Orientador: Jorge Laço Portinho / Resumo: O objetivo deste estudo foi conhecer a distribuição de Cladocera na zona litorânea de lagoas marginais, abrangendo a comunidade de forma completa, incluindo suas formas ativa e dormente, encontradas nos habitats que compõem essa região: coluna d’água, sedimento e banco de macrófitas. O estudo foi realizado em quatro lagoas marginais. Em cada lagoa foram definidas quatro estações de amostragem, em cada estação foram amostrados os três habitats, sedimento e macrófita (comunidade dormente), e coluna d’água abaixo das macrófitas (comunidade ativa). Ao investigar essa organização, observamos que a comunidade de Cladocera se distribui de forma heterogênea entre os três habitats. O banco de ovos no sedimento apresenta maior riqueza de espécies e maior número de ovos, quando comparado ao banco de ovos nas macrófitas. A comunidade ativa e os bancos de ovos apresentam elevada interação em relação à deposição e eclosão de ovos. O sedimento e a coluna d’água são os principais habitats onde as espécies se distribuem, e embora apresentem elevada similaridade entre si (táxons em comum), esses habitats isoladamente não são capazes de representar de forma completa a composição e riqueza da comunidade de Cladocera da região litorânea, pois cada um apresenta táxons de ocorrência exclusiva. / Abstract: The objective of this study was to know the distribution of Cladocera in littoral area of marginal lagoons, covering the community completely, including its active and dormant forms found in the habitats that make up this area: macrophytes bank, sediment and water column. The study was carried out in four marginal lakes. In each lake four sampling stations were defined, in each station the three habitats were sampled, sediment and macrophyte (dormant egg banks), and water column below the macrophytes (active community). In investigating this organization, we observed that the community of Cladocera is distributed heterogeneously among the three habitats. The egg bank in the sediment presents higher species richness and higher egg numbers when compared to egg banks in macrophytes. The active community and the egg banks present high interaction in relation to resting eggs deposition and hatching. The sediment and the water column are the main habitats where the species are distributed, and although they have a high similarity between them (common taxa), these habitats alone are not able to fully represent the composition and richness of the community of Cladocera in littoral area, since each one presents taxa of exclusive occurrence. / Mestre

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No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) PDF - Gustavo Correia de Moura.pdf: 4048269 bytes, checksum: 93440f590dbf6da5c94a68be759a0082 (MD5) Previous issue date: 2015-08-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This study aimed to analyze the drivers factors of biomass, functional diversity and fatty acids of the zooplankton community in two tropical estuaries with different trophic states (Mamanguape and Paraíba do Norte), located in Northeastern Brazil. The study was divided into two manuscripts which were sampled in dry and rainy season, as follows: Nov/2013 to Jul/2014, for the first manuscript and Dec/2014 and Jul/2014 to the second manuscript, respectively. Four sample zones were selected along each estuary and in each one were selected three sites where at each site three biotic samples (zooplankton community) and abiotic (environmental variables) were sampled. The fatty acid profiles were obtained from gas chromatography techniques from selected copepod species. In the first study, we tested whether the estuarine connectivity, the phylogenetic relationships and the local environmental conditions are the main drivers of the pattern of distribution of biomass and functional diversity of the zooplankton community. It was observed that these three components are sufficient to explain the variation in Mamanguape estuary that is located in a conservation area, and different than is commonly expected, the connectivity can provide greater explicability for the community distribution, when compared to the environmental conditions. However, the three components used were not sufficient to explain the variation in Paraíba do Norte estuary which is influenced by anthropogenic impacts. The study shows the importance of spatial variable to assess the drivers factors of biomass and functional diversity of the zooplankton community, as this part of the analysis the effects of dispersal ability of species and the physical forces acting on the system. Moreover, a thorough investigation is needed to clarify the factors that determine and shape the zooplankton communities in high impacted tropical systems. In the second study, we tested whether the profiles of fatty acids can reveal spatial and temporal changes in diet of copepods, and therefore can be used as indicators of the trophic status of estuaries. It was observed that the fatty acid composition of zooplanktonic organisms revealed seasonal and temporal variations in trophic ecology of copepods in both tropical estuaries. In addition, the profiles of fatty acids were able to reveal differences in the quality of potential food sources in the two estuaries with different levels of anthropogenic impact, with a lower quality of food sources in the most impacted system (Paraíba do Norte estuary). In this study the profiles of fatty acids were sensitive to natural and anthropogenic stresses, being a fast tool to assess the trophic status of tropical estuaries. / O presente estudo teve por objetivo analisar os fatores direcionadores da biomassa, diversidade funcional e ácidos graxos da comunidade zooplanctônica em dois estuários tropicais com diferentes estados tróficos (Mamanguape e Paraíba do Norte), localizados no Nordeste do Brasil. O estudo foi dividido em dois manuscritos os quais tiveram amostragens realizadas no período de seca e cheia, sendo: nov/2013 e jul/2014, para o primeiro manuscrito e dez/2014 e jul/2014 para o segundo manuscrito, respectivamente. Foram selecionados quatro zonas amostrais ao longo de cada estuário e em cada uma foram selecionados três pontos onde em cada ponto três amostras bióticas (comunidade zooplanctônica) e abióticas (variáveis ambientais) foram coletadas. Os perfis de ácidos graxos foram obtidos à partir de técnicas de cromatografia gasosa das espécies de copépodes selecionados. No primeiro estudo, foi testado se a conectividade estuarina, as relações filogenéticas e as condições ambientais locais são os principais direcionadores do padrão de distribuição da biomassa e diversidade funcional da comunidade zooplanctônica. Observou-se que esses três componentes são suficientes para explicar a variação no estuário Mamanguape que se localiza em uma área de conservação, e que diferente do que é comumente esperado, a conectividade pode apresentar uma explicabilidade maior na distribuição da comunidade, quando comparada às condições ambientais. No entanto, os três componentes utilizados não foram suficientes para explicar a variação no estuário Paraíba do Norte o qual sofre a influência de impactos antrópicos. O estudo mostra a importância da variável espacial para avaliar os fatores direcionadores da biomassa e diversidade funcional da comunidade zooplanctônica, visto que esta integra à análise os efeitos da capacidade de dispersão das espécies e das forças físicas que atuam no sistema. Além disso, uma investigação aprofundada é necessária para esclarecer os fatores que determinam e moldam as comunidades zooplanctônicas em sistemas tropicais muito impactados. No segundo estudo, foi testado se os perfis de ácidos graxos podem revelar mudanças espaciais e temporais na dieta de copépodos, e por conseguinte, possam ser usados como indicadores do estado trófico dos sistemas estuarinos. Foi possível observar que a composição de ácidos gráxos dos organismo zooplanctônicos revelaram variações sazonais e temporal na ecologia trófica dos copépodos nos dois estuários tropicais. Além disso, os perfis de ácidos gráxos foram capazes de revelar diferenças na qualidade das potenciais fontes de alimento nos dois estuários com diferentes níveis de impacto antrópico, com uma menor qualidade de fontes alimentares presente no sistema mais impactado (estuário do Paraíba do Norte). Nesse estudo os perfis de ácidos gráxos foram sensíveis à estresses naturais e antrópicos, mostrando ser uma ferramenta rápida para avaliar o estado trófico de estuários tropicais.

A represa de Piracuruca está localizada no município de Piracuruca, a 3º58\'S e 41º40\'W, na região Norte do Estado do Piauí. A vegetação do entorno é do tipo cerrado, com solos ácidos e pobres em nutrientes. O seu uso é caracterizado pela pecuária extensiva e agricultura de subsistência. O presente estudo visa a caracterização da represa de Piracuruca considerando os fatores físicos e químicos da água e a comunidade zooplanctônica. As características físicas e químicas de um ambiente aquático são fundamentais para o conhecimento de seu funcionamento. Em termos de oxigenação da água, o epilímnio apresentou valores relativamente altos de oxigênio dissolvido e anoxia no hipolímnio, tanto em escala sazonal como interanual. Para a temperatura foram observadas pequenas amplitudes de variação e formação de termoclinas nas camadas superiores de epilímnio. Devido às características arenosas dos solos e a decomposição da matéria orgânica na represa, os materiais suspensos foram predominantemente caracterizados pela função inorgânica, nos períodos amostrados. As altas concentrações de fósforo, derivadas principalmente da decomposição da vegetação submersa não removida durante a fase de enchimento do reservatório, ocasionaram um elevado grau de trofia para o ecossistema. O zooplâncton foi composto por vinte e nove táxons de Rotifera, nove de Cladocera e três de Copepoda, não havendo diferenças significativas na composição dos táxons encontrados na região\"litorânea\" e na região limnética. Para o zooplâncton foi registrado um índice de diversidade relativamente alto, não ocorrendo, no entanto, as diferenças sazonais significativas em termos de abundância ou composição taxonômica. / Piracuruca reservoir is located on Piracuruca municipality at 3°58\'S and 41°40\'W in the region North of Piauí State. The surrounding vegetation is a savannah type called \"cerrado\", with acid soils, poor in nutrients. Landuse is characterized by extensive cattling and subsistence agriculture. The present work intends to do a limnological characterisation of Piracuruca reservoir, considering physical and chemical water factors and zooplanktonic community. Physical and chemical features of a water body are environment are important for its functioning understanding. Regarding water oxygenation, epiliminion had high dissolved oxygen content and anoxia acurred in the hypolimion, and interanual and seasonal scale. For temperature it was observed a small variation amplitude and thermocline formation in epiliminion superior layers. Due to soils sandy features the suspended matter was predominantly characterised by the inorganic fraction, in both periods. High phosphorus concentrations, originated mainly from decomposition of the submersed vegetation, not removed during the reservoir filling phase, caused a high trophy degree for the ecosystem. Zooplankton was composed by twenty-nine Rotifera taxa, nine Cladocera taxa and three Copepoda taxa; there were no significant differences among the taxa composition in littoral and limnetic region. Diversity indices for zooplankton community were relatively high and there were no relevant seasonal differences registered in abundance or taxonomic composition.

This research focused on population dynamics of two gelatinous zooplankters (Aequorea & Pyrosoma atlanticum) in the northern California Current to assess their relationship to environmental conditions and role in the pelagic ecosystem. Data collected since 1999 showed seasonal and interannual fluctuations in the abundance and distribution of Aequorea in the NCC, with a positive correlation with sea surface temperature and salinity. Pyrosoma atlanticum, which are typically found in tropical waters, have only been observed in high abundances in the NCC since 2014 and their role in the pelagic ecosystem is not well understood. Pyrosome abundance related to in situ environmental variables showed a positive correlation with warmer SST. We also used fatty acids as trophic markers to better understand pyrosome trophic ecology in the NCC. FA biomarkers suggest that pyrosomes have a broad phytoplankton diet, which may indicate an ability to inhabit warmer, lower nutrient zones. / 2020-01-11

Understanding the processes controlling the distribution and abundance of zooplankton has been a primary concern of oceanographers and has driven the development of numerous technologies to more accurately quantify these parameters. This study investigates the potential of a new plankton imaging sensor, the shadowed image particle profiling and evaluation recorder (SIPPER), that I helped develop at the University of South Florida, to address that concern. In the first chapter, results from the SIPPER are compared against concurrently sampling plankton nets and the optical plankton counter (OPC), the most widely used optical zooplankton sampling sensor in the field. It was found that plankton nets and the SIPPER sampled robust and hard-bodied zooplankton taxa similarly while nets significantly underestimated the abundance of fragile and gelatinous taxa imaged by the SIPPER such that nets might underestimate zooplankton biomass by greater than 50%. Similarly, it was determined that the OPC misses greater than a quarter of resolvable particles due to coincident counting and that it can not distinguish between zooplankton and other abundant suspended particles such as marine snow and Trichodesmium that are difficult to quantify with traditional sampling methods. Therefore the standard method of using net samples to ground truth OPC data should be reevaluated. In the second chapter, a new automated plankton classification system was utilized to see if it was possible to use machine learning methods to classify SIPPER-imaged plankton from a diverse subtropical assemblage on the West Florida Shelf and describe their distribution during a 24 hour period. Classification accuracy for this study was similar to that of other studies in less diverse environments and similar to what could be expected by a human expert for a complex dataset. Fragile plankton taxa such as larvaceans, hydromedusae, sarcodine protoctists and Trichodesmium were found at significantly higher concentrations than previously reported in the region and thus could play more important roles in WFS plankton dynamics. Most observed plankton classes were found to be randomly distributed at the fine scale (mm-100 m) and that greatest variability within plankton abundances would be encountered vertically rather than horizontally through the water column.

Bear Lake, a large oligotrophic lake (282 km2), was studied from October 1986 to December 1987 to determine the temporal changes in the zooplankton assemblage at one site in the pelagic zone and one in the littoral area. In this study, species composition, abundance, biomass, and size frequency distribution were determined. Additionally, chlorophyll a, water transparency, and temperature and oxygen profiles were measured to help interpret zooplankton changes during the study. The zooplankton species assemblage comprised eight species of cladocera, seven species of copepods, and five species of rotifers. The abundance and biomass of the zooplankton assemblage, particularly that of crustaceans, were very low and comparable with those of oligotrophic systems. Mean densities of crustaceans in the pelagic zone, excluding copepod nauplii, varied from 250 to 1,700 organisms/m3. The analysis of the size structure of the zooplankton indicated the dominance of small organisms and the scarcity of large organisms, particularly cladocera. The zooplankton assemblage in the littoral zone was similar in species composition, abundance, and size structure to that in the pelagic zone. Many results suggest the littoral zooplankton assemblage is an extension of the pelagic assemblage. Low zooplankton food resources and interference of calcium carbonate particles in the feeding behavior of crustaceans are suggested as the primary factors controlling the low abundance and biomass of zooplankton in Bear Lake. Size-selective fish predation probably causes the assemblage to be dominated by small species. The analysis of Epischura nevadensis, the dominant species in the system, indicated that this species is bivoltine in Bear Lake. In the spring and summer, adult E. nevadensis were more abundant in the littoral zone, whereas copepodites were more abundant offshore. The low density, biomass, and small size structure of the zooplankton in Bear Lake limits its importance as a source of food for fishes.

The distribution, abundance, chemical composition, metabolism, and feeding ecology of the tentaculate ctenophore, Callianira antarctica (Chun 1897), were investigated during austral winter 2001and autumn & winter 2002, in the vicinity of Marguerite Bay west of the Antarctic Peninsula. Callianira antarctica had a widespread distribution during autumn and winter, and variable abundance (0.02 to 2.6 ind. m-2) during winter 2001 associated with specific circulation features. Size frequency distributions for autumn and winter suggest that more than half of the C. antarctica population may have experienced 'degrowth' during winter due to low food availability. Callianira antarctica is a fairly robust ctenophore with geometric mean (geomean) carbon (C) and nitrogen (N) values of 8.41 and 1.83% dry weight (DW), respectively. Winter oxygen consumption and ammonium excretion rates ranged from 0.059 to 0.410 micro l O2 [mg DW]-1 h-1 and 0.60 to 31.1 µg-at N [g DW]-1 h-1, respectively, at 0oC. Daily minimum maintenance rations based on respiration experiments were 2.7% to 3.6% of the total body carbon (TBC) for small ctenophores, and 1.4% to 1.9% TBC for larger ctenophores. Calanoid copepods and larval and juvenile Antarctic krill were offered to ctenophores in incubation experiments. Digestion times were variable, lasting 8 to 20 h, and were independent of ctenophore size and dependent on number and type of prey. Gut content analysis from one autumn and two winter seasons indicated C. antarctica preyed on both copepods and krill in situ, with an increased dependence on larval krill during winter. Lipid biomarker analysis on C. antarctica and their potential prey confirmed these results. Divers observed aggregations of C. antarctica passively drifting with tentacles extended near dense concentrations of larval Euphausia superba during winter. These observations along with gut content and lipid biomarker analysis suggest that larval krill is an important prey item for C. antarctica during winter.

No description available.

Waste Stabilisation Ponds (WSPs) are a relatively simplistic and non-intensive wastewater treatment technology; with various WSP configurations widely employed to treat a range of different wastewaters the world over. Whilst the advantages of WSP treatment are both numerous and well recognized, performance problems relating to the presence of occasionally large and unpredictable quantities of plankton (both algal and zooplankton) biomass in the final pond effluents have posed significant operational problems for WSP operators; with this suspended biomass representing the single biggest drawback associated with the technology. Research conducted during this project was concerned with assessing a selection of so-called ‘advanced’ in-pond treatment processes for the upgrading or polishing of a final WSP effluent. The particular research emphasis was on the removal of problematic algal and zooplankton biomass from WSP effluent prior to Dissolved Air Flotation/Filtration (DAF/F) treatment and wastewater reuse at the Bolivar Wastewater Treatment Plant (WWTP) north of Adelaide. The in situ WSP upgrade systems assessed in this thesis were: the native floating plant ‘Duckweed’ (DW); ‘Rock Filters’ (RFs); and an artificial ‘Attached-Growth Media’ (AGM); all of which were assessed for their relative treatment efficacies parallel to a non-interventional ‘Open Pond’ (OP) system which served as an effective control. These performance comparisons were assessed on a pilot-scale using a custom made pilot treatment plant which was located at the Bolivar WWTP. Performance monitoring was periodically carried out over a 12 month period from July 2005–August 2006, with algal and zooplankton populations monitored in addition to the more conventional wastewater quality parameters. Results from pilot plant investigations demonstrated that of the four pilot upgrade series, the RF and AGM systems displayed the greatest treatment potential in terms of both the magnitude and reliability of suspended solids, algal and zooplankton biomass removals. The DW system was also shown to be at least as effective and in some instances significantly more advanced than the uncovered OP system in terms of its ability to significantly improve the final effluent quality of the Bolivar WSPs. Both the RF and AGM upgrades (and to a lesser degree also the DW system) were found to offer considerable potential for producing a higher quality WSP effluent for more efficient processing by the Bolivar DAF/F plant; although there were various operational advantages and disadvantages as well as varying capital establishment costs associated with each of the candidate technologies. This part of the research represented the first direct performance comparison between two popular pond upgrade technologies (i.e. RFs and DW) and also constituted the first assessment of a novel AGM for the upgrading of tertiary-level WSP effluent. In addition to this, results from ecological performance monitoring also provided the first detailed insights into algal and zooplankton population dynamics within these WSP upgrade environments. In addition to these pilot-scale WSP upgrade performance investigations, another branch of the research project investigated additional research questions regarding the survival of algal cells within these pond upgrade environments. A series of laboratory experiments attempted to recreate the in situ conditions (in terms of light and oxygen availability) that might exist within the adopted upgrade environments. Using two common WSP algal species, long-term monitoring of the physiological status of phytoplankton cells during prolonged dark-exposure under conditions of reduced oxygen availability was performed in order to assess the likely effects of these particular environmental conditions on their survival potential in situ. Results from these laboratory-based experiments showed that both algal species were capable of quickly adjusting their cellular metabolism in response to dark incubation. Results also showed that a reduced environmental oxygen concentration (25% of saturation) had no bearing on the ability of either Chlorella or Chlamydomonas species to withstand long-term dark-exposure; with both species retaining what was essentially full biological viability following up to two months of continuous dark-exposure. In an applied context, these results suggested that subjecting algal cells to conditions of simultaneous darkness and reduced oxygen availability would be expected to have no significant adverse effects on algal survivorship within an advanced in-pond upgrade system such as a duckweed-covered WSP, a rock filter or an AGM system.

The assemblage composition, biomass and dynamics of zooplankton and epibenthos were examined in a commercial prawn pond in southeast Queensland over two seasons. Physico-chemical characteristics of the pond water were measured concurrently. Numbers and biomass of zooplankton in the surface tows (140 micrometre mesh) varied from 8 ind. L-1 (44 micrograms L-1) to 112 ind. L-1 (324 micrograms L-1) in the first season, with peaks in biomass corresponding to peaks in numbers. In the second season the zooplankton numbers varied from 12 to 590 ind. L-1, but peaks in numbers did not correspond with peaks in biomass, which varied from 28 to 465 micrograms L-1. This was due to differences in the size of the dominant taxa across the season. Although this occurred in both seasons, the effect on biomass was more pronounced in the second season. In both seasons, immediately after the ponds were stocked with prawn postlarvae there was a rapid decline in zooplankton numbers, particularly of the dominant larger copepods. This was probably due to predation by the postlarvae. Subsequent peaks in zooplankton numbers were principally due to barnacle nauplii. The largest peaks in zooplankton numbers occurred before stocking in the first season, but the largest peaks were in the middle of the second season. While changes in abundance and biomass of the zooplankton assemblage were not correlated with physico-chemical characteristics in the first season, there were correlations between zooplankton numbers and temperature, dissolved oxygen, pH and secchi disk readings in the second season. No correlations were found with zooplankton biomass and physico-chemical characteristics in the second season. The correlations in the second season were mainly due to the high prevalence of barnacle nauplii through the middle part of the season, and may reflect suitable conditions for barnacle reproduction. Epibenthic faunal abundance in the beam trawls (1 mm mesh) peaked at 14 ind. m-2 and 7 ind. m-2 in the first and second seasons respectively and the biomasses at 0.8 g m-2 and 0.7 g m-2. Peaks in abundance of epibenthos did not correspond to peaks in biomass. This was due to large differences in the size of the taxa across the seasons. Sergestids (Acetes sibogae) and amphipods were the most abundant taxa in beam trawl samples. Amphipods were only abundant in the first season, with their numbers increasing towards the end of the grow out period. Acetes were abundant in both seasons, but were dominant in the second season. Correlations between physico-chemical parameters and epibenthos numbers were found to be strongly influenced by the dominant taxa in each season. In the first season, negative correlations were found between epibenthos abundance and pH and temperature. These relationships may reflect an effect on the growth of macroalgae in the pond, with which the amphipods were strongly associated, rather than a direct effect on the epibenthos. In the second season, a positive correlation existed between temperature and epibenthos abundance, however this was strongly influenced by the very high abundance of Acetes in the last sampling period. No correlations were found between epibenthic fauna biomass and physico-chemical parameters. Abundances of epibenthic fauna were not related to zooplankton densities indicating this source of food was not likely to be a limiting factor. Neither the pond water exchange regime nor moon phase could explain changes observed in abundances of zooplankton or epibenthos assemblages in the first season, however the sampling regime was not designed to specifically investigate these effects. In the second season water exchanges were sampled more rigorously. The density of zooplankton in the outlet water was from 2 to 59% of the density of zooplankton in the pond, and the zooplankton density of the inlet water was from 9 to 50% of the outlet water. The number of zooplankton recruited into the pond from the inlet water, after the prawns were stocked, was negligible and contributed little to changes observed in zooplankton assemblages. Reproduction of barnacles within the pond appeared to play the most important role in changes in the assemblage. Water exchange did, however, appear to play a greater role in the changes observed in epibenthic fauna assemblages. In the last season of sampling the feeding of the dominant epibenthic species, Acetes sibogae, was examined using a combination of gut content and stable isotope analysis. Acetes gained little nutrition directly from the pelleted feed, probably relying primarily on zooplankton as their direct food source. Other dietary items such as macroalgae also played a role in the nutrition of the Acetes. If Acetes numbers were high at the beginning of a season they may compete with the newly stocked prawns for the zooplankton resource. However, they will not compete with the prawns later in the season when the prawns are gaining most of their nutrition from the pelleted feed. Overall it appears that zooplankton are important to the nutrition of the prawns at the beginning of the season when the assemblage is usually dominated by copepods. Later in the season the assemblage is dominated by barnacle nauplii which are recruited from within the pond. The establishment of an abundant assemblage of suitable zooplankton species before stocking prawn postlarvae would appear to be beneficial, if not essential. The assemblage of epibenthic fauna changes throughout the season as new recruits are brought in from outside the pond. Epibenthic faunal assemblages in ponds from southeast Queensland are dominated by Acetes which are not likely to adversely affect the production of prawns unless they are particularly abundant early in the grow out season when the prawns would be utilising the same food resources as Acetes.