scholarly journals Spatial And Temporal Distribution Patterns Of Larval Sciaenids In The Estuarine System And Adjacent Continental Shelf Off Santos, Southeastern Brazil

2014 ◽  
Vol 62 (2) ◽  
pp. 149-164 ◽  
Author(s):  
Renata Roque Porcaro ◽  
Maria de Lourdes Zani-Teixeira ◽  
Mario Katsuragawa ◽  
Cláudia Namiki ◽  
Márcio Hidekazu Ohkawara ◽  
...  
Keyword(s):  
Continental Shelf ◽  
Abiotic Factors ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Southeastern Brazil ◽  
Estuarine System ◽  
Frequency Of Occurrence ◽  
Reproductive Process ◽  
Average Abundance ◽  
Estuarine Region

Based on data collected during the project "The influence of the Santos-São Vicente estuarine system on the ecosystem of the adjacent continental shelf" (ECOSAN), from Nov/2004 to Mar/2006, the space-temporal distribution pattern of Sciaenidae larvae in relation to biotic and abiotic factors was investigated. Bongo net was used for sampling, aboard the R/V "Prof. W. Besnard" on the shelf, and the boats "Veliger II" and "Albacora" in the estuarine region. Twelve taxa were identified: Bairdiella ronchus, Ctenosciaena gracilicirrhus, Cynoscion spp., Isopisthus parvipinnis, Macrodon atricauda, Micropogonias furnieri, Menticirrhus spp., Nebris microps, Ophioscion punctatissimus, Paralonchurus brasiliensis, Stellifer rastrifer and Stellifer spp. Sciaenidae larvae were widespread on the continental shelf in both campaigns (frequency of occurrence >80%). They were most abundant in Mar/2006 (mean = 6.47 larvae.m-2; sd = 8.36) and least abundant in Sep/2005 (mean = 2.37 larvae.m-2; sd = 3.33). The average abundance in the estuarine region ranged from 0.12 larvae.m-2 (sd = 0.11) in Jun/2005 to 4.28 larvae.m-2 (sd = 1.99) in Nov/2004. Frequency of occurrence minimum occurred in Aug/2005 (50%) and the maximum in Nov/2004 (100%). The presence of Sciaenidae larvae in most locations and periods suggests that the reproductive process of this family in the region is continuous, spawning being more intense in the warmer months.

Structure and dynamics of Gobiidae larvae (Teleostei, Perciformes) in a tropical estuary: seasonal relationships with tidal cycles

2014 ◽  
Vol 94 (7) ◽  
pp. 1557-1568 ◽  
Author(s):  
Eduardo A.P. Gomes ◽  
Ana C.T. Bonecker
Keyword(s):  
Rainy Season ◽  
Fish Larvae ◽  
Abiotic Factors ◽  
River Estuary ◽  
River Mouth ◽  
Temporal Distribution ◽  
Mesh Size ◽  
Distribution Patterns ◽  
Flood Tide ◽  
Estuarine System

This study aims to describe the spatial and temporal distribution patterns of Gobiidae larvae at a tropical estuarine system in south-east Brazil (Macaé). The samples were collected in six stations, through oblique hauls using a bongo net (330 µm mesh size), coupled to a flowmeter, during the night in the ebb and flood tides in March, July and October 2006 and in February 2007. In the Macaé River estuary was collected a total of 1,234 Gobiidae larvae, representing nine taxa. The highest densities occurred in the river mouth during the flood tide in the rainy season. The most abundant groups were: Gobiosoma parri, Gobionellus oceanicus and Ctenogobius boleosoma. Gobiosoma parri was also dominant at the Macaé estuary, which also presented higher densities in the coastal stations during the rainy season (March), both the flood as the ebb tide. Gobionellus oceanicus and Ctenogobius boleosoma were characteristic of the dry season in the mouth and river stations during the flood tide. The abiotic factors chlorophyll-a and temperature were considered biologically significant for Gobiidae larvae distribution. The spatial and seasonal variations together with the tide influence the distribution of the fish larvae Gobiidae family in the Macaé River estuary and its coastal zone.

Low-frequency sounds emitted by Sotalia fluviatilis guianensis (Cetacea: Delphinidae) in an estuarine region in southeastern Brazil

2001 ◽  
Vol 79 (1) ◽  
pp. 59-66 ◽  
Author(s):  
Emygdio LA Monteiro-Filho ◽  
Karin DKA Monteiro
Keyword(s):  
Social Structure ◽  
Low Frequency ◽  
Southeastern Brazil ◽  
Frequency Of Occurrence ◽  
Emission Rates ◽  
Fourth Class ◽  
The Social ◽  
Sotalia Fluviatilis ◽  
Estuarine Region ◽  
Made In

Recordings of the vocalizations of the dolphin Sotalia fluviatilis guianensis were made in an estuarine complex at Cananéia in southeastern Brazil over a period of 10 years (1989–1998). This area is characterized by mangroves and the constant presence of dolphins. Recordings were obtained at depths of 2–4 m using digital and analog recorders at a speed of 19 cm/s. Four classes of sounds were identified. "Whistles," which are used in social activities, occurred with the greatest frequency (χ2 = 58.92, df = 3, P < 0.001). "Calls," which were very variable in form, were the second most common class used by family groups (χ2 = 10.96, df = 2, 0.005 > P > 0.001). There were no differences in the rates at which schools emitted whistles and calls (χ2 = 2.12, df = 1, 0.25 > P > 0.10). "Gargles" were apparently emitted by calves and were similar in structure to a low-frequency call. The fourth class, "clicks," are used in echolocation. Clicks varied considerably in their frequency of occurrence and frequency of emission, and were not always detected. There were significant differences in emission rates among the four classes (χ2 = 18.73, df = 3, P < 0.001). In addition, which class of sound was emitted depended on the type of activity exhibited by the dolphins (displacement, fishing, social) and on the social structure (family or school) adopted.

scholarly journals Bio-Optical Properties of the Inner Continental Shelf off Santos Estuarine System, Southeastern Brazil, and their Implications for Ocean Color Algorithm Performance

2014 ◽  
Vol 62 (2) ◽  
pp. 71-87 ◽  
Author(s):  
Melissa Carvalho ◽  
Aurea Maria Ciotti ◽  
Sônia Maria Flores Gianesella ◽  
Flávia Marisa Prado Saldanha Corrêa ◽  
Rafael Riani Costa Perinotto
Keyword(s):  
Continental Shelf ◽  
Light Absorption ◽  
Ocean Color ◽  
Southeastern Brazil ◽  
Optical Parameters ◽  
Estuarine System ◽  
Strongly Correlated ◽  
Algorithm Performance ◽  
Biochemical Processes ◽  
Inner Continental Shelf

Optical characterizations of coastal water masses are important tools for a better understanding of physical and biochemical processes and aid the optimization of ocean color algorithms. In this study we present three optical classes of water observed during October/2005 and March/2006 on the inner continental shelf adjacent to Santos Bay (Brazil), based on remote sensing reflectance. ANOVA indicated a crescent estuarine influence in classes 1 to 3. Class 3 presented the highest chlorophyll-a and nutrient concentration and highest light absorption coefficients. Colored dissolved organic matter (CDOM) dominated the light absorption in all classes and was strongly correlated to salinity in October/2005 due to the influence of the La Plata plume. The results indicated that CDOM dynamics in the Santos inner shelf are very complex. The performance of global chlorophyll algorithms was significantly smaller for October/2005 than for March/2006. As inconsistent changes in light absorption spectra by phytoplankton were detected between samplings, the results show that future bio-optical algorithms for this region must be optimized preferentially considering CDOM optical parameters.

scholarly journals Diel variation of fish community in sandy beaches of southeastern Brazil

2008 ◽  
Vol 56 (1) ◽  
pp. 23-39 ◽  
Author(s):  
Luiz Ricardo Gaelzer ◽  
Ilana R. Zalmon
Keyword(s):  
Fish Community ◽  
Surf Zone ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Sandy Beaches ◽  
Southeastern Brazil ◽  
Diel Variation ◽  
Fish Community Structure ◽  
Pomatomus Saltatrix ◽  
Number Of Species

Fish living in coastal waters present behavior patterns ruled by environmental light levels. Diel variations in fish community structure were investigated at Arraial do Cabo surf zone (22º58'S, 42º01'W). From September/2001 to August/2002 monthly sampling consisted of 12 hauls of a beach seine during the day and at night at Praia dos Anjos, Praia Grande and Prainha beaches. Different temporal distribution patterns of the ichthyc community were recorded. At Praia dos Anjos, total richness was higher at night while the average number of species, CPUE, Margalef's richness and Shannon diversity were generally higher during the day. We believe that this pattern was caused by the displacement of some species such as Harengula clupeola,Trachinotus carolinus and Umbrina coroides at night to deeper areas searching for food or for predator avoidance. At Praia Grande and Prainha the average number of species, CPUE, richness and diversity indexes were generally higher at night with the dominant species H. clupeola, Pomatomus saltatrix and Sardinella brasiliensis. It is suggested that the main factor to diel variation is the protection against predators due to darkness, making visualization of the prey difficult, besides the presence of seasonal macroalgae beds at Prainha, which might function as a food area for piscivorous fishes due to the proximity of larger individuals in shallower water especially at night.

Abundance Estimates of Guiana Dolphins (Sotalia guianensis; Van Bénéden, 1864) Inhabiting an Estuarine System in Southeastern Brazil

2019 ◽  
Vol 45 (1) ◽  
pp. 56-65 ◽  
Author(s):  
Aline B. de Mello ◽  
Julia M. B. Molina ◽  
Maja Kajin ◽  
Marcos C. de O. Santos
Keyword(s):  
Southeastern Brazil ◽  
Estuarine System ◽  
Sotalia Guianensis ◽  
Abundance Estimates

scholarly journals Intra-Storm Pattern Recognition through Fuzzy Clustering

Hydrology ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. 57
Author(s):  
Konstantinos Vantas ◽  
Epaminondas Sidiropoulos
Keyword(s):  
Fuzzy Clustering ◽  
A Priori ◽  
Temporal Distribution ◽  
Distribution Patterns ◽  
Rainfall Data ◽  
Rainfall Runoff ◽  
Domain Specific ◽  
Runoff Modeling ◽  
National Bank ◽  
Rainfall Patterns

The identification and recognition of temporal rainfall patterns is important and useful not only for climatological studies, but mainly for supporting rainfall–runoff modeling and water resources management. Clustering techniques applied to rainfall data provide meaningful ways for producing concise and inclusive pattern classifications. In this paper, a timeseries of rainfall data coming from the Greek National Bank of Hydrological and Meteorological Information are delineated to independent rainstorms and subjected to cluster analysis, in order to identify and extract representative patterns. The computational process is a custom-developed, domain-specific algorithm that produces temporal rainfall patterns using common characteristics from the data via fuzzy clustering in which (a) every storm may belong to more than one cluster, allowing for some equivocation in the data, (b) the number of the clusters is not assumed known a priori but is determined solely from the data and, finally, (c) intra-storm and seasonal temporal distribution patterns are produced. Traditional classification methods include prior empirical knowledge, while the proposed method is fully unsupervised, not presupposing any external elements and giving results superior to the former.

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.

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