Spelling suggestions: "subject:"ichthyofauna."" "subject:"ichthyofaunal.""
81 |
Caracterização ecomorfológica da comunidade de peixes de duas microbacias do Alto Rio ParanáOliveira, Elisa Martins de 09 March 2016 (has links)
Submitted by Alison Vanceto (alison-vanceto@hotmail.com) on 2017-02-07T10:30:44Z
No. of bitstreams: 1
TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-02-08T12:04:18Z (GMT) No. of bitstreams: 1
TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Approved for entry into archive by Camila Passos (camilapassos@ufscar.br) on 2017-02-08T12:08:38Z (GMT) No. of bitstreams: 1
TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5) / Made available in DSpace on 2017-02-08T12:10:27Z (GMT). No. of bitstreams: 1
TeseEMO.pdf: 7148427 bytes, checksum: 475fdc271961e45dfdde88a0decfaf60 (MD5)
Previous issue date: 2016-03-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / This study examined the ecomorphological pattern ofichthyofauna in two watersheds
located on the Upper Paraná River. It was analyzed the ecomorphological variations of
species collected from the Beija-Flor stream and Beija-Flor reservoir located in Estação
Ecológica de Jataí and Lapa stream located in Área de Proteção Ambiental
Corumbataí/Botucatu/Tejubá, to verify interspecific morphological differentiation, the
effects oftrophic guilds along the ecomorphological patterns and the effects of water
velocity along the ecomorphological standards. Of individuals collected in Estação
Ecológica de Jataí, it was selected two Characidium species, on which the
ecomorphological variations related to possibility of inter specific morphological
differentiation of species of the same genus were analyzed. Considering the common
species between the Estação Ecológica de Jataí and the Lapa Stream were observed
morphological variables in order to verify the intraspecific morphological differences.
Finally these results were related to the meaningof the relation ship between form and
function. The main morphological differences found in the individuals of this study
were related to the speed of water and feeding habits of the species. The distribution of
species in morphological space showed the relation between the ecomorphological
attributes and the distribution of species over the water column, where it was possible to
characterize the species as demersal, nectobenthicand nektonic species. The relation
ship of fish morphology with the water velocity is fundamental. The feeding also
contributes with smaller importance in the separation of species in ecomorphological
space, but this contribution seems to be because of the presence of these food items is
also influenced by the speed of the water. The function of the species in the
environmentin which they liveis linked mainly to its trophicniche. / Neste estudo foi analisado o padrão ecomorfológico daictiofauna de duas microbacias
localizadas no alto rio Paraná. Foram analisadas as variações ecomorfológicas das
espécies coletadas no córrego e represa do Beija-Flor, localizados na Estação Ecológica
de Jataí e córrego da Lapa, localizado na Área de Proteção Ambiental
Corumbataí/Botucatu/Tejubá, para verificar as diferenças morfológicas interespecíficas,
os efeitos das guildas tróficas junto aos padrões ecomorfológicos e os efeitos da
velocidade da água junto aos padrões ecomorfológicos. Das espécies coletadas na
Estação Ecológica de Jataí, foram selecionadas duas do gênero Characidium, sobre as
quais foram analisadas as variações ecomorfológicas relacionadas à possibilidade de
existência de diferenciação morfológica interespecífica de espécies pertencentes ao
mesmo gênero. Considerando-se as espécies comuns entre a Estação Ecológica de Jataí
e o córrego da Lapa, foram observadasas variáveis morfológicas com objetivo
deverificar as diferenciações morfológicas intraespecíficas. Por fim, tais resultados
foram relacionados ao significado da relação entre forma e função. As principais
diferenças morfológicas encontradas nos indivíduos deste estudo foram relacionadas à
velocidade da água e ao hábito alimentar das espécies. A distribuição das espécies no
espaço morfológico mostrou a relação entre os atributos ecomorfológicos e a
distribuição das espécies ao longo da coluna da água, que possibilitou caracterizar as
espécies como demersais, nectobentônicas e nectônicas. A relação da morfologia dos
peixes com a velocidade da água mostrou-se fundamental. A alimentação aparece com
menor importância na separação das espécies no espaço ecomorfológico, mas tal
contribuição parece ocorrer devido à presença destes itens alimentares serem
influenciados pela velocidade da água. A função das espécies no ambiente em que
habitam está ligada, principalmente, ao seu nicho trófico.
|
82 |
Biodiversidade e abund?ncia da ictiofauna associada ao cultivo org?nico de Litopenaeus vannamei (Boone, 1931)Costa J?nior, Marcos Ant?nio Freire da 13 December 2006 (has links)
Made available in DSpace on 2014-12-17T14:02:04Z (GMT). No. of bitstreams: 1
MarcosAFCJ.pdf: 1873191 bytes, checksum: 35fd621d2a3584a9f759dfe902f57bce (MD5)
Previous issue date: 2006-12-13 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / The expansion of shrimp farming has caused a series of environmental impacts, often as a result of lack of planning and adequate management. Organic aquaculture has emerged as an alternative to conventional shrimp farming, and differently, aims at the economical, ecological and farming potential of other organisms, such as fishes, oysters and seaweeds. The present study aimed at evaluating the biological diversity and abundance of the ichthyofauna associated to Litopenaeus vannamei organic culture at PRIMAR farm (Rio Grande do Norte, Brazil). The sampling period consisted of four culture cycles (1, 2, 3, and 4) accomplished in four grow-out ponds (V1, V7, V2,
and V4) in 2005. The first two culture cycles were carried out during the rainy season, and the last two cycles, during the dry season. Environmental (temperature, salinity,
transparency, and rainfall), biodiversity (diversity and uniformity and abundance indexes) of the ichthyofauna, and shrimp productivity data were collected throughout
these four culture cycles. The results obtained for the environmental variables showed that both salinity and transparency oscillated in a significant way (p < 0.001) between culture cycles. In relation to the abundance of the ichthyofauna, fifty four species associated to the organic culture of Litopenaeus vannamei were collected and
identified at PRIMAR. For the biodiversity criterion, larger species richness (S = 46) and uniformity (E = 0.59 ? 0.16) were observed during cycles 3 and 4 than in cycles 1
and 2 (S = 41 and E = 0.15 ? 0.12). A positive and significant correlation was obtained for the transparency with diversity and uniformity of fish species between cycles 1 and
2 (wet season) and cycles 3 and 4 (dry season) (p < 0.017 - Shannon Index; p < 0.008 - Pielou Index, respectively). A correlation could not be established between shrimp
productivity and fish biomass. However, fish biomass decreased from cycles 1 and 2 to cycles 3 and 4, concomitant with an increase in shrimp productivity, most probably due to a higher (from 58.0% to 71.0%) shrimp survival. Regarding the culture potential of the ichthyofauna, three species (Mugil curema, Mugil liza and Chaetodipterus faber) were identified as potential farming alternatives, either singly or in consortium with Litopenaeus vannamei. A fourth species (Centropomus undecimalis) was indicated as
an alternative for single culture or in consortium with other fish species. In conclusion, the large diversity of estuarine fishes associated to Litopenaeus vannamei farming observed at PRIMAR clearly indicated the ecological feasibility for organic aquaculture in northeastern Brazil / A expans?o da carcinicultura tem ocasionado uma s?rie de impactos ambientais, frequentemente, como conseq??ncia da falta de planejamento e gerenciamento adequados. A aq?icultura org?nica tem sido apontada como alternativa
? carcinicultura convencional e apresenta como diferencial, o aproveitamento do potencial econ?mico, ecol?gico e de cultivo de outros organismos, tais como peixes, ostras e macroalgas. O objetivo do presente estudo foi avaliar a diversidade biol?gica e abund?ncia da ictiofauna associada ao cultivo org?nico de Litopenaeus vannamei na fazenda PRIMAR (Rio Grande do Norte, Brasil). O per?odo amostral consistiu de
quatro ciclos de cultivo (1, 2, 3 e 4) realizados em quatro viveiros de engorda (V1, V7, V2 e V4) em 2005. Os dois primeiros ciclos foram realizados durante a esta??o chuvosa e os dois ?ltimos, durante a estiagem. Dados ambientais (temperatura, salinidade, transpar?ncia e precipita??o pluviom?trica), da diversidade biol?gica (?ndices de diversidade, uniformidade e abund?ncia) da ictiofauna, e da produtividade de camar?o foram coletados nesses quatro ciclos de cultivo. Os resultados obtidos para as vari?veis ambientais mostraram que a salinidade e a transpar?ncia oscilaram de forma significativa (p < 0,001) entre os ciclos de cultivo. Em rela??o ? abund?ncia da ictiofauna, foram coletadas e identificadas cinq?enta e quatro esp?cies associadas ao cultivo org?nico de Litopenaeus vannamei na PRIMAR. Foram observadas maior riqueza (S = 46) e uniformidade (E = 0,59 ? 0,16) das esp?cies de peixe durante os ciclos 3 e 4 do que nos ciclos 1 e 2 (S = 41 e E = 0,15 ? 0,12). Correla??o positiva e significativa foi obtida para o aumento da transpar?ncia com a diversidade e uniformidade das esp?cies de peixe entre os ciclos 1 e 2 (esta??o chuvosa) e 3 e 4 (esta??o seca) (p < 0,017 - ?ndice de Shannon; p < 0,008 - ?ndice de Pielou, respectivamente). N?o houve correla??o entre a produtividade de camar?o e a
biomassa de peixes. No entanto, a biomassa de peixes aumentou no transcorrer dos ciclos 1 e 2 para 3 e 4, concomitante com um incremento na produtividade de
camar?o, decorrente provavelmente, de uma maior sobreviv?ncia (de 58,0% para 71,0%) desse crust?ceo. Em rela??o ao potencial de cultivo da ictiofauna, tr?s esp?cies (Mugil curema, Mugil liza e Chaetodipterus faber) foram identificadas como alternativas para cultivo isolado ou em cons?rcio com Litopenaeus vannamei. Uma quarta esp?cie (Centropomus undecimalis) foi apontada como alternativa para cultivo isolado ou em cons?rcio com outras esp?cies de peixe. Em conclus?o, a rica diversidade de peixes estuarinos associada ao cultivo de Litopenaeus vannamei observada na PRIMAR indica claramente, a viabilidade ecol?gica da aq?icultura org?nica no nordeste do Brasil
|
83 |
Invent?rio das esp?cies de peixes da costa do Estado do Rio Grande do Norte e aspectos zoogeogr?ficos da ictiofauna recifal do Oceano Atl?nticoGarcia J?nior, Jos? 04 May 2006 (has links)
Made available in DSpace on 2014-12-17T14:02:05Z (GMT). No. of bitstreams: 1
JoseGJ.pdf: 808378 bytes, checksum: 5bcac6baa0f225c071f882f6f3c2b442 (MD5)
Previous issue date: 2006-05-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior / We present a checklist of the shores fishes of the coast of the Rio Grande do Norte state. Species were registered through the specimens collection, underwater records, samples in landings of artisanal fleet and by compilation of data from literature and ichthyologic collections, between January 2004 to 2006. A total of 440 species form 2 classes, 25 orders, 106 families and 253 genus were registered. It is believed that due the great increase of the number of species registered, the ichthyofauna of the coast of this state is reasonably known / Considerando a reconhecida import?ncia envolvendo o conhecimento acerca da biodiversidade, o objetivo do presente trabalho foi realizar um invent?rio detalhado das esp?cies de peixes presentes na costa do Estado do Rio Grande do Norte. As esp?cies foram assinaladas atrav?s da coleta de exemplares, registros fotogr?ficos, acompanhamentos dos desembarques da frota pesqueira artesanal, consulta ?s bases de dados de cole??es cient?ficas e registros de literatura, durante o per?odo de janeiro de 2004 a janeiro de 2006. Foi registrada a ocorr?ncia de 2 classes, 25 ordens, 106 fam?lias, 253 g?neros e 440 esp?cies de peixes. Acredita-se que devido o grande aumento no n?mero de esp?cies registradas na costa do Estado do Rio Grande do Norte, sua ictiofauna encontra-se razoavelmente conhecida
|
84 |
Interações tróficas de representantes da ictiofauna introduzida e nativa, na fase jovem, em lagos do Vale do rio Doce - MG / Trophic interactions of introduced and native ichthyofauna juvenile representatives, in Vale do rio Doce lakes, Minas Gerais StateAnelise Marcos de Assumpção 24 March 2005 (has links)
Estudos realizados no sistema lacustre do Vale do rio Doce revelam um empobrecimento da ictiofauna após a introdução das espécies alóctones tucunaré (Cichla ocellaris) e piranha (Pygocentrus nattereri). Estas espécies, na fase adulta, não apresentam nenhum predador ou competidor efetivo nos ambientes estudados. Neste contexto e visando contribuir para medidas de manejo e prevenção de impactos com a introdução de espécies, este estudo objetivou conhecer a alimentação e avaliar, por meio de experimentos em laboratório, a seletividade alimentar e eficiência de alevinos destas duas espécies introduzidas na captura de invertebrados planctônicos comparadas a Astyanax cf bimaculatus e Geophagus brasiliensis (espécies nativas). Os alevinos, capturados em diferentes lagoas, foram medidos, pesados e tiveram seus estômagos analisados. A seletividade alimentar foi calculada através do índice de seletividade qualitativa de IVLEV (1961) e o índice da razão de procura por alimento (FRi) de Edmondson e Winberg (1971). A eficiência alimentar dos alevinos foi calculada e comparada através das taxas de predação. G. brasiliensis, A. cf bimaculatus e C. ocellaris apresentaram alimentação variada, baseada em itens de origem animal e vegetal. G. brasiliensis apresentou maior variação de itens alimentares baseado principalmente em organismos zooplânctônicos, enquanto C. ocellaris e A. cf bimaculatus consumiram essencialmente insetos. Os coeficientes de sobreposição alimentar foram significativos para G. brasiliensis, A. cf bimaculatus e C. ocellaris, indicando elevada similaridade na alimentação destas espécies. Entretanto, não foram significativos para P. nattereri, devido ao hábito exclusivamente carnívoro, desde a fase jovem. As taxas de predação diferiram significativamente na presença de outros alevinos e em diferentes concentrações de presas. Os alevinos de C. ocellaris, P. nattereri e A. cf bimaculatus foram mais eficientes na captura de presas ágeis, tais como copépodos adultos, comparados a G. brasiliensis, indicando boa adaptação na detecção, caça e sucesso na perseguição da presa, desde a fase jovem. A diversidade de peixes, amostrados na fase de alevinos, foi baixa nos diferentes ambientes estudados, não tendo sido coletadas espécies nativas nos lagos com presença de espécies introduzidas, indicando que as espécies nativas tem sido afetadas não apenas pela presença de competidores, mas também de predadores, desde a fase jovem. / Studies accomplished in the lacustrine environment of Vale do rio Doce show a decrease of the ichthyofauna after introduction of the aloctone species tucunaré (Cichla ocellaris) and piranha (Pygocentrus nattereri). These species, in mature phase, do not present any predators or effective competitors in the studied environment. In this context, and aiming to contribute to management and impact prevention measures concerning species introduction, this study was carried out to know the feeding habits and evaluate, through laboratory experiments, the feeding selectivity and efficiency of alevins of these introduced species in capturing planktonic invertebrates, compared to Astyanax cf bimaculatus and Geophagus brasiliensis (native species). The alevins, captured in different lakes, were measured, weighed and had their stomach analyzed. The feeding selectivity was calculated through the Ivlev (1961) qualitative selectivity rate, and the food searching reason rate (FRi) by Edmondson e Winberg (1971). The alevins feeding efficiency was calculated and compared through the predation rates. G. brasiliensis, A cf bimaculatus and C. ocellaris presented varied nutritional habits, based on both animal and vegetal items. G. brasiliensis presented more variation of food items based mainly on zooplanktonic organisms, while C. ocellaris and A cf bimaculatus consumed insects essentially. The feeding superposition coefficients were significative for G. brasiliensis, A. cf bimaculatus and C. ocellaris, indicating high similarity in their nutritional habits. However, they are not significative for P. nattereri, due to their exclusive carnivore habit since their juvenile phase. The predation rates differed significantly in presence of other alevins and in different prey concentrations. The C. ocellaris, p. nattereri and A. cf bimaculatus alevins were more efficient when capturing agile preys, such as adult copepods, compared to G. brasiliensis, indicating good adaptation for detecting, hunting and capturing prey since their juvenile phase. The diversity of fish, sampled in the alevin phase, was low in the different lakes studied, and native species were not collected in the lakes with introduced species, indicating that the native species have been affected not only by competitors, but also by predators\' presence, ever since their juvenile phase.
|
85 |
Fator de condição de peixes do sistema do Lago Grande, Manacapuru, AmazonasBarbosa, Heitor Thury Barreiros 11 April 2013 (has links)
Submitted by Geyciane Santos (geyciane_thamires@hotmail.com) on 2015-12-07T21:26:04Z
No. of bitstreams: 1
Dissertação - Hietor Thury Barreiros Barbosa.pdf: 1175425 bytes, checksum: 8796f8dda2460d2eda8171dbac3181a4 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-19T19:01:05Z (GMT) No. of bitstreams: 1
Dissertação - Hietor Thury Barreiros Barbosa.pdf: 1175425 bytes, checksum: 8796f8dda2460d2eda8171dbac3181a4 (MD5) / Approved for entry into archive by Divisão de Documentação/BC Biblioteca Central (ddbc@ufam.edu.br) on 2016-01-19T19:02:23Z (GMT) No. of bitstreams: 1
Dissertação - Hietor Thury Barreiros Barbosa.pdf: 1175425 bytes, checksum: 8796f8dda2460d2eda8171dbac3181a4 (MD5) / Made available in DSpace on 2016-01-19T19:02:23Z (GMT). No. of bitstreams: 1
Dissertação - Hietor Thury Barreiros Barbosa.pdf: 1175425 bytes, checksum: 8796f8dda2460d2eda8171dbac3181a4 (MD5)
Previous issue date: 2013-04-11 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Marked by a well defined alternation between the terrestrial and aquatic stages, the Amazon floodplain has a low climatic seasonality, with daily oscillations on temperature higher than annual and less pronounced variation of the photoperiod throughout the year. These environments are also characterized by the standard uni-modal and predictable flood with large seasonal variation in water level. For the fish fauna of the floodplain, the direct effects of changes in water level include severe changes in community composition and density of the population, conditioned by changes in limnological characteristics and the availability of food. Such seasonal variations in terms of feeding and reproductive responses may be expressed by the condition factor, quantitative indicator of the wellfare in front of the fish conditions of their environment. This study aimed to provide information on the seasonal variation of fish species condition factor in the Jaitêua and São Lourenço lakes that composes the Lago Grande System in the city of Manacapuru, Amazonas State. Data collect were made monthly for the period from July 2006 to July 2007. Once the condition factor were calculated, the comparisons between periods were performed by ANOVA. The comparisons between sexes and between juveniles and adults were made by t test. PCA was used to identify groups of species whose pattern of variation of the condition factor is similar. After critical data analysis, there were selected 13 species to study. The seasonal variation of the condition factor was significant for Acestrorhynchus falcirostris, Triportheus albus, Triportheus auritus, Potamorhina altamazonica, Potamorhina latior, Pygocentrus nattereri, Serrassalmus altispinis, Pellona flavipinnis and Hypophthalmus marginatus. Only Schizodon fasciatus, Serrassalmus spilopleura, Plagioscion squamosissimus and Hoplosternum littorale showed no seasonal variation in the condition factor. Despite the influence of reproductive characteristics, we can point at feeding habits as a biological trait that best explained the seasonal variation of the condition factor of fish species in the study area. Based on the local history, the hydrological cycle was considered atypical during the study period. Also, it was observed differences between cycles in the lake and in the main river. For most of the selected species, male and female seasonal variation in the condition factor showed similarities. Comparing juveniles and adults, the variation patterns of the two groups were different for the vast majority of species. / Marcada por uma alternância bem definida entre as fases terrestre e aquática, a várzea amazônica apresenta baixa sazonalidade climática, com oscilações diárias da temperatura superiores à anual e variação pouco pronunciada do fotoperíodo ao longo do ano. Esses ambientes são também caracterizados pelo padrão unimodal e previsível das enchentes com grande variação sazonal do nível da água. Para a ictiofauna da várzea, os efeitos diretos da variação do nível da água incluem severas modificações na composição das comunidades e na densidade das populações, condicionadas pelas alterações nas características limnológicas e na disponibilidade de alimentos. Tais variações sazonais, em termos de alimentação e respostas reprodutivas, podem ser expressas pelo fator de condição, indicador quantitativo do grau de bem-estar do peixe frente às condições de seu ambiente. Esse estudo visou gerar informações sobre a variação sazonal do fator de condição de espécies ictíicas nos lagos Jaitêua e São Lourenço, que compõem o Sistema do Lago Grande no município de Manacapuru, Estado do Amazonas. As coletas dos dados foram efetuadas mensalmente entre o período de Julho de 2006 e Julho de 2007. Calculado o fator de condição, as comparações entre períodos foram realizadas por métodos de ANOVA. Comparações entre sexo e entre juvenis e adultos foram feitas por teste t. Utilizou-se de PCA para identificar grupos de espécies com semelhanças na variação sazonal do fator de condição. Após análise crítica dos dados, foram selecionadas 13 espécies para estudo. A variação sazonal do fator de condição foi significante para Acestrorhynchus falcirostris, Triportheus albus, Triportheus auritus, Potamorhina altamazonica, Potamorhina latior, Pygocentrus nattereri, Serrassalmus altispinis, Pellona flavipinnis e Hypophthalmus marginatus. Apenas Schizodon fasciatus, Serrassalmus spilopleura, Plagioscion squamosissimus e Hoplosternum littorale não apresentaram variação sazonal. Apesar da influência de características reprodutivas, pode-se apontar o hábito alimentar como característica biológica que melhor explicou a variação sazonal do fator de condição das espécies ictíicas na área de estudo. Com base em séries históricas da localidade, o ciclo hidrológico foi considerado atípico durante o período de coleta. Observaram-se também diferenças entre ciclos no lago e no rio principal. Para a maioria das espécies selecionadas, machos e fêmeas apresentam variação sazonal no fator de condição semelhante. Comparando juvenis e adultos, os padrões de variação desses dois grupos foram diferentes para a grande maioria das espécies
|
86 |
Researches regarding the evolution, magnitude and complexity of the impact generated by the economic activities on the East Jiu RiverSimion, Alexandru Florin 07 July 2023 (has links)
Ongoing development of modern society, based on consumption of goods and services, leads to the increase of compulsoriness of economic agents to face market requirements by increasing the degree of local and regional industrialization. Establishment of new economic activities generates negative pressures on the environment and surface waters, generating increased pollution, manifested by vulnerability of aquatic ecosystems to stressors.
Preliminary studies carried out within the doctoral thesis entitled 'Research on the evolution, magnitude and complexity of the impact of economic activities on the East Jiu' include information on characteristic elements of the East Jiu River basin, in accordance with the Water Framework Directive 2000/60/CE.
The objectives of the field research aimed to identify economic activities in the eastern Jiu Valley generating an impact on the environment (especially the mining industry, but also timber exploitation and processing, local agriculture, animal husbandry and waste storage), establishing a quarterly monitoring program of the river basin, identification of flora and fauna species and identification of areas vulnerable to potential pollution.
Based on observations made in situ and on information obtained from the evolution process of the monitoring program, the appropriate methodologies for assessing physical-chemical and ecological quality of the water were selected.
Study of the evolution of the impact generated by economic activities on the East Jiu was carried out by mathematical modelling, with finite volumes, of the East Jiu River basin and plotting of pollutant dispersion maps. The magnitude and complexity of impact generated by economic activities was studied by using a complex system based on fuzzy logic, designed based on interactions between natural and artificial systems, between physical-chemical indicators of water and ecosystem. The research carried out substantiates in development of necessary technical measures to reduce the impact generated by economic activities located in eastern Jiu Valley, without significantly changing the hydrodynamics of the river basin.
Following research, during different research stages, methods, techniques and tools were designed and accomplished with the help of which, water and aquatic ecosystems’ quality can be assessed, as well as the impact generated by human activity on the Jiu River, at a given moment and/or continuously.:CONTENT
ACKNOWLEDGEMENTS
SUMMARY
LIST OF FIGURES
LIST OF TABLES
ABBREVIATIONS
INTRODUCTION
PURPOSE OF THE THESIS AND RESEARCH METHODOLOGY
CHAPTER 1 THE EAST JIUL RIVER HYDROGRAPHIC BASIN
1.1. Soil and subsoil of the Eastern part of Jiu Valley
1.2. Climate description of the Eastern part of Jiu Valley
1.3. Geology particularities of the Eastern part of Jiu Valley
1.4. Groundwater features of the Eastern part of Jiu Valley
1.5. Flora and fauna of the Eastern part of Jiu Valley
CHAPTER 2 SOURCES OF IMPACT ON THE QUALITY OF WATER, RIPARIAN, TERRESTRIAL AND AQUATIC ECOSYSTEMS
2.1. Mining industry
2.2. Wood processing industry in the Eastern part of Jiu Valley
2.3. Urban agriculture and local animal husbandry
2.4. Inappropriate urban household waste storage
CHAPTER 3 MONITORING PROGRAM AND METHODS OF EVALUATION OF THE QUALITY OF THE EAST JIUL RIVER
3.1. Establishment of monitoring (control) sections
3.2. Monitoring program of the East Jiu River basin
3.3. Sampling, transport and analysis of water samples
3.4. Methodology used to establish the water quality
CHAPTER 4 QUALITY ASSESSMENT OF WATER IN THE EASTERN JIU HYDROGRAPHIC BASIN
4.1. Section 1 - Jieț River - upstream of household settlements (blank assay)
4.2. Section 2 - East Jiu River - in the area of Tirici village
4.3. Section 3 - Răscoala brook - before the confluence with East Jiu River
4.4. Section 4 - East Jiu River - after the confluence with the Răscoala brook
4.5. Section 5 - Taia River - upstream of the confluence with East Jiu River
4.6. Section 6 - East Jiu River - before the confluence with the Taia River
4.7. Section 7 - East Jiu River - after the confluence with the Taia River
4.8. Section 8 - Jiet River downstream of household settlements
4.9. Section 9 - East Jiu River - after the confluence with the Jieț River
4.10. Section 10 - East Jiu River - before the confluence with Banița River
4.11. Section 11 - Roşia River - upstream of household settlements
4.12. Section 12 - Bănița River - after the confluence with the Roșia River
4.13. Section 13 - East Jiu River - after the confluence with the Banița River
4.14. Section 14 - Maleia River - before the confluence with East Jiu River
4.15. Section 15 - Slătioara River - before the confluence with East Jiu River
4.16. Section 16 – East Jiu River - before the confluence with West Jiu River
CHAPTER 5 INFLUENCES OF PHYSICAL-CHEMICAL FACTORS ON AQUATIC ICHTHYOFAUNA IN THE EAST JIU RIVER BASIN
5.1. Total suspended solids and aquatic ecosystems
5.2. Acidity or basicity reaction of surface watercourses
5.3. Aquatic ecosystem requirements for gas oversaturation
5.4. Nitrogenous compounds in watercourse
5.5. Phenols, aquatic ecosystems and water quality
CHAPTER 6 ANALYSIS OF THE IMPACT GENERATED BY ECONOMIC ACTIVITIES IN THE EASTERN PART OF JIU VALLEY
6.1. Impact analysis of mining industry in the Eastern Part of Jiu Valley
6.2. The general impact of Eastern Jiu Valley dumps to water quality
6.3. Research on effective infiltration in the Eastern part of Jiu Valley
6.4. Research on groundwater quality in the Eastern part of Jiu Valley
6.5. Analysis of the impact generated by local micro-agriculture
6.6. Analysis of the impact generated by deforestation and wood processing
6.7. Analysis of the impact generated by non-compliant landfilling of waste
CHAPTER 7 EVOLUTION OF THE IMPACT GENERATED BY ECONOMIC ACTIVITIES IN THE EASTERN JIU VALLEY
7.1. Analysis of the dynamic elements of the watercourse - RMA2 mode
7.2. Analysis of pollutants concentration evolution in the water course - RMA4 module
7.3. Computational field and composition of the energy model of the East Jiu River
7.4. Extension and evolution of the impact generated by economic activities on the East Jiu River
7.5. Extension and evolution of the impact caused by organic pollution of the East Jiu River
CHAPTER 8 MAGNITUDE AND COMPLEXITY OF THE IMPACT GENERATED
BY ECONOMIC ACTIVITIES IN THE EASTERN JIU VALLEY
8.1. Definition of input linguistic variables
8.2. Linguistic outputs of the fuzzy interference system
8.3. Defining the Black Box set of rules
8.4. Proficiency testing of complex systems based on fuzzy logic
8.5. While it is all about the wheel do not forget about the cube
CONCLUSIONS AND PERSONAL CONTRIBUTIONS
REFERENCES
|
87 |
Stratégies et techniques de pêche dans le Golfe persique au Néolithique (VI-IVe millénaires av. n.è.) : étude des assemblages ichtyologiques des sites néolithiques d'Akab, de Dalma et de Marawah MR11 (Emirats Arabes Unis) / Fishing strategies and techniques in the Persian Gulf during the Neolithic (6e-4e millenia BC) : study of the ichthyological assemblages of Akab, Dalma ans Marawah MR11 (United Arab Emirats)Lidour, Kevin 21 December 2018 (has links)
Cette thèse intègre l'analyse inédite de plus de 80 000 restes provenant des sites néolithiques d'Akab, de Dalma et de Marawah MR11 (Emirats Arabes Unis) – occupés entrela moitié du VIe et la fin du IVe millénaire av. n. è. Les résultats dévoilent des pêcheries déjà investies dans l'exploitation d'une grande variété de milieux marins. Les poissons capturés et consommés par ces pêcheurs incluent de nombreux sargues, pagres (Sparidae), empereurs (Lethrinidae) et petites aiguilles (Belonidae) qui témoignent avant tout de l'exploitation des eaux côtières peu profondes : le long des rivages ainsi que dans les zones d'herbiers et de récif frangeant. À Akab, la pêche dans la lagune et la mangrove est également reflétée par la présence de nombreux poissons‐chats marins (Ariidae) et mulets (Mugilidae) dans l'assemblage. Les techniques impliquées dans ce type de pêche sont peu sélectives et relativement simples : la prospection des petits fonds à l'aide de senne, la pose de filets calés, voire l'utilisation de barrages à poissons. À Dalma, des nasses étaient probablement déjà employées dans les zones de récifs moyennement profondes, pour la capture de mérous en particulier (Serranidae). Les mangroves et les zones de récifs sont des environnements très productifs auprès desquels les pêcheurs pouvaient vraisemblablement se fournir en poissons et en coquillages tout au long de l'année. En l'occurrence, ceux d'Akab connaissaient et exploitaient probablement déjà les grands rassemblements de becs‐decane (Lethrinus nebulosus) près de la lagune d'Umm al‐Quwain, au printemps et à l'occasion de leur frai. L'étude du matériel d'Akab et de Dalma révèle toutefois aussi l'existence d'expéditions de pêche en mer ouverte, impliquant l'usage de bateaux. Ces expéditions sont notamment conduites à la recherche des bancs de thonines (Scombridae) voire de carangues (Carangidae). Leur pêche n'impliquait pas seulement l'emploi de lignes munies d'hameçons en nacre mais aussi celui de filets tels que des sennes tournantes. Ces filets ont également permis aux pêcheurs de Dalma de capturer de grands requins et quelques dauphins plus occasionnellement. Bien que la pêche des bancs de pélagiques soit aujourd'hui considérée comme une activité hivernale dans les pêcheries du Golfe persique, l'existence d'un climat plus humide au Néolithique, alors soumis au régime de la mousson de l'Océan Indien, invite à nuancer nos modèles de saisonnalité.Au Néolithique, la pêche était ainsi pratiquée à la fois de manière généraliste et de manière spécialisée en faisant contribuer un large panel de techniques et de savoirs écologiques aux besoins d'une économie de subsistance reposant principalement sur l'exploitation des ressources marines. / This thesis presents the results of a study of more than 80,000 fish bones from the Neolithic settlement of Akab, Dalma and Marawah MR11 (United Arab Emirates) – inhabited from the mid‐6th to the end of the 4th millennia BC. The analysis has outlined that fishing was carried out in a wide range of marine habitats.The fish taxa caught and consumed by Neolithic fishermen include seabreams (Sparidae),emperors (Lethrinidae) and small needlefish (Belonidae) indicating the exploitation of coastal shallow waters : along the seashore, the beaches, over seagrass beds and fringingreefs. At Akab, the exploitation of the lagoon and the mangrove is also indicated by the occurrence of sea catfish (Ariidae) and mullets (Mugilidae) in the bone assemblage. The fishing techniques involved in such catches are non‐selective such as small seines, set nets or coastal barrier traps. At Dalma, the installation of baited cage traps in deeper reef areas isalso suggested by the importance of large groupers (Serranidae). Mangroves and reefs a reproductive marine environments which might have provided enough fish and shellfish allyear round for Neolithic coastal communities. Akab fishermen probably already knew and exploited the spawning phenomenon of the spangled emperor (Lethrinus nebulosus) in the vicinity of the Umm al‐Quwain lagoon.The exploitation of the open sea is documented as well at Akab and Dalma. Fishing expeditions in open sea however require the use of boats. Pelagic schools of kawakawas (little tuna ; Scombridae) and trevallies (Carangidae) were probably exploited not only withlines but also with fishing nets such as purse seines. At Dalma, large sharks and occasionally dolphins were also caught in this way. Despite that the fishing of pelagic schools is nowadays considered as a winter activity in the Persian Gulf, the existence of a wetter climate during Neolithic, affected by the Indian Ocean monsoon, leads us to temper our seasonal models. During the Neolithic, fishing was conducted both in non‐selective and specialised ways. Awide range of fishing techniques and ecological knowledges have contributed to the subsistence of coastal societies whose economies were primarily focused toward the exploitation of marine resources.
|
88 |
As assembléias de peixes da Zona Litoral de Lagoas Costeiras Subtropicais do Sistema do Rio Tramandaí/RS : aspectos amostrais, variações espaciais e temporais de descritores ecológicos e suas relações com a variabilidade ambientalArtioli, Luiz Guilherme Schultz January 2012 (has links)
Lagoas costeiras são ecossistemas cruciais para conservação da biodiversidade local e global. O sistema do rio Tramandaí (SRT) apresenta uma série de lagoas costeiras rasas conectadas por canais naturais, e uma saída, via estuário de Tramandaí, para o oceano. Esse sistema é dividido em dois subsistemas, ao norte e ao sul do estuário, resultado de padrões hidrodinâmicos e da influência do vento e que definem características ambientais distintas a esses subsistemas. Um gradiente decrescente, de norte a sul, no estado trófico dessas lagoas já foi verificado. No presente estudo é testada hipótese de variabilidade espacial (lagoas e subsistemas) e temporal (estações do ano) na magnitude de variáveis abióticas e de descritores ecológicos das assembleias de peixes (composição, riqueza, diversidade, dominância) do SRT. Também é avaliada a relação entre variáveis abióticas e descritores das assembleias nesses subsistemas. É comparada a seletividade de captura de um amostrador ativo (rede de arrasto de praia) e de um amostrador passivo (redes de emalhe). Amostragens foram conduzidas de novembro de 2008 a abril de 2010 com rede de arrasto de praia e redes de emalhe, na zona litoral das lagoas Itapeva, Quadros e Malvas no subsistema norte, e nas lagoas Fortaleza, Rondinha e Barros no subsistema sul. Entre abril de 2009 e março de 2010, amostras de água foram coletadas e dez variáveis foram mensuradas em laboratório. Análises de ordenação (NMDS) mostraram clara diferença de composição, abundância numérica (CPUEn) e em biomassa (CPUEb) de espécies entre amostradores. A análises de ANOSIM e SIMPER mostraram baixa similaridade desses parâmetros entre amostradores. Houve diferença no tamanho dos peixes coletados com redes de arrasto e emalhe. Turbidez e DBO5 tiveram médias superiores no subsistema norte, enquanto que condutividade, salinidade, dureza, sólidos totais dissolvidos e transparência de Secchi no subsistema sul. Temporalmente foram verificadas diferenças de temperatura, pH, salinidade, turbidez, dureza, sólidos totais dissolvidos, oxigênio dissolvido, sólidos suspensos e profundidade, mas somente os dados de pH, condutividade, turbidez e DBO5 mostraram interação entre os fatores espaço e tempo. As assembleias das margens rasas da zona litoral foram dominadas por dez espécies, resultando em alta similaridade de composição, CPUEn e CPUEb entre os subsistemas. A riqueza de espécies variou espacial e temporalmente. Diversidade e equitabilidade espacialmente, e CPUEn e CPUEb temporalmente. As assembleias das regiões pelágicas da zona litoral foram dominadas por sete espécies, com dominância numérica das espécies L. anus e A. aff. fasciatus no subsistema norte. A NMDS mostrou similaridades maiores de composição, CPUEn e CPUEb entre amostras de um mesmo subsistema, no entanto, a ANOSIM não apresentou resultados significativos para rejeição das hipóteses nulas. CPUE n e b, diversidade e equitabilidade variaram espacialmente, enquanto a riqueza, temporalmente. A análise de correlação canônica (CCA) mostrou que temperatura, DBO5, sólidos suspensos e dureza responderam por 46% da variabilidade dos dados de abundância numérica das espécies. Os resultados sugerem que amostradores ativos e passivos reproduzem diferentes imagens da assembleia por eles amostrada, indicando que o delineamento amostral para estudos com peixes nesses ecossistemas deve contemplar tais diferenças. As diferenças ambientais dos subsistemas refletem em diferenças na qualidade da água e os resultados obtidos confirmam os pressupostos do gradiente trófico. A estrutura das assembleias de peixes foi mais variável em resposta as condições ambientais em escala espacial, enquanto que temporalmente, houve maior coerência na variabilidade dos dados. As relações das espécies com as variáveis ambientais são discutidas com base no comportamento alimentar e/ou reprodutivo das mesmas e na qualidade do habitat. Tais resultados podem ser úteis como subsídio a elaboração de estudos de manejo costeiro do SRT, sobretudo com relação aos recursos pesqueiros, e na proposição de modelos de estrutura das assembleias de peixes de lagoas costeiras subtropicais. / Coastal lakes ecosystems are crucial for conserving biodiversity both locally and globally. The river Tramandaí system (SRT) comprises a series of shallow coastal lagoons, connected by natural channels, and has an output via Tramandaí estuary into the ocean. This system is divided into two subsystems, north and south of the Tramandaí estuary, as result of hydrodynamic patterns, influence of wind and environmental characteristics that define the subsystems. A trophic gradient decreasing from north to south in those lagoons was identified. In this study is tested the hypothesis of spatial (lagoons and subsystems) and temporal (seasons) variabilities in the amplitude of abiotic variables and descriptors of the fish assemblages (species composition, richness, diversity, dominance) in the SRT. It also assessed the relationship between abiotic variables and descriptors of the fish assemblages in these subsystems. Is compared the selectivity of the active fishing (beach seining) and passive (gill netting) fishing. Sampling was conducted from November 2008 to April 2010 with beach seine and gill nets in the littoral zone of lakes Itapeva, Quadros and Malvas in north subsystem, and Fortaleza, Rondinha and Barros lakes, in south subsystem. Between April 2009 and March 2010 water samples were collected and ten variables were measured in the laboratory. Analyses of ordination (NMDS) showed clear differences in composition, numerical abundance (CPUEn) and biomass (CPUEb) of species between samplers. The analysis of similarity (ANOSIM and SIMPER) showed low similarity of these parameters between nets. There was a difference in the size of the fish caught with beach seine and gill nets. Turbidity and BOD5 averages were higher in the northern subsystem, while the conductivity, salinity, hardness, total dissolved solids and Secchi transparency in the south subsystem. Temporally were observed differences in temperature, pH, salinity, turbidity, hardness, total dissolved solids, dissolved oxygen, suspended solids and depth, but only the data for pH, conductivity, turbidity, BOD5 showed interaction between the factors space and time. The assemblages of the shallow margins of the coastal zone were dominated by ten species resulting in high similarity of composition, CPUEn and CPUEb between subsystems. Species richness varied spatially and temporally, while diversity and evenness only spatially and CPUEn and CPUEb only temporally. The assemblages of the pelagic regions of the coastal zone were dominated by seven species with numerical dominance of L. anus and A. aff. fasciatus in north subsystem. The NMDS showed greatest similarity in composition, CPUEn and CPUEb between samples of the same subsystem, the ANOSIM however, showed no significant results for rejection of the null hypothesis. CPUE n and b, diversity and equitability varied between lakes and subsystems, while the richness between seasons. The canonical correlation analysis (CCA) showed that four variables (temperature, BOD, suspended solids and hardness) account for 46% of data variability of species abundance. Samples of the north subsystem were directly influenced by temperature, BOD and suspended solids while the south subsystem by the hardness. The results suggest that active and passive samplers reproduce different images of the assemblage sampled and indicate that the sampling design for studies of these ecosystems should include such differences. The environmental differences in subsystems reflect in water quality differences and the results confirm the assumptions of a trophic gradient decreasing from north to south in the SRT. The structure of the fish assemblages was more variable in response to environmental conditions in spatial scale between subsystems, while there was greater consistency in the temporal variability of the data. The relationships between the species and environmental variables are discussed based on the feeding behavior and / or reproduction of the same and by habitat quality. These results may be useful as an aid to preparing studies of coastal management of SRT, especially with respect to fisheries, and in proposing models of the structure of the fish assemblages of subtropical coastal lagoons.
|
89 |
Estrutura e variação espacial da ictiofauna em um reservatório do semiárido brasileiro / Structure and space variation of the ictiofauna in a reservoir of the Brazilian semibarrenFreire, Carlos Eduardo Campos 25 February 2013 (has links)
Made available in DSpace on 2016-08-15T20:31:13Z (GMT). No. of bitstreams: 1
CarlosECF_DISSERT.pdf: 2025658 bytes, checksum: 61bbaaabc4dd7b4dd471f25f8b53769c (MD5)
Previous issue date: 2013-02-25 / Conselho Nacional de Desenvolvimento Científico e Tecnológico / The objective of this paper was to study the spacial structure of the assembly of fish in a reservoir of the Brazilian semibarren. Quarterly collections had been made during two years, in the three regions of the reservoir Santa Cruz's Apodi, Brazilian Semiarid (lacustrine, transition and fluvial ) using gill nets and the captured individuals had been separated by species, counted and the abundance transformed into CPUE for the analyses. The wealth has been calculated estimated by the Jacknife method, index of diversity of Shannon-Winner and equitability. To evaluate the spacial distribution of the assembly we use ordinance MDS (Bray-Curtis distance). ANOSIM was applied to verify statistical differences (p<0,05) in the spacial structure of the assemblies between the regions and SIMPER was used to identify the species that contribute most for the dissimilarity in captures by region. 6,047 individuals of 20 species, 10 families and 3 orders had been captured: Characiformes, Siluriformes and Perciformes. The biggest wealth of species was estimated in the fluvial region (21.8±1.5). The biggest values of diversity (H' =2.878) and equitability (J' =0.7150) had been found in the lacustrine and transistion regions. In accordance with the analyses of MDS and ANOSIM, different assemblies had been found in the reservoir with significant difference between the fluvial region and the lacustrine and transistion regions. The Analysis SIMPER identified Moenkausia dichroura as the species that contributed the most for the difference between the regions of the reservoir. Our results had indicated that the spacial structure of the assembly of fish of the reservoir of Santa Cruz differed from Brazilian reservoirs located in other climatic regions. The intermittency characteristics of the river and the reservoir limnological aspects were the major discriminators of results for the patterns of diversity and spatial distribution of fish species found in the study / O objetivo do trabalho foi estudar a estrutura espacial da assembleia de peixes em um reservatório do semiárido brasileiro. Realizaram-se coletas trimestrais, durante dois anos (2010/2011), nas três regiões do reservatório Santa Cruz do Apodi, Semiárido brasileiro (lacustres, transição e fluvial) usando redes de espera e os indivíduos capturados foram separados por espécie, contados e a abundância transformada em CPUE para as análises. Calculou-se a riqueza estimada pelo método Jacknife, índice de diversidade de Shannon-Winner e equitabilidade. Para avaliar a distribuição espacial da assembleia usou-se a ordenação MDS (distância Bray-Curtis). Análise de Similaridade (ANOSIM) foi aplicada para verificar diferenças estatísticas (p<0,05) na estrutura espacial das assembleias entre as regiões e SIMPER foi utilizado para identificar as espécies que mais contribuem para a dissimilaridade nas capturas por região. Foram capturados 6.047 indivíduos de 20 espécies, 10 famílias e 3 ordens: Characiformes, Siluriformes e Perciformes. A maior riqueza de espécies foi estimada na região fluvial (21,8±1,5) e os maiores valores de diversidade (H =2,878) e equitabilidade (J =0,7150) foram encontrados nas regiões lacustre e transição. De acordo com as análises de MDS e ANOSIM, diferentes assembleias foram encontradas no reservatório com diferença significativa entre a região fluvial das regiões de transição e lacustre, para ambas. O teste de similaridade percentual (SIMPER) identificou Moenkausia dichroura como a espécie que mais contribuiu para a diferença entre as regiões do reservatório. Nossos resultados indicaram que a estrutura espacial da assembleia de peixes do reservatório de Santa Cruz diferiu de reservatórios brasileiros localizados em outras regiões climáticas. As características de intermitência do rio e os aspectos limnológicos do reservatório foram os principais discriminadores dos resultados encontrados para os padrões de diversidade e distribuição espacial da ictiofauna encontradas no estudo.
|
90 |
As assembléias de peixes da Zona Litoral de Lagoas Costeiras Subtropicais do Sistema do Rio Tramandaí/RS : aspectos amostrais, variações espaciais e temporais de descritores ecológicos e suas relações com a variabilidade ambientalArtioli, Luiz Guilherme Schultz January 2012 (has links)
Lagoas costeiras são ecossistemas cruciais para conservação da biodiversidade local e global. O sistema do rio Tramandaí (SRT) apresenta uma série de lagoas costeiras rasas conectadas por canais naturais, e uma saída, via estuário de Tramandaí, para o oceano. Esse sistema é dividido em dois subsistemas, ao norte e ao sul do estuário, resultado de padrões hidrodinâmicos e da influência do vento e que definem características ambientais distintas a esses subsistemas. Um gradiente decrescente, de norte a sul, no estado trófico dessas lagoas já foi verificado. No presente estudo é testada hipótese de variabilidade espacial (lagoas e subsistemas) e temporal (estações do ano) na magnitude de variáveis abióticas e de descritores ecológicos das assembleias de peixes (composição, riqueza, diversidade, dominância) do SRT. Também é avaliada a relação entre variáveis abióticas e descritores das assembleias nesses subsistemas. É comparada a seletividade de captura de um amostrador ativo (rede de arrasto de praia) e de um amostrador passivo (redes de emalhe). Amostragens foram conduzidas de novembro de 2008 a abril de 2010 com rede de arrasto de praia e redes de emalhe, na zona litoral das lagoas Itapeva, Quadros e Malvas no subsistema norte, e nas lagoas Fortaleza, Rondinha e Barros no subsistema sul. Entre abril de 2009 e março de 2010, amostras de água foram coletadas e dez variáveis foram mensuradas em laboratório. Análises de ordenação (NMDS) mostraram clara diferença de composição, abundância numérica (CPUEn) e em biomassa (CPUEb) de espécies entre amostradores. A análises de ANOSIM e SIMPER mostraram baixa similaridade desses parâmetros entre amostradores. Houve diferença no tamanho dos peixes coletados com redes de arrasto e emalhe. Turbidez e DBO5 tiveram médias superiores no subsistema norte, enquanto que condutividade, salinidade, dureza, sólidos totais dissolvidos e transparência de Secchi no subsistema sul. Temporalmente foram verificadas diferenças de temperatura, pH, salinidade, turbidez, dureza, sólidos totais dissolvidos, oxigênio dissolvido, sólidos suspensos e profundidade, mas somente os dados de pH, condutividade, turbidez e DBO5 mostraram interação entre os fatores espaço e tempo. As assembleias das margens rasas da zona litoral foram dominadas por dez espécies, resultando em alta similaridade de composição, CPUEn e CPUEb entre os subsistemas. A riqueza de espécies variou espacial e temporalmente. Diversidade e equitabilidade espacialmente, e CPUEn e CPUEb temporalmente. As assembleias das regiões pelágicas da zona litoral foram dominadas por sete espécies, com dominância numérica das espécies L. anus e A. aff. fasciatus no subsistema norte. A NMDS mostrou similaridades maiores de composição, CPUEn e CPUEb entre amostras de um mesmo subsistema, no entanto, a ANOSIM não apresentou resultados significativos para rejeição das hipóteses nulas. CPUE n e b, diversidade e equitabilidade variaram espacialmente, enquanto a riqueza, temporalmente. A análise de correlação canônica (CCA) mostrou que temperatura, DBO5, sólidos suspensos e dureza responderam por 46% da variabilidade dos dados de abundância numérica das espécies. Os resultados sugerem que amostradores ativos e passivos reproduzem diferentes imagens da assembleia por eles amostrada, indicando que o delineamento amostral para estudos com peixes nesses ecossistemas deve contemplar tais diferenças. As diferenças ambientais dos subsistemas refletem em diferenças na qualidade da água e os resultados obtidos confirmam os pressupostos do gradiente trófico. A estrutura das assembleias de peixes foi mais variável em resposta as condições ambientais em escala espacial, enquanto que temporalmente, houve maior coerência na variabilidade dos dados. As relações das espécies com as variáveis ambientais são discutidas com base no comportamento alimentar e/ou reprodutivo das mesmas e na qualidade do habitat. Tais resultados podem ser úteis como subsídio a elaboração de estudos de manejo costeiro do SRT, sobretudo com relação aos recursos pesqueiros, e na proposição de modelos de estrutura das assembleias de peixes de lagoas costeiras subtropicais. / Coastal lakes ecosystems are crucial for conserving biodiversity both locally and globally. The river Tramandaí system (SRT) comprises a series of shallow coastal lagoons, connected by natural channels, and has an output via Tramandaí estuary into the ocean. This system is divided into two subsystems, north and south of the Tramandaí estuary, as result of hydrodynamic patterns, influence of wind and environmental characteristics that define the subsystems. A trophic gradient decreasing from north to south in those lagoons was identified. In this study is tested the hypothesis of spatial (lagoons and subsystems) and temporal (seasons) variabilities in the amplitude of abiotic variables and descriptors of the fish assemblages (species composition, richness, diversity, dominance) in the SRT. It also assessed the relationship between abiotic variables and descriptors of the fish assemblages in these subsystems. Is compared the selectivity of the active fishing (beach seining) and passive (gill netting) fishing. Sampling was conducted from November 2008 to April 2010 with beach seine and gill nets in the littoral zone of lakes Itapeva, Quadros and Malvas in north subsystem, and Fortaleza, Rondinha and Barros lakes, in south subsystem. Between April 2009 and March 2010 water samples were collected and ten variables were measured in the laboratory. Analyses of ordination (NMDS) showed clear differences in composition, numerical abundance (CPUEn) and biomass (CPUEb) of species between samplers. The analysis of similarity (ANOSIM and SIMPER) showed low similarity of these parameters between nets. There was a difference in the size of the fish caught with beach seine and gill nets. Turbidity and BOD5 averages were higher in the northern subsystem, while the conductivity, salinity, hardness, total dissolved solids and Secchi transparency in the south subsystem. Temporally were observed differences in temperature, pH, salinity, turbidity, hardness, total dissolved solids, dissolved oxygen, suspended solids and depth, but only the data for pH, conductivity, turbidity, BOD5 showed interaction between the factors space and time. The assemblages of the shallow margins of the coastal zone were dominated by ten species resulting in high similarity of composition, CPUEn and CPUEb between subsystems. Species richness varied spatially and temporally, while diversity and evenness only spatially and CPUEn and CPUEb only temporally. The assemblages of the pelagic regions of the coastal zone were dominated by seven species with numerical dominance of L. anus and A. aff. fasciatus in north subsystem. The NMDS showed greatest similarity in composition, CPUEn and CPUEb between samples of the same subsystem, the ANOSIM however, showed no significant results for rejection of the null hypothesis. CPUE n and b, diversity and equitability varied between lakes and subsystems, while the richness between seasons. The canonical correlation analysis (CCA) showed that four variables (temperature, BOD, suspended solids and hardness) account for 46% of data variability of species abundance. Samples of the north subsystem were directly influenced by temperature, BOD and suspended solids while the south subsystem by the hardness. The results suggest that active and passive samplers reproduce different images of the assemblage sampled and indicate that the sampling design for studies of these ecosystems should include such differences. The environmental differences in subsystems reflect in water quality differences and the results confirm the assumptions of a trophic gradient decreasing from north to south in the SRT. The structure of the fish assemblages was more variable in response to environmental conditions in spatial scale between subsystems, while there was greater consistency in the temporal variability of the data. The relationships between the species and environmental variables are discussed based on the feeding behavior and / or reproduction of the same and by habitat quality. These results may be useful as an aid to preparing studies of coastal management of SRT, especially with respect to fisheries, and in proposing models of the structure of the fish assemblages of subtropical coastal lagoons.
|
Page generated in 0.0494 seconds