Sediment depth and habitat as predictors of the diversity and composition of sediment bacterial communities in an inter‐tidal estuarine environment          下载免费PDF全文

Daniel F. R. Cleary  Francisco J. R. C. Coelho  Vanessa Oliveira  Newton C. M. Gomes  Ana R. M. Polónia 《Marine Ecology》2017,38(2)

Saltmarshes, seagrass meadows and mudflats are key habitats in estuarine ecosystems. Despite being involved in key ecological processes, the influence of different estuarine habitats on sediment bacterial communities remains understudied. Few studies have analysed and compared the bacterial communities of more than one estuarine habitat at different depths. Here, we investigated to what extent different habitats (mudflats; mono‐specific plots of seagrass [Zostera noltei] and two saltmarsh plants [Juncus maritimus and Spartina maritima]) and sampling depth (0, 5, 10 cm) influence variation in sediment bacterial composition. Our results showed significant differences in the abundance of selected higher taxa amongst habitats and depths. Surface sediment was characterized by bacteria assigned to the Acidimicrobiia, Flavobacteriia, Thiotrichales, Alteromonadales and Rhodobacterales, whereas in deeper sediment Deltaproteobacteria and Anaerolineae were dominant. Juncus sediment, in turn, presented the most distinct bacterial community, with Myxococcales abundant in this habitat. Sampling depth and habitat proved significant predictors of variation in sediment bacterial composition. The compositional dissimilarities amongst habitats and depths suggest functional divergence and complementarity, thus enhancing ecosystem functioning and health. Given the compositionally distinct communities found in different habitats and depths, our study corroborates the importance of conserving a diverse array of estuarine habitats.  相似文献   

Shell use by sympatric hermit crab species in a seasonally open coastal lagoon in Northeastern Brazil          下载免费PDF全文

Valéria F. Vale  Sávio A. S. N. Moraes  Vanessa L. G. Brito  Carlos E. R. D. Alencar  Fúlvio A. M. Freire 《Marine Ecology》2017,38(5)

There are gaps in what is known about the patterns of gastropod shell use by hermit crabs in Brazilian lagoon areas, especially in Northeastern Brazil. However, this is important because the understanding of selection patterns provides information on life history and eco‐evolutionary conceptions of paguroids. The present study investigated the use of gastropod shells occupied by Pagurus criniticornis and Clibanarius sclopetarius in a coastal lagoon seasonally connected to an estuary and to the sea, correlating eco‐evolutionary aspects and hydrodynamic characters. The study was carried out between February 2013 and January 2014. Hermit crabs and their shells were identified and measured (hermit crabs’ cephalothorax shield length and width, major propodus length and height, weight, shell total length and width, shell aperture length and width). Partial least squares regression was used to analyse the morphometric data. Additionally, a multinomial proportions test was performed to infer patterns (inter‐/intra‐specific) of shells’ occupation. Hermit crab species occupied a total of 13 types of shells, predominantly those of Neritina virginea (67.83%). The shell weight was the most important determinant of shell occupancy in the morphometric model (variable importance in projection >1). The proportions of N. virginea shells used were similar in both species of hermit crabs, except between the sexes of P. criniticornis. Presumably, the high utilization rate of N. virginea shells is related to its abundance and dispersal, and to the shells’ suitability for hermit crabs, which is reflected by the morphometric model, as well as by the hydrodynamics of the lagoon‐estuarine environment. The relative occupation of different types of shells for each species of hermit crabs studied appears to be associated with regulation by inter‐/intra‐specific competition, which fosters the co‐occurrence of those populations. These results endorse coastal lagoons as a refuge and recruitment area for aquatic fauna. In addition, it highlights a challenge in the management and conservation of paguroid species whose population dynamics depend on the resources coming from the Gastropoda community.  相似文献   

Sedimentology of Coastal Deposits in the Seychelles Islands—Evidence of the Indian Ocean Tsunami 2004     

Vanessa Nentwig  Heinrich Bahlburg  Devis Monthy 《Pure and Applied Geophysics》2015,172(3-4):641-656

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Spatial assessment of fishing effort around European marine reserves: implications for successful fisheries management   总被引：7，自引：0，他引：7  

Stelzenmüller V  Maynou F  Bernard G  Cadiou G  Camilleri M  Crec'hriou R  Criquet G  Dimech M  Esparza O  Higgins R  Lenfant P  Pérez-Ruzafa A 《Marine pollution bulletin》2008,56(12):2018-2026

We examined the spatial dynamic of artisanal fishing fleets around five European marine protected areas (MPAs) to derive general implications for the evaluation of MPAs as fisheries management tools. The coastal MPAs studied were located off France, Malta and Spain and presented a variety of spatial designs and processes of establishment. We developed a standardized methodology to define factors influencing effort allocation and to produce fishing effort maps by merging GIS with geostatistical modelling techniques. Results revealed that in most cases the factors “distance to the no-take”, “water depth”, and “distance to the port” had a significant influence on effort allocation by the fishing fleets. Overall, we found local concentration of fishing effort around the MPA borders. Thus, neglecting the pattern of fishing effort distribution in evaluating MPA benefits, such as spillover of biomass, could hamper sound interpretation of MPAs as fisheries management tools.  相似文献   

Trace metals and benthic macrofauna distributions in Camamu Bay, Brazil: sediment quality prior oil and gas exploration     

Hatje V  Barros F  Magalhães W  Riatto VB  Amorim FN  Figueiredo MB  Spanó S  Cirano M 《Marine pollution bulletin》2008,56(2):363-370

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The wollongong lead study: an investigation of the blood lead levels of pre‐school children and their relationship to soil lead levels     

A.R.M. Young  E.A. Bryant  H.P.M. Winchester 《The Australian geographer》1992,23(2):121-133

The Wollongong Lead Study was undertaken in 1989–90 by the Pollution Task Force of Healthy Cities Illawarra and the Health Promotion Unit of the Illawarra Area Health Service. It was done in response to community concern in the Port Kembla area about the health effects of known high atmospheric lead levels, which result from the emissions from the Electrolytic Refining & Smelting Pty Ltd (now Southern Copper) smelter. It followed procedures similar to those used in the extensive and long‐term studies of the consequences of emissions from the lead smelter at Port Pirie in South Australia and concentrated on the highest risk group identified by the Port Pirie work, namely very young children (mainly 1–3 years). This paper reports the aspects of the study related to soil‐blood level relationships.

Two areas were compared: a southern area near the smelter; and a northern area near Bellambi which was used as a control because it is not usually affected by air pollution from the industrial zone at Port Kembla. A total of 164 soil samples and 83 blood samples were collected from the southern area, together with 79 soil samples and 30 blood samples from the northern area. Soil lead levels were not high by world standards in either region. The southern area had greater levels than the northern area. While there was no apparent pattern in the northern area, soil lead levels rose significantly towards the smelter at Port Kembla. Blood lead levels were also higher in the southern area. Here they rose from the south towards the industrial area generally, rather than peaking near the smelter. In the northern area there was no pattern apparent. Soil levels were significantly correlated with blood levels (significance level >0.05) and explained 29 per cent of the variation in the blood data. Soil lead levels can be used, therefore, as a general indicator of likely high blood lead levels in young children. Seven children (8%) in the southern area and two children (7%) in the northern area had blood lead levels above the NH&MRC recommended level of concern (25 μg/dL).  相似文献   

Biogeochemical Behavior of Arsenic Species at Paranaguá Estuarine Complex, Southern Brazil     

Vanessa E. dos Anjos  Eunice da C. Machado  Marco T. Grassi 《Aquatic Geochemistry》2012,18(5):407-420

The behavior and dynamics of arsenic at Ilha do Mel, Guaraque?aba, and Paranaguá, located in the Paranaguá Estuarine Complex, Brazil, were investigated in this work. Samples were collected in March, September, and December of 2005. With respect to arsenic behavior, the total concentrations were higher for Paranaguá (22.5?±?2.5?μg?L^?1) on average, followed by the samples of Guaraque?aba (14.4?±?3.2?μg?L^?1) and Ilha do Mel (8.7?±?1.1?μg?L^?1). The concentrations found in this work were consistently greater when compared to other estuaries. The results can be attributed to geological factors. Nevertheless, it was also possible to realize that higher concentrations were found in Paranaguá, the more impacted environment. These results represent a strong indication that human activities in the area contribute to the enrichment of the estuary with this metalloid. Arsenic was mainly present in the dissolved phase, which corresponded to more than 70% of the total concentration. This behavior can represent a greater residence time of this metalloid in the water column. The marine phytoplankton presence was decisive in dictating the distribution of As in the waters of Paranaguá estuary. Organic species, which are considered the less toxic, were found in higher concentrations in the eutrophic areas such as Guaraque?aba and Paranaguá. This was a typical behavior during the summer probably due to higher biological activity.  相似文献   

The influence of environmental characteristics on fish larvae spatial patterns related to a marine protected area: The Medes islands (NW Mediterranean)     

ngel Lpez-Sanz  Vanessa Stelzenmüller  Francesc Maynou  Ana Sabats 《Estuarine, Coastal and Shelf Science》2011,92(4):187

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Double-difference Relocation of the Aftershocks of the Tecom��n, Colima, Mexico Earthquake of 22 January 2003     

Vanessa Andrews  Joann Stock  Carlos Ariel Ram��rez V��zquez  Gabriel Reyes-D��vila 《Pure and Applied Geophysics》2011,168(8-9):1331-1338

On 22 January 2003, the M _w?=?7.6 Tecomán earthquake struck offshore of the state of Colima, Mexico, near the diffuse triple junction between the Cocos, Rivera, and North American plates. Three-hundred and fifty aftershocks of the Tecomán earthquake with magnitudes between 2.6 and 5.8, each recorded by at least 7 stations, are relocated using the double difference method. Initial locations are determined using P and S readings from the Red Sismológica Telemétrica del Estado de Colima (RESCO) and a 1-D velocity model. Because only eight RESCO stations were operating immediately following the Tecomán earthquake, uncertainties in the initial locations and depths are fairly large, with average uncertainties of 8.0?km in depth and 1.4?km in the north?Csouth and east?Cwest directions. Events occurring between 24 January and 31 January were located using not only RESCO phase readings but also additional P and S readings from 11 temporary stations. Average uncertainties decrease to 0.8?km in depth, 0.3?km in the east?Cwest direction, and 0.7?km in the north?Csouth direction for events occurring while the temporary stations were deployed. While some preliminary studies of the early aftershocks suggested that they were dominated by shallow events above the plate interface, our results place the majority of aftershocks along the plate interface, for a slab dipping between approximately 20° and 30°. This is consistent with the slab positions inferred from geodetic studies. We do see some upper plate aftershocks that may correspond to forearc fault zones, and faults inland in the upper plate, particularly among events occurring more than 3?months after the mainshock.  相似文献   

Characterisation and sediment–source linkages of intertidal sediment of the UK’s north Sefton Coast using magnetic and textural properties: findings and limitations     

Vanessa J. C. Holden  Annie T. Worsley  Colin A. Booth  Graham Lymbery 《Ocean Dynamics》2011,61(12):2157-2179

Sediment pathways and links to offshore processes are considered in the textural and magnetic characteristics of sediments of the intertidal flats and salt marshes of the north Sefton Coast, UK. In addition, sediment from a range of intertidal, marine and fluvial locations within the northwest region has similarly been characterised. Subsequently, the characteristics of these regional sediments, using a multivariate statistical approach of R- and Q-mode factor analyses, have been used to investigate the sediment transport pathways of the north Sefton Coast sediment. The benefits of fractionating sediment samples have been observed, and by using combinations of textural and isothermal remanent magnetic measurements, specific environments within the research have been successfully differentiated and characterised. Linkages between potential sediment source areas have also been established on a particle size-related basis.  相似文献