scholarly journals Annual, seasonal and spatial abundance of the seabob shrimp Xiphopenaeus kroyeri (Decapoda, Penaeidae) off the Southeastern coast of Brazil

2014 ◽  
Vol 86 (3) ◽  
pp. 1337-1346 ◽  
Author(s):  
GISELE S. HECKLER ◽  
MATEUS LOPES ◽  
SABRINA M. SIMÕES ◽  
ROBERTO M. SHIMIZU ◽  
ROGERIO C. DA COSTA
Keyword(s):  
Grain Size ◽  
Temporal Distribution ◽  
Fine Sand ◽  
Spatial And Temporal Distribution ◽  
Sediment Grain Size ◽  
Low Salinity ◽  
Sampling Locations ◽  
Xiphopenaeus Kroyeri ◽  
Reproductive Females ◽  
Estuarine Region

We investigated the influence of environmental factors in spatial and temporal distribution of the seabob shrimp Xiphopenaeus kroyeri in Santos Bay and São Vicente Estuary, state of São Paulo, Brazil. Monthly samples were obtained, from May 2008 through April 2010, from four locations in the estuary and four in the bay. No individual was collected in the estuary and this was attributed to the low salinity means recorded in this environment. We collected 109,153 individuals in the bay and there was no difference in abundance between the two years comprised by the study period. The similarity in spatial distribution can be related to sediment grain size that in all sampling locations showed great amount of very fine sand. The largest amount of reproductive females was obtained in early 2010, when temperature was high, and this could have increased the juvenile recruitment in April 2010. According to our results, the distribution of X. kroyeri in the study area is influenced by temperature, which is related to reproduction, and salinity, limiting the entrance of individuals in the estuarine region.

scholarly journals Abundance and spatial-temporal distribution of Macrobrachium surinamicum Holthuis, 1948 (Palaemonidae) in the Amazon estuary, north of Brazil

2016 ◽  
Vol 77 (3) ◽  
pp. 594-601
Author(s):  
D. V. Cavalcante ◽  
B. S. Bentes ◽  
J. M. Martinelli-Lemos
Keyword(s):  
Significant Influence ◽  
Abiotic Factors ◽  
Temporal Distribution ◽  
Artisanal Fisheries ◽  
Spatial And Temporal Distribution ◽  
Low Salinity ◽  
Amazon Estuary ◽  
Disturbed Areas ◽  
Macrobrachium Amazonicum ◽  
The City

Abstract Macrobrachium surinamicum is a small shrimp that inhabits rivers of low salinity. It is mainly caught as bycatch in Amazon shrimp Macrobrachium amazonicum fisheries, which is widely exploited by artisanal fisheries for food and economic needs of the riverside population. This study aimed to characterize the spatial and temporal distribution of the freshwater shrimp M. surinamicum in the Guajará Bay and on Mosqueiro Island, correlating the abundance of this species with abiotic factors (temperature and salinity). Samples were taken from May 2006 to April 2007 in six locations: Mosqueiro Island (Furo das Marinhas and Porto do Pelé); Icoaraci district; Arapiranga Island, edge of the city of Belém; and Combu Island, using traps named 'matapis'. A total of 361 shrimps were caught. The abundance was higher in December and lower in July 2006. The biggest catch occurred on Arapiranga Island and the lowest on Mosqueiro Island. The abundance differed significantly in December 2006 and no variable studied had significant influence on M. surinamicum abundance. In Guajará Bay, particularly the more sheltered places, as Arapiranga and Combu islands, favor the development of M. surinamicum, indicating that this species has preference for less disturbed areas.

scholarly journals Distribution and density of the mollusk Donax striatus (Linnaeus, 1767) in a tropical estuarine region in the brazilian semi-arid

2015 ◽  
Vol 75 (4) ◽  
pp. 914-922 ◽  
Author(s):  
E. L. Medeiros ◽  
G. V. Fernandes ◽  
G. G. Henry-Silva
Keyword(s):  
Intertidal Zone ◽  
Significant Positive Correlation ◽  
River Estuary ◽  
Temporal Distribution ◽  
Average Density ◽  
Spatial And Temporal Distribution ◽  
Tropical Estuarine ◽  
Sampling Points ◽  
Estuarine Region ◽  
Semi Arid

Abstract This study evaluated the spatial and temporal distribution and density of the bivalve Donax striatus, at beaches close to the Apodi/Mossoró River estuary, through, six semiannual sampling campaigns were performed between April/2009 and October/2011. The sampled area was delimited by 20 transects that were laid perpendicular to the beach line and extended over 300 m in the intertidal zone. Seven sampling points were established in each transect, organisms and sediment were collected, and water temperature and salinity were recorded. The highest D. striatus average density (103 individuals.m–2) was observed in April/2009 and the lowest (18 individuals.m–2) in October/2010. The highest D. striatus densities occurred in beaches further from the estuarine region as demonstrated by a significant positive correlation (r2 = 0.67 and p = 0.0007). The D. striatus densities presented significant negative correlations with the percentages of organic matter in the water. This species demonstrated an aggregated distribution in the studied area.

The spatial and temporal distribution of grain-size breaks in turbidites

Sedimentology ◽  
2014 ◽  
Vol 61 (4) ◽  
pp. 1120-1156 ◽  
Author(s):  
Christopher J. Stevenson ◽  
Peter J. Talling ◽  
Douglas G. Masson ◽  
Esther J. Sumner ◽  
Michael Frenz ◽  
...  
Keyword(s):  
Grain Size ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution

scholarly journals Granulometric characterization of sediments transported by surface runoff generated by moving storms

2008 ◽  
Vol 15 (6) ◽  
pp. 999-1011 ◽  
Author(s):  
J. L. M. P. de Lima ◽  
C. S. Souza ◽  
V. P. Singh
Keyword(s):  
Grain Size ◽  
Surface Runoff ◽  
Laboratory Experiments ◽  
Overland Flow ◽  
Temporal Distribution ◽  
Surface Flow ◽  
Constant Speed ◽  
Stream Power ◽  
Sediment Grain Size ◽  
Rain Simulator

Abstract. Due to the combined effect of wind and rain, the importance of storm movement to surface flow has long been recognized, at scales ranging from headwater scales to large basins. This study presents the results of laboratory experiments designed to investigate the influence of moving rainfall storms on the dynamics of sediment transport by surface runoff. Experiments were carried out, using a rain simulator and a soil flume. The movement of rainfall was generated by moving the rain simulator at a constant speed in the upstream and downstream directions along the flume. The main objective of the study was to characterize, in laboratory conditions, the distribution of sediment grain-size transported by rainfall-induced overland flow and its temporal evolution. Grain-size distribution of the eroded material is governed by the capacity of flow that transports sediments. Granulometric curves were constructed using conventional hand sieving and a laser diffraction particle size analyser (material below 0.250 mm) for overland flow and sediment deliveries collected at the flume outlet. Surface slope was set at 2%, 7% and 14%. Rainstorms were moved with a constant speed, upslope and downslope, along the flume or were kept static. The results of laboratory experiments show that storm movement, affecting the spatial and temporal distribution of rainfall, has a marked influence on the grain-size characteristics of sediments transported by overland flow. The downstream-moving rainfall storms have higher stream power than do other storm types.

scholarly journals Universal relation with regime transition for sediment transport in fine-grained rivers

2019 ◽  
Vol 117 (1) ◽  
pp. 171-176 ◽  
Author(s):  
Hongbo Ma ◽  
Jeffrey A. Nittrouer ◽  
Baosheng Wu ◽  
Michael P. Lamb ◽  
Yuanfeng Zhang ◽  
...  
Keyword(s):  
Grain Size ◽  
Sediment Load ◽  
Yellow River ◽  
Fine Sand ◽  
Sediment Flux ◽  
Universal Relation ◽  
Sediment Grain Size ◽  
Fine Grained ◽  
Predictive Algorithm ◽  
Sediment Size

Fine-grained sediment (grain size under 2,000 μm) builds floodplains and deltas, and shapes the coastlines where much of humanity lives. However, a universal, physically based predictor of sediment flux for fine-grained rivers remains to be developed. Herein, a comprehensive sediment load database for fine-grained channels, ranging from small experimental flumes to megarivers, is used to find a predictive algorithm. Two distinct transport regimes emerge, separated by a discontinuous transition for median bed grain size within the very fine sand range (81 to 154 μm), whereby sediment flux decreases by up to 100-fold for coarser sand-bedded rivers compared to river with silt and very fine sand beds. Evidence suggests that the discontinuous change in sediment load originates from a transition of transport mode between mixed suspended bed load transport and suspension-dominated transport. Events that alter bed sediment size near the transition may significantly affect fluviocoastal morphology by drastically changing sediment flux, as shown by data from the Yellow River, China, which, over time, transitioned back and forth 3 times between states of high and low transport efficiency in response to anthropic activities.

scholarly journals Spatial and temporal distribution of bats (Chiroptera) in bright summer nights

2016 ◽  
Vol 66 (1) ◽  
pp. 65-80 ◽  
Author(s):  
Tore Christian Michaelsen
Keyword(s):  
Spatial Distribution ◽  
Distribution Pattern ◽  
Temporal Distribution ◽  
Spatial Distribution Pattern ◽  
Spatial And Temporal Distribution ◽  
Pronounced Increase ◽  
Low Salinity ◽  
Non Linear ◽  
Over Time

Most bat species show plasticity in their choice of habitat and landscape. This study focuses on the distribution and activity of bats along the hillsides and onto the shores of a low salinity marine Norwegian fiord at 62°N. Ultrasound was recorded using D500 detectors in June and July at 42 different sites from the shoreline and up the hillsides to around 200 m. Detectors were placed in well-preserved woodlands. OnlyPipistrellussp., northern batsEptesicus nilssoniiand bats of theMyotisgenus were common. There was a clear non-linear spatial distribution pattern along these slopes, with a pronounced increase in the number of recorded bats at short distances from the shore. On all six nights, the detector closest to the shore had the highest number of recorded bats. A pattern was also seen in bat distribution over time.Pipistrellussp., northern bats andMyotisspecies all had a peak near the shore during the darkest part of the night, which is around 01.35 h in mid-summer at this latitude. At greater distances,Pipistrellussp. and northern bats had a peak around 40 minutes to one hour before the darkest part of the night, respectively. Here,Myotisspp. peaked about an hour after 01.35.

scholarly journals Multifoci and multiserotypes circulation of dengue virus in Senegal between 2017 and 2018

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Idrissa Dieng ◽  
Marie Henriette Dior Ndione ◽  
Cheikh Fall ◽  
Moussa Moïse Diagne ◽  
Mamadou Diop ◽  
...  
Keyword(s):  
Dengue Virus ◽  
Dengue Infection ◽  
Temporal Distribution ◽  
Spatial And Temporal Distribution ◽  
Genotype Iii ◽  
Life Threatening Illness ◽  
Sampling Locations ◽  
Life Threatening ◽  
Dengue Virus Serotypes ◽  
Genotype V

Abstract Background Dengue fever is a mosquito born disease associated with self-limited to life threatening illness. First detected in Senegal in the nineteenth century, and despite its growing incidence this last decade, significant knowledge gaps exist in our knowledge of genetic diversity of circulating strains. This study highlights the circulating serotypes and genotypes between January 2017 and December 2018 and their spatial and temporal distribution throughout all regions of Senegal. Methods We used 56 dengue virus (DENV) strains for the analysis collected from 11 sampling areas: 39 from all regions of Senegal, and 17 isolates from Thiès, a particular area of the country. Two real time RT-qPCR systems were used to confirm dengue infection and corresponding serotypes. For molecular characterization, CprM gene was sequenced and submitted to phylogenetic analysis for serotypes and genotypes assignment. Results Three dengue virus serotypes (DENV-1–3) were detected by all used methods. DENV-3 was detected in 50% (28/56) of the isolates, followed by DENV-1 and DENV-2, each representing 25% (14/56) of the isolates. DENV-3 belongs to genotype III, DENV-1 to genotype V and DENV-2 to Cosmopolitan genotype. Serotype 3 was detected in 7 sampling locations and a co-circulation of different serotypes was observed in Thiès, Fatick and Richard-toll. Conclusions These results emphasize the need of continuous DENV surveillance in Senegal to detect DENV cases, to define circulating serotypes/genotypes and to prevent the spread and the occurrence of severe cases.

scholarly journals Long-term patterns of spatial and temporal distribution in the seabob shrimp Xiphopenaeus kroyeri (Decapoda: Penaeidae) population in southeastern Brazil

2014 ◽  
Vol 34 (3) ◽  
pp. 326-333 ◽  
Author(s):  
Gisele Salgado Heckler ◽  
Roberto Munehisa Shimizu ◽  
Adilson Fransozo ◽  
Sergio Rosso ◽  
Rogerio Caetano da Costa
Keyword(s):  
Temporal Distribution ◽  
Southeastern Brazil ◽  
Spatial And Temporal Distribution ◽  
Xiphopenaeus Kroyeri

scholarly journals SEDIMENT DISTRIBUTION ANALYSIS IN BALOHAN BAY, SABANG

2017 ◽  
Vol 8 (2) ◽  
pp. 531
Author(s):  
Syahrul Purnawan ◽  
Tengku Putra Fajran Alamsyah ◽  
Ichsan Setiawan ◽  
. Rizwan ◽  
Maria Ulfah ◽  
...  
Keyword(s):  
Grain Size ◽  
Size Distribution ◽  
Statistical Approach ◽  
Fine Sand ◽  
Sieve Analysis ◽  
Distribution Analysis ◽  
Sediment Grain Size ◽  
Sediment Distribution ◽  
Sediment Properties ◽  
Aceh Province

<em>We investigated the sediment properties and distribution in Balohan Bay, which is located in southern Weh Island, Aceh Province. The aim of this research was to clarify the sediment distribution mechanism in the Balohan Bay using a statistical approach. Samples were collected on January 2016 using coring method. Sediment grain-size distribution from 14 stations was obtained using wet sieve analysis. A large amount of fine sand and very fine sand were found in Balohan Bay, as a result of several tributaries discharged in those areas. The sediment distribution in eastern stations showed an indication as a coarser size and a poorer sorted area, as they were adjacent to the steep cliff.</em>

scholarly journals SEDIMENT GRAIN-SIZE COMPOSITION IN LAKE ANASHKINO (SOUTH-WESTERN ONEGO AREA)

2021 ◽  
Vol 6(16) (4) ◽  
pp. 129-138
Author(s):  
N. A. Myasnikova
Keyword(s):  
Grain Size ◽  
Size Composition ◽  
Fine Sand ◽  
Coarse Silt ◽  
Low Velocity ◽  
Humid Climate ◽  
Sediment Grain Size ◽  
Grain Size Composition ◽  
Sediment Formation ◽  
Formation Pattern

The lithostratigraphy and grain-size composition of sediments in Lake Anashkino (south-western Onego area) are described. The younger, upper sediment layers showed a prevalence of very fine sand. Further down the sediment, there dominate coarse and medium silt fractions, and down from the depth of 10.03–10.16 m — medium and fine silt. The oldest sediments (at 10.19–10.20 m) feature a prevalence of very coarse and coarse silt, and further below (10.30–10.31 m) there prevail very fine sand and very coarse silt fractions. The prevalent activity in the palaeo-hydrodynamic environments in which the ancient sediments (9.96–10.31 m) were deposited was turbidite flows. Younger sediments (9.32–9.92 m) were deposited in the environment of low-velocity flows. The sediment formation pattern in Lake Anashkino during the change from a nival to a humid climate suggests there happened five shifts in dynamic water regimes.

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