atmospheric DMS oxidation mechanism and extends the knowledge of MSA formation in the marine atmosphere.


Assuntos
Atmosfera , Gases , Aerossóis , Mesilatos , Oceanos e Mares
19.
Zootaxa ; 4694(1): zootaxa.4694.1.1, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31719372

RESUMO

Trindade and Martin Vaz (TMV) is a highly isolated, oceanic volcanic archipelago located some 1200 km off the Brazilian coast and about 4200 km away from the nearest African coast. For almost 100 years Calcinus tibicen (Herbst, 1791) was the only hermit crab species known from TMV. From 2012 to 2018, 263 daytime SCUBA diving and intertidal samplings conducted at TMV yielded 1075 paguroid specimens in 10 species, three of which are established herein as new species: Iridopagurus martinvaz sp. nov., Nematopagurus micheleae sp. nov., and Pagurus carmineus sp. nov. Iridopagurus margaritensis García-Gómez, 1983, and Phimochirus leurocarpus McLaughlin, 1981, both only known from the northern hemisphere, are recorded for the first time from the southwestern Atlantic. Opportunity was taken herein to include hitherto unreported or little known specimens from along the Vitória-Trindade Seamount Chain, namely, Dardanus venosus H. Milne Edwards, 1848, Nematopaguroides pusillus Forest de Saint Laurent, 1968, Pagurus provenzanoi Forest de Saint Laurent, 1968, and Phimochirus holthuisi (Provenzano, 1961). The lectotype of Pagurus venosus H. Milne Edwards, 1848 is designated as the neotype for the obscure Pagurus arrosor divergens Moreira, 1905, which thus becomes an objective junior synonym of the former. A list of all paguroid species known from the tropical southern-central Atlantic oceanic archipelagoes and islands (Ascension, Cape Verde, Fernando de Noronha, Gulf of Guinea, Rocas Atoll, Saint Helena, Trindade and Martin Vaz) with their gross distribution in the Atlantic Ocean is provided. Investigation on the existence of patterns of geographic distribution for the paguroid fauna of the tropical southern-central Atlantic oceanic islands showed that 70% percent of the paguroids from TMV are western Atlantic in origin and 30% endemic. No amphi-Atlantic paguroid species are known from TMV. Conversely, the affinity of Ascension's (33%) and Saint Helena's (50%) paguroids is with the eastern Atlantic; no western Atlantic paguroids have been reported from these two islands so far. Exploration on the existence of trends of correlation between islands area and species richness through the Spearman's coefficient of correlation showed that the patterns in the number of paguroid species cannot be explained by variation in island area alone (rs = 0.4728; p = 0.28571).


Assuntos
Anomuros , Animais , Ilhas Atlânticas , Oceano Atlântico , Brasil , Cabo Verde , Ilhas , Oceanos e Mares
20.
Zootaxa ; 4692(1): zootaxa.4692.1.1, 2019 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-31719374

RESUMO

Black corals (Cnidaria: Hexacorallia: Antipatharia) occur in all oceans of the globe, especially at depths greater than 50 m. However, their richness is underestimated due to the scarcity of studies on this group, especially in deep waters. The south Atlantic is one of the most depauperate regions in terms of our knowledge of antipatharians. Herein, we report 34 antipatharian species for the Southwestern Atlantic. Additionally, based on the examination of museum specimens, three species are new records in the Atlantic (Parantipathes laricides; Stichopathes paucispina and S. spiessi); and 17 had their distribution expanded, representing six families (Antipathidae, Cladopathidae, Leiopathidae, Myriopathidae, Schizopathidae and Stylopathidae). Additionally, the richness, distribution and associations of antipatharians are briefly discussed. An artificial key to South Atlantic antipatharians is included.


Assuntos
Antozoários , Animais , Oceano Atlântico , Oceanos e Mares
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA