Análise de dados de ecossondagem de fundo oriundos de cruzeiros realizados entre Fortaleza (CE) e Chuí (RS) com enfoque na morfologia e tipos de fundo

Cooke, Caroline Vieira; Madureira, Lauro Saint Pastous; Griep, Gilberto Henrique; Pinho, Marcelo Peres de

doi:10.1590/s0102-261x2007000400008

Cited by 12 publications

(13 citation statements)

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“…In the same region, [7] indicated the presence of phosphate deposits with a concentration of 15-16% of P 2 O 5 . Moreover, in recent studies based on echograms and high BSBS values, [18] and [19] suggested the presence of phosphatic deposits in the Rio Grande Terrace region.…”

Section: Discussionmentioning

confidence: 96%

3D bathymetry and bottom backscattering maps applied to identify potential phosphate deposits in the pelotas Basin, Brazil

Pinho

Madureira

Calliari

2015

2015 IEEE/OES Acoustics in Underwater Geosciences Symposium (RIO Acoustics)

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The Brazilian sector of the Pelotas Basin (PB) covers an area of 210,000 km², limited northwards by the Florianópolis High southwards by the boundary with Uruguay. The PB is economically and strategically important due to the presence of sub-surface mineral resources such as oil, natural and hydrate gas, as well as surface deposits, crusts and concretions of phosphorite (P 2 O 5 ), in addition the PB it is an important fishing ground. In this work bathymetric and Bottom Surface Backscattering Strength (BSBS) data were used from twenty hydroacoustic assessment surveys undertaken either to map pelagic fish or to evaluate the abundance of cetaceans in the PB. Bathymetry and BSBS were collected with a calibrated scientific echo-sounder SIMRAD EK500, operating at the frequency of 38 kHz. A total of 5,249,191 acoustic readings were processed from 15,367 nautical miles. Bathymetric data were integrated to satellite altimetry data in order to produce a 3D map aiming the identification of the main features in the region, such as the Rio Grande Valleys, the Rio Grande Cone, the Rio Grande Terrace and the terrace off Florianópolis. A BSBS map was also generated. The BSBS acoustic parameter is the ratio between incident and reflected energy by the seafloor and it is usually expressed on a logarithmic scale (dB). Bottom backscattered signal is influenced by physical, chemical and morphological characteristics of the seabed. Thus, BSBS can be used to identify different bottom types due to their different acoustic responses. In our analyses the PB showed intermediate BSBS values. Lower BSBS values, associated with finer sediment, predominated in the continental slope and oceanic areas, while high values, associated with coarse sediments, did not occupy large areas. The BSBS map was then superimposed on the 3D bathymetric map, allowing the identification of six areas associated with the presence of phosphorite in the PB, based on the high BSBS values and depth, suitable for the formation of phosphorite. Because of their genesis phosphorite deposits tend to exist in areas with high levels of organic matter, at depths of up to 1000 m, covering the edge of the continental shelf and upper slope, marginal plateaus and submarine banks. Potential areas were identified in the outer shelf on the Rio Grande Cone , on the outer shelf and slope off Mostardas-RS, on the Rio Grande Terrace and off Florianópolis-SC. All these areas have good correspondence with those identified by the Geological Survey of Brazil with the presence of calcareous deposits and phosphorite.

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Section: Discussionmentioning

confidence: 96%

3D bathymetry and bottom backscattering maps applied to identify potential phosphate deposits in the pelotas Basin, Brazil

Pinho

Madureira

Calliari

2015

2015 IEEE/OES Acoustics in Underwater Geosciences Symposium (RIO Acoustics)

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“…North unit: includes either shallow as deep fishing grounds, resulting in a highly diverse assortment of species exploited, as the narrowing of the shelf in the region (Cooke et al, 2007) makes it possible for the vessels to reach great depths in a short navigation time. Therefore, in the same fishing trip the fleet is able to exploit either coastal species as deeper ones.…”

Section: Discussionmentioning

confidence: 99%

Spatial management units for industrial demersal fisheries in southeastern and southern Brazil

Rosso¹,

Pezzuto²

2016

lajar

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ABSTRACT. Most fishing management systems in the world have long assessed and managed single-stocks over very large areas. The increasing use of the oceans and the problems faced by many fisheries have increased the trend to focus on spatial-based fisheries management. Most of the Brazilian industrial fisheries concentrate in the so-called "southeastern-south region" (SE/S), a large jurisdictional area exceeding 1600 km of latitudinal extent, along which industrial demersal fishing vessels operate quite unrestrictedly, resulting in large overlapping in their catch composition and fishing areas. Despite being essentially multi-specific, management of these fisheries is focused on a few target-species, with poor results in terms of sustainability. This paper aimed at identifying possible future spatial fishing management units for the region, based on the distribution of demersal stocks, depth, bottom characteristics and fishing dynamics from double-rig, pair and stern trawlers, bottom gillneters, bottom longliners and octopus potters which were landed in Santa Catarina harbors (southern Brazil) between 2010 and 2012. Based on these data and information from existing literature, six potential spatial units were proposed at coastal (<30 m depth), shelf (southeastern and southern sectors) (30 to 100 m), shelf break (100 to 250 m) and slope areas (>250 m). This new scheme represents a step forward in designing a final spatial management model for the SE/S industrial fisheries, improving a previous model published in the early 2000`s and conforming, in general, to the three main subdivisions recognized for the South Brazil Large Marine Ecosystem. Keywords: fishing management, marine spatial planning, demersal fisheries, industrial fisheries, ecosystem approach in fisheries, southeastern-south Brazil.Unidades de manejo espacial para las pesquerías demersales de la región sureste y sur de Brasil RESUMEN. En el mundo la mayoría de los sistemas de manejo de pesquerías han evaluado y manejado stocks únicos en extensas áreas. El aumento del uso de los océanos y los problemas enfrentados por muchas pesquerías han generado un enfoque creciente de atención en el manejo pesquero basado en áreas. La mayor parte de las pesquerías industriales brasileñas se concentra en la llamada "región sureste y sur" (SE/S), una gran área jurisdiccional que excede 1600 km de extensión latitudinal, donde los buques pesqueros involucrados en las pesquerías demersales industriales operan casi sin restricción, resultando en una gran superposición en la composición de capturas y áreas de pesca. Al ser éstas esencialmente multi-específicas, el manejo de estas pesquerías se basa en un grupo pequeño de especies objetivo con resultados pobres en términos de sustentabilidad. El artículo busca identificar posibles unidades de manejo pesquero espacial para la región, sobre la base de la distribución de los stocks demersales, profundidad y tipos de fondo, así como también en la dinámica de las flotas de arrastre dobles, arrastre simple, arrastre por parejas...

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“…In the south shelf-width attains 170 km at Rio Grande port. Mean depth at the South Brazilian continental shelf break is around 120 m (CORRÊA et al, 1996;COOKE et al, 2007).…”

Section: Introductionmentioning

confidence: 99%

“…Also in the same region, at around 500 m depth, Silva and Mello (2005) indicated the presence of phosphorite pockets with 15-16 % P2O5 content. Cooke et al (2007) suggested the presence of phosphate deposits in the region based on the features observed in echograms and high acoustic reflectivity values. Therefore, the high acoustic reflectivity of the Rio Grande Terrace observed on the acoustic map elaborated in the present study may be attributed to phosphate pockets, which are highly reflective surfaces.…”

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confidence: 96%

Seabed acoustic classification in the Pelotas basin, Brazil

2013

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A B S T R A C TThe present study sought to develop a seabed map of the region of the Pelotas Basin using acoustic methods. A total number of 1,507,823 seabed reflectivity data, collected during six oceanographic surveys, were processed to generate a seabed map. Data processing consisted of the classification of the acoustic parameter BSBS (Bottom Surface Backscattering Strength) obtained with the Scientific Echosounder EK 500 operating at a frequency of 38 kHz. BSBS is expressed in decibels (dB), and corresponds to a logarithm of the ratio between incident acoustic energy and the energy reflected by the seabed. Four BSBS value classes, associated with different sediment types, were established. High BSBS values are associated with coarse sediments, whereas low values indicate fine sediments. A seabed reflectivity map was generated using the Natural Neighbor method to interpolate the BSBS values organized according to the pre-established classes. Four features with high BSBS values were identified at 100-200 m depth. The largest one was found in the region of Santa Marta Cape and attributed mainly to consolidated seabed and/or the presence of biodetritic material, according to comparison with maps available in the literature. Above 500m depth, there was a predominance of acoustically low reflectivity sea floor, which was attributed to the presence of muddy sediment. Considering the lack of information on the seabed at great depths, the acoustic method was shown to be an alternative tool to obtain data on seabed characteristics in these regions.

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Análise de dados de ecossondagem de fundo oriundos de cruzeiros realizados entre Fortaleza (CE) e Chuí (RS) com enfoque na morfologia e tipos de fundo

Cited by 12 publications

References 2 publications

3D bathymetry and bottom backscattering maps applied to identify potential phosphate deposits in the pelotas Basin, Brazil

3D bathymetry and bottom backscattering maps applied to identify potential phosphate deposits in the pelotas Basin, Brazil

Spatial management units for industrial demersal fisheries in southeastern and southern Brazil

Seabed acoustic classification in the Pelotas basin, Brazil

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