255 resultados para BONGO
Resumo:
The standing stock of chlorophyll, the quantities of copepods collected with a 30 liter Niskin bottle and the standing stock of zooplankton collected with a 'Bongo' net were measured from 0 to 200 m depth during a cruise along 10' W from 1' N to 12' S. These parameters are correlated to hydrological conditions measured simultaneously. 6 zonal areas have been delimited and described; the north equatorial convergence, the northern flow of the south equatorial counter-current, the trade winds drift, the south equatorial counter-current and the Benguela's drift.
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The on-offshore distributions of tuna larvae in near-reef waters of the Coral Sea, near Lizard Island (14°30ʹS, 145°27ʹE), Australia, were investigated during four cruises from November 1984 to February 1985 to test the hypothesis that larvae of these oceanic fishes are found in highest abundance near coral reefs. Oblique bongo net tows were made in five on-offshore blocks in the Coral Sea, ranging from 0–18.5 km offshore of the outer reefs of the Great Barrier Reef, as well as inside the Great Barrier Reef Lagoon. The smallest individuals (<3.2 mm SL) of the genus Thunnus could not be identified to species, and are referred to as Thunnus spp. We found species-specific distributional patterns. Thunnus spp. and T. alalunga (albacore) larvae were most abundant (up to 68 larvae/100 m2) in near-reef (0–5.5 km offshore) waters, whereas Katsuwonus pelamis (skipjack tuna) larvae increased in abundance in the offshore direction (up to 228 larvae/100 m2, 11.1–18.5 km offshore). Larvae of T. albacares (yellowfin tuna) and Euthynnus affinis (kawakawa) were relatively rare throughout the study region, and the patterns of their distributions were inconclusive. Few larvae of any tuna species were found in the lagoon. Size-frequency distributions revealed a greater proportion of small larvae inshore compared to offshore for K. pelamis and T. albacares. The absence of significant differences in size-frequency distributions for other species and during the other cruises was most likely due to the low numbers of larvae. Larval distributions probably resulted from a combination of patterns of spawning and vertical distribution, combined with wind-driven onshore advection and downwelling on the seaward side of the outer reefs.
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Tuna larvae (at flexion, postflexion, and transformation stages) were collected by dip net and light traps at night in the northwestern Panama Bight during the season of reduced upwelling (June−September) of 1990, 1991, 1992, and 1997. The larvae were identified as yellowfin tuna (Thunnus albacares) by mtDNA analysis. Ichthyoplankton data from bongo and Tucker trawl tows were used to examine the potential prey abundance in relation to the mean size-at-age and growth rates of the yellowfin tuna larvae and their otoliths. The most rapid growth rates occurred during June 1990 when plankton volumes were at their highest levels. The lowest plankton volumes coincided with the lowest growth rates and mean sizes-at-age during the August−September 1991 period. High densities of larval fish were prevalent in the ichthyoplankton tows during the 1991 period; therefore intra- and interspecific competition for limited food resources may have been the cause of slower growth (density-dependent growth) in yellowfin tuna larvae The highest mean seasurface temperature and the lowest mean wind stress occurred during an El Niño-Southern Oscillation (ENSO) event during the 1997 period. There appeared to be no clear association between these environmental factors and larval growth rates, but the higher temperatures may have caused an increase in the short-term growth of otoliths in relat
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The present paper investigates the occurrence and abundance of brachyuran larvae in the Manora Channel during August- December 1993. The fortnightly planktonic sampling was carried out in Manora Channel which is bordered by mangroves, during day time from surface and subsurface waters at shallow depth using Bongo net of 300 micron mesh size. Analysis of samples revealed presence of brachyuran larvae of 12 species belonging to 6 families. Of these 4 species are confirmed: Serenella indica, Dotilla blanfordi, Metopograpsus thukuhar and Clistocoeloma lanatum, 2 provisionally identified species are: Pilumnus ?karachiensis and Pinnotheres ?pisum, 2 species are identified upto generic level: Philyra sp. and Pinnotheres sp., and 1 Ocypodid species and 3 Xanthid species are identified upto family level. This study based on identification, occurrence and abundance of brachyuran larvae in the area, also gives percentage composition of brachyuran larvae collected during 1993, in the Manora Channel.
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This study gives an account of distributional patterns of Brachyuran larvae in the Manora Channel from January to November 1995. The planktonic sampling was carried out during day time from surface and sub-surface waters of station I and II (certain sites) at shallow depths (15'-20') using Bongo net of 300 micron mesh size. In all 19527 larvae were obtained through fourteen sampling. These brachyuran larvae belonged to nine families and twenty four species: Ebalia sagittifera, Philyra sp., Philyra scabriuscula (Leucosiidae), Schizophyris aspera (Majidae), Charybdis annulata, Charybdis sp. (Portunidae), Xanthid sp A., B. and C. (Xanthidae), Pilumnus karachiensis, Pilumnus sp. (Pilumnidae), Menippe rumphii (Oziidae), Pinnotheres sp. A, and B. (Pinnotheridae), Nasima dotilliforme, Serenella indica, Macrophthalmus (Mareotis) depressus, Macrophthalmus sp., Dotilla blanfordi, Ocypodid sp. A., B. and C. (Ocypodidae), Metopograpsus thukuhar and Clistocoeloma lanatum (Grapsidae). This study is based on identification, occurrence, distributional patterns along Manora Channel and percentage composition of brachyuran larvae in the area, collected during 1995.
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A study was carried out in June/July 1996 in the River Po outflow in the northern Adriatic to investigate spawning of anchovy Engraulis encrasicolus and survival of larvae in relation to food availability and wind mixing. Hydrographic- and bongo net sampling was carried out on 2 grid surveys; one after a period of low winds and settled weather, and the other after an intervening period of strong winds, which resulted in a decrease in water column stratification. The spawning areas of anchovy and the larval distributions were associated with the river outflow plume (most clearly on the second survey grid, after the period of higher winds). Potential food particles for anchovy larvae, primarily copepod nauplii and copepodite stages, were also concentrated in the area influenced by the river outflow. Although there was a nearly 50% reduction in the mean water column abundance of potential food particles between the 2 survey grids, mostly due to a decline in abundance outside the immediate river plume area, there was no significant change in mortality of anchovy larvae between the 2 grids; the exponential decline in numbers of eggs and larvae to 10 mm in length being equivalent to overall mortality rates of 43.2%/d on the first survey and 44.7%/d on the second. The resilience of larval survival under potentially less favourable feeding conditions, following the period of wind mixing, was ascribed, in part, to the maintenance of local water column stratification by the superficial low salinity input from the River Po. This stratification in the immediate outflow area was associated with the presence of concentrated layers of potential food particles (typically >50 particles/L and 1.5 to 2.8 times the mean water column abundance) in the upper 10 m of the water column, coincident with peak numbers of anchovy larvae. However, since there was no evidence for lower larval survival in areas, less influenced by the immediate river outflow plume, a simple direct relationship between enhanced water column stability, improved feeding conditions and larval survival was not supported.
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Interannual and seasonal trends of zooplankton abundance and species composition were compared between the Bongo net and Continuous Plankton Recorder (CPR) time series in the Gulf of Maine. Data from 5799 Bongo and 3118 CPR samples were compared from the years 1978–2006. The two programs use different sampling methods, with the Bongo time series composed of bimonthly vertically integrated samples from locations throughout the region, while the CPR was towed monthly at 10 m depth on a transect that bisects the region. It was found that there was a significant correlation between the interannual (r = 0.67, P < 0.01) and seasonal (r = 0.95, P < 0.01) variability of total zooplankton counts. Abundance rankings of individual taxa were highly correlated and temporal trends of dominant copepods were similar between samplers. Multivariate analysis also showed that both time series equally detected major shifts in community structure through time. However, absolute abundance levels were higher in the Bongo and temporal patterns for many of the less abundant taxa groups were not similar between the two devices. The different mesh sizes of the samplers probably caused some of the discrepancies; but diel migration patterns, damage to soft bodied animals and avoidance of the small CPR aperture by some taxa likely contributed to the catch differences between the two devices. Nonetheless, Bongo data presented here confirm the previously published patterns found in the CPR data set, and both show that the abundance increase of the 1990s has been followed by average to below average levels from 2002 to 06.
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Early recruitment indices based on larval fish data from the Continuous Plankton Recorder (CPR) have the potential to inform stock assessments of Ammodytes marinus in the North Sea. We evaluate whether the CPR data are reliable for sandeel larvae. Spatially, CPR larval data were comparable with catches by dedicated larval samplers (Gulf and bongo nets) during ICES coordinated surveys in 2004 and 2009. ICES data are also used to explore environmental influences on sandeel distributions. Temporally, CPR data correlate with larval data from plankton surveys off Stonehaven (1999–2005), with sandeel 0-group trawl data at the east Fair Isle ground (since 1984), and with recruitment data (since 1983) for the Dogger Banks stock assessment area. Therefore, CPR data may provide an early recruit index of relative abundance for the Dogger Banks assessment area, where the majority of the commercial catch of A. marinus is taken, and the Wee Bankie area that is particularly important for seabird foraging. While warm conditions may stimulate the production of sandeel larvae, their natural mortality is typically greater, in the Dogger Banks and Wadden Sea areas, when the larvae are hatched in warm years and/or with abundant 1-year-old sandeel that are likely to be cannibalistic.
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Dissertação de mest., Aquacultura e Pescas (Pescas), Faculdade de Ciências e Tecnologia, Univ. do Algarve, 2010
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O presente trabalho foi realizado como parte integrante do mestrado em música da Escola Superior de Música de Lisboa (ESML), e procurou explorar a utilização de “novos ritmos” (Belling, 2010), sobretudo a polimetria em uma peça para piano e percussão intitulada de “Martulus”, com pequena influência de células rítmicas afro-brasileiras e composta durante o último semestre do mestrado. A polimétrica realiza-se na peça sobrepondo, em vários momentos, os diferentes instrumentos em compassos diferentes uns dos outros o que resulta no fato de as barras de compassos por vezes não serem simétricas e o primeiro tempo do compasso acontecer em vários momentos diferentes, os instrumentos que utilizam duas claves, como o piano e a marimba, puderam utilizar às vezes de compassos diferentes em cada clave de forma sobreposta. A peça termina com o compasso de 0/8 e sem barras de compasso, o 8 do denominador faz alusão as colcheias que passa a ser a única forma de guia para os instrumentistas e ausência de primeiro tempo deixando a música suspensa sem acentos implícitos. A peça foi composta para 7 instrumentistas e 7 instrumentos; piano, marimba, tímpano, bumbo grande, caixa, congas, bongôs, e da forma como foi escrita um mesmo percussionista não pode tocar mais do que um instrumento.
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A Costa Norte Brasileira é uma das regiões mais produtivas do Brasil, tendo o rio Amazonas como a principal fonte de nutrientes, o que explica o grande potencial de produção primária na região. O objetivo principal deste trabalho foi determinar a composição e variação nictimeral do ictioplâncton no estuário do rio Amazonas - Porto de Santana – Amapá - Brasil. As amostras de água subsuperficiais foram coletadas para aferir seguintes parâmetros: condutividade elétrica, pH, salinidade, turbidez, oxigênio dissolvido e temperatura .As amostragens foram realizadas em dois ciclos de 24 horas em uma estação fixa, em lua quarto crescente (Quadratura) e em lua cheia (sizígia). A coleta das amostras foi realizada com uma rede de plâncton, tipo Bongo com 0,60 m de abertura de boca, 1,50 m de comprimento e abertura de malha de 500 μm. Para determinar o volume de água filtrado foi acoplado à entrada da rede um fluxômetro mecânico, a amostra foi coletada acondicionada em potes e fixada com formol a 4%. Transportada para o Laboratório de Ecologia Aquática e Aqüicultura Tropical – LECAT, da Universidade Federal Rural da Amazônia – UFRA onde o ictioplâncton foi quantificado e identificado em nível de família. Foram quantificadas 2.776 larvas, destas, 842 foram amostradas na coleta realizada na maré de quadratura (lua crescente) e 1.924 larvas na maré de sizígia (Cheia). As larvas de peixes identificadas nas marés pertencem a sete famílias (Engraulidae, Gobiidae, Sciaenidae, Tetraodontidae, Eleotridae, Clupeidae Pristigasteridae). As famílias Clupeidae e Gobiidae ocorreram somente na maré de quadratura, enquanto que as famílias Pristigasteridae e Tetraodontidae ocorreram somente na maré de sizígia. Durante a maré de quadratura (Lua Crescente) a família mais abundante foi Engraulidae seguida por Sciaenidae e Pristigasteridae. Nas estações, a densidade variou de 137 larvas/ 100 m3 às 15h30min até 2.859 larvas/ 100 m3 na coleta das 12h30min. Para a época das amostragens há um padrão temporal de distribuição das larvas de peixe influenciado pelo período de coleta (noturno e diurno), sendo que os maiores valores ocorrem durante o dia. O elevado número de larvas registrado revelou que a área do estuário do rio Amazonas é utilizada como área de reprodução e berçário. Não há diferenças significativas na composição do ictioplâncton com a mudança da fase lunar.
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Tansania, Dar es Salaam, Swahili, Videofilme, Populärkultur, Bongo Flava, Hip Hop, Filmanalyse, Sprachanalyse, Swahili Slang, Kiswahili cha Mitaani, Codeswitching