Thesis (Ph. D.)--Rhodes University, 2004. / Title from PDF t.p. (viewed on May 5, 2006). Includes bibliographical references (p. 145-163).

Orientador : Walter A. Boeger / Co-orientador: Frederico P. Brandini / Tese (doutorado) - Universidade Federal do Paraná, Setor de Ciencias Biológicas, Programa de Pós-Graduaçao em Zoologia. Defesa: Curitiba,18/04/ 2006 / Inclui bibliografia / Área de concentraçao: Zoologia / Limnoperna fortunei é um molusco bivalve de água doce, originário do Sudeste Asiático. Sua ocorrência na América do Sul foi relatada pela primeira vez em 1991, no estuário do Rio da Prata, Argentina. Em pouco tempo esse organismo, conhecido vulgarmente como mexilhão dourado, se dispersou por várias outras bacias hidrográficas da Argentina, Brasil, Paraguai, Bolívia e Uruguai, causando grandes prejuízos ambientais e econômicos. Outros exemplos de invasões por moluscos bivalves como o mexilhão zebra, Dreissena polymorpha, nos EUA, evidenciam a grande capacidade desses organismos em se adaptar a novos ambientes, sendo a atividade humana, provavelmente, a maior responsável pela dispersão dessas espécies. Um melhor entendimento do comportamento e dos processos dispersivos envolvidos com sua introdução possibilitam a adoção de medidas preventivas. A implementação de uma barreira definitiva ao avanço desses organismos é muito difícil, mas trabalhos de prevenção bem fundamentados podem levar a uma redução na velocidade de disseminação, o que representa uma economia de recursos financeiros e um tempo valioso para realização de pesquisas com a biologia e possíveis métodos de controle dessas espécies. O presente trabalho tem como objetivos analisar os fatores envolvidos com a disseminação de L. fortunei para novos ambientes, identificando os vetores envolvidos em sua dispersão, monitorando o avanço dessa espécie no Estado do Paraná, criando subsídios para o desenvolvimento de medidas de prevenção da disseminação desse organismo e, por meio de Sistema de Informações Geográficas, desenvolvendo uma metodologia de análise de risco de bioinvasão de bacias hidrográficas usando como modelo a bacia do rio Iguaçu. Para isso, foi realizado durante o segundo semestre de 2003, uma prospecção inicial em 10 reservatórios da Companhia Paranaense de Energia (Copel) para identificação de pontos com a presença do molusco no Estado do Paraná, sendo que o mesmo não foi encontrado no interior do Estado. A partir desse trabalho, desenvolveu-se uma metodologia de prospecção específica para o mexilhão e em 2004, 17 reservatórios da Copel passaram a ser monitorados, sendo três mensalmente e os demais trimestralmente. Trabalhos de campo foram realizados com o objetivo de identificar vetores de disseminação. Foram selecionados como principais vetores para a região o transporte de embarcações de lazer, o transporte de areia e o transporte de peixes vivos. O perfil de cada uma destas atividades foi analisado em três reservatórios de água ao longo do rio Iguaçu: Reservatório do Irai (Coordenadas planas UTM SAD69 7186592,401 S / 689794,542 W); Reservatório de Foz do Areia (7123268,672 S / 432655,958 W) e Reservatório de Salto Caxias (7172484,086 S / 248103,889 W). A equação de Von Bertalanffy foi utilizada para avaliar o crescimento populacional da espécie no lago de Itaipu, rio Paraná (7180836,029 S / 142896,969 W). Todos os dados coletados foram inseridos em um banco de dados do software Arc/View 9,0 e foram usados para gerar mapas temáticos dessas atividades. O cruzamento dessas informações em mapas georreferenciados indicou áreas com maior risco de bioinvasão pelo molusco. O modelo de análise de risco poderá ser utilizado para outras bacias hidrográficas ou conjuntos de bacias hidrográficas de uma Região, Estado ou Pais, reepresentando uma ferramenta importante no combate a este organismo invasor. Os reservatórios do rio Iguaçu estudados, apresentaram riscos variando entre médio e médio alto, o que significa que esta bacia hidrográfica pode ser contaminada pelo molusco e medidas preventivas devem ser adotadas / Limnoperna fortunei is a freshwater bivalve mollusk, original from the Southeast Asian. Its occurrence in South America was recorded for the first time in 1991, in the estuary of Rio de La Plata, Argentina. In ashort period of time, this organism, commonly known as golden mussel, it dispersed into several other hydrografic basins of Argentina, Brazil, Paraguay, and Uruguay, causing great environmental and economical damages. Other examples of invasions of bivalve mollusks is the zebra mussel, Dreissena polymorpha, in the USA, evidencing the great capacity of these organisms in adapting to new environments, being the human activity, probably, the largest responsible for its dispersion. A better understanding of the dispersion processes involved with its introduction potential make possible the adoption of preventive measures. The implementation of a definitive barrier to the progress of those organisms is very difficult, but prevention can reduce the speed of spreading, probably representing an enormous economy of resources and a valuable time for accomplishment of research on its biology and of possible methods of control. The present work has as objective to analyze the factors involved with the spread of L. fortunei into new environments, identifying the vectors involved in its dispersion, monitoring its progress the waterways of the State of Paraná, creating subsidies for the development of measures of prevention of the dispersion, through the use of Geographical Information System, developing a methodology of analysis of risk of bioinvasion of hydrographic basins, using as model the basin of the river Iguaçu. For that, during the second semester of 2003, a first search in 10 reservoirs of the Companhia Paranaense de Energia (Copel) were prospected for this mollusk species in the State of Paraná, it was not capable to detect its presence in the internal rivers systems of the state. Based on these results, a methodology of specific prospection for the mussel was applied, in 2004, in 17 reservoirs of Copel was monitored, three monthly and the remaing quarterly. Field works were also performed with the objective of identifying possible dispersion vectors. Three main vectors were identifiec as potential vectors: the transport of leisure boats, the transport of sand, and the transport of living fish. The profile of each one of these activities was analyzed in three reservoirs of water along the Rio Iguaçu: Irai Reservoir (UTM SAD69 7186592,401 S / 689794,542 W); Foz do Areia Reservoir (7123268,672 S / xiii 432655,958 W) and Salto Caxias Reservoir (7172484,086 S / 248103,889 W). Von Bertalanffy's equation was used to evaluate the population growth of the species in the Lake Itaipu, Rio Paraná (7180836,029 S / 142896,969 W). All the collected data were inserted into a database of the software Arc/View 9,0 and was used to generate thematic maps of those activities. The crossing of this information in georeferenced maps indicated areas with higher risk of bioinvasion by the mollusk. The model of risk analysis can be used in other hydrographic basins or groups of basins in an Area, State or Country, representing an important tool in the combat to this invasive organism. The reservoir analised within the Rio Iguassu presented risk values that varied betweem average to average-high, suggesting that the basin may be contaminated by the mollusk and preventing measures need to be adopted.

Orientador : Prof. Dr. Walter Antônio Pereira Boerger / Dissertação (mestrado) - Universidade Federal do Paraná, Setor de Ciências Biológicas, Programa de Pós-Graduação em Zoologia. Defesa: Curitiba, 24/07/2014 / Inclui referências / Area de concentração: Zoologia / Resumo: As invasões biológicas têm sido reconhecidas como uma das ameaças de alto impacto aos ecossistemas naturais. Os ambientes mais susceptíveis à introdução acidental de espécies são regiões estuarinas e lagos, pois muitas das espécies exóticas e potencialmente invasoras são organismos aquáticos. Os bivalves de água doce, em particular, apresentam a maioria dos atributos necessários para a colonização de novos ambientes. Um bivalve de grande interesse é o mexilhão dourado Limnoperna fortunei. Originário da Ásia e introduzido na América do Sul em 1991 na Argentina, em pouco tempo se disseminou entre as bacias hidrográficas deste país, do Paraguai, Uruguai, Bolívia e Brasil, com limite de distribuição ao norte registrado na região de Cáceres, Mato Grosso, Brasil. A Bacia Amazônica ainda não apresenta registro do mexilhão dourado. A chegada da espécie na região deverá promover sérios impactos ambientais e econômicos, e sua ocorrência certamente não passará despercebida. O setor mais afetado pela proliferação do mexilhão dourado é o setor elétrico, atualmente, a espécie está presente em 36 usinas hidrelétricas brasileiras, e outras 52 apresentam risco de invasão no período de um ano. Somadas, resultam em aproximadamente 56% da potência instalada total de usinas hidrelétricas no Brasil. Se considerarmos ainda os prejuízos que o mexilhão dourado potencialmente pode gerar a outras fontes de geração de energia que utilizam água para a própria geração e para resfriamento de equipamentos, como as pequenas centrais hidrelétricas (PCH), as usinas termelétricas (UTE) e as usinas termonucleares (UTN), os impactos serão extremos e imprevisíveis. As ferramentas moleculares são de extrema importância para elucidar questões de rotas de invasão e detectar precocemente estágios larvais de L. fortunei. Neste estudo, é proposto um protocolo de utilização de larvas no estudo do perfil genético de populações, permitindo estudar a espécie em regiões de difícil acesso às populações adultas e entender de forma mais aprofundada os processos de invasão. Palavras chave Fouling, bioinvasão, mexilhão dourado, incrustação, protocolo molecular. / Abstract: Biological invasions are recognized as one of the major threats to natural ecosystems. Ecosystems that are more susceptible to accidental introduction of species are estuarine regions and lakes, since many of the exotic and potentially invasive species are aquatic organisms. Freshwater bivalves, in particular, present most of the attributes required to colonize and invade new environments. A bivalve of great interest is the golden mussel, Limnoperna fortunei. Originally from Asia and introduced in South America in 1991, this species soon spread throughout the watersheds in this country, Paraguay, Uruguay, Bolivia and Brazil, reaching the region of Caceres, Mato Grosso, Brazil. The Amazon Basin still has no record of the golden mussel. The arrival of the species in the region should promote serious environmental and economical impacts, and its occurrence certainly will not go unnoticed. The sector most affected by the proliferation of the golden mussel is the electricity-production sector. Currently, 36 Brazilian power plants present the species, and 52 others are at risk of invasion within one year. Together, these power plants represent approximately 56% of the total installed capacity of hydroelectricity in Brazil. If we also consider the damage that the golden mussel can potentially generate to other sources of power generation that use water to generate power and cooling equipment, such as small hydropower, thermal power plants and the thermonuclear plants, the impacts will be unpredictable and extreme. Molecular tools are extremely important to elucidate issues such as invasion routes and to early detect L. fortunei larval stages. In this study, we proposed a protocol to use larvae to determine the genetic profile of populations of the golden mussel, allowing study of the species in regions of difficult access to adult populations and a better understanding of the processes of invasion. Key words Fouling, bioinvasion, golden mussel, molecular protocol.

Thesis (Ph. D.)--Rhodes University, 2005. / Title from PDF t.p. (viewed on July 21, 2006). Includes bibliographical references (p. 251-270).

Landscape ecology helps in predicting the influence of habitat fragmentation on populations. Marine protected areas (MPAs) are expected to create areas of good quality patches and so improve connectivity among shores. MPAs are believed not only to protect adult populations, but also to enhance recruitment both within MPAs and on surrounding exploited shores, therefore improving their ability to recover from overexploitation. As such, MPAs are a preferred management tool for the conservation of natural populations. Although MPAs have been demonstrated to enhance adult abundances, little work has been done on their ability to provide so called "spill-over" of recruits nor has the generality of the influence of MPAs been investigated in a single region with multiple control sites. The Transkei region, on the east coast of South Africa, and the intertidal mussel, Perna perna, offer an ideal system to test the generality of the influence of MPAs on surrounding shores, due to the presence of multiple MPAs and exploited control sites. Patterns of adult abundance were surveyed at four MPAs and two comparably sized exploited control sites. Adult abundances were, in general, found to be higher within MPAs than at exploited control sites, with adult abundances decreasing towards the edge of MPAs and decreasing even more on the outside shores. To simplify the sorting procedure for samples of mussel recruits, a new method using fractionated elutriation was devised and tested. This new method was found to be more accurate, although not statistically significant but also substantially more time consuming. The increase in accuracy although not statistically significant could be biologically significant, especially when looking at low numbers. This new method could, therefore, be very useful especially when [...] is low. Recruitment was estimated over three months during the main reproductive season at two of the MPAs and at appropriate control sites. I predicted that recruitment patterns would mirror the patterns found in adult abundances and that there would be directionality in patterns of recruitment, with northern sites having greater recruitment due to the direction of near-shore ocean currents. Contrary to this, there were no correlations between adult abundance and recruitment for any of the months or sites, with no clear spatial pattern of recruitment in any of the three months. There was, however, a slight trend of greater recruitment at northern sites. To explain the lack of consistency in recruitment and adult abundances, wind data were used to examine the near-shore surface currents in this area, with theoretical surface currents showing similar patterns to those observed for recruitment. From a landscape perspective, the good patches created by MPAs supply recruits to the surrounding matrix but the low quality of habitat in the matrix prevents rehabilitation. The quality of the matrix must therefore be first improved by reseeding these shores. These results emphasise that while MPAs may function in protecting adult abundances, their influence on supplying recruits and hence recovery of near-by exploited shores may be overestimated. This lack of influence on near-by exploited shores highlights the need for reseeding of shores in conjunction with suitable management plans.

Within landscapes, spatial heterogeneity is common and specific landscape features can influence propagule dispersal by wind or water, affecting population connectivity and dynamics. Coastline topographic features, such as bays and headlands, have a variety of biophysical effects on nearshore oceanography, larval transport, retention and supply, and the processes of larval settlement and recruitment. Although this has been demonstrated in several parts of the world, engendering a perception of a general ‘bay effect’, few studies have investigated this generality in a single experiment or region, by replicating at the level of ‘bay’. The Agulhas biogeographic region of the south coast of South Africa is a useful system within which to test for such generality. Using the intertidal mussels Mytilus galloprovincialis and Perna perna as model organisms, patterns of adult distribution were surveyed across four large ‘halfheart’ bays and intervening stretches of open coast, providing replication at the level of ‘bay’ and duplication of ecologically similar species. In support of a general, pervasive influence of bays on intertidal populations, mussel cover was found to be greater in bays than on the open coast for both species, although the effect was strongest for M. galloprovincialis. To explain this adult distribution, settlement, post-settlement mortality and recruitment were examined over 12mo at the same sites, with the prediction that rates of each would favour larger bay populations. Contrary to this, an interaction between month and bay-status was found, with greater settlement and recruitment on the open coast than in bays reflecting extreme settlement and recruitment events at 3 westerly open coast sites during summer. Re-analysis excluding these outliers, revealed the expected effect, of greater settlement and recruitment in bays. While this indicates the broad generality of the bay effect, it highlights exceptions and the need for replication in time and space when examining landscape effects. Measuring post-settlement mortality required testing small-scale settlement behaviour on established and newly deployed settler collectors. It was found that all settlers preferred collectors with biofilm, but that primary settlers avoided conspecific settlers, while secondary settlers were attracted to them. With discrepancies in settler attraction to new and established collectors accounted for, initial (over 2d) and longer-term (over 7d) post-settlement mortality rates were found to be substantial (ca 60 %) for both species. No topographic effect on p-s mortality was evident. Finally, recruit-settler, adult-recruit and interspecies correlations were examined at regional and local scales. Synergistic (or neutral) effects maintained the initial settlement pattern in recruit and adult populations regionally, but not at local scales; striking interspecies correlations suggested the influence of common regional transport processes. Ultimately, the results emphasize the importance of the direction of effects in different life stages and at different spatial scales, and the possibility that antagonistic effects may mask even strong patterns.

[pt] A aplicação dos mexilhões como bioindicadores de poluição por hidrocarbonetos policíclicos aromáticos (HPA) vem sendo amplamente empregada ao redor do mundo com ótimos resultados para o monitoramento desses poluentes, em que no caso do Brasil a espécie Perna perna é a mais comumente estudada para este fim. No entanto, devido à restrição desse organismo as áreas mais rasas faz-se necessário encontrar bioindicadores alternativos ao mexilhão. No presente estudo o organismo empregado para este fim é a esponja marinha Hymeniacidon heliophila. Amplamente distribuída pelo litoral brasileiro essa espécie apresenta condições satisfatórias para ser um bioindicador, tais como sensibilidade, fácil identificação e capacidade de fornecer material suficiente para análise. Devido à sua importância sócio-ecônomica e ambiental a Baía de Guanabara foi uma das áreas de estudo escolhidas para o presente trabalho e que a partir de estudos pretéritos sabe-se que apresenta contaminação por HPAs. A outra região de estudo é localizada nas Ilhas Costeiras – Cagarra, Comprida e Palmas – constituintes da unidade de conservação de proteção integral conhecida como Monumento Natural das Ilhas Cagarras, localizando-se no litoral da Zona Sul da cidade do Rio de Janeiro e que apesar de encontrar-se preservada da atracação de navios sofre a influência da pluma de esgoto liberada pelo Emissário Submarino de Ipanema. A determinação de 37 HPAs foi realizada através da cromatografia gasosa acoplada ao espectrômetro de massas nos quais estão incluídos os 16 HPAs prioritários de acordo com a USEPA além das 5 séries de alquilados homólogos. Os resultados encontrados nas esponjas coletadas durante os meses de agosto e setembro apresentaram um padrão preferencial de acumulação dos compostos mais pesados com valores entre 0,07 e 793,29 ng.g(-1) para a concentração total de HPA, enquanto que para os mexilhões as concentrações variaram de 0,07 a 1658,73 ng.g(-1). Comparativamente as esponjas apresentaram resultados satisfatórios no que tange à capacidade em bioacumular HPAs em relação aos mexilhões. / [en] The use of mussels as bioindicators of pollution by policyclic aromatic hydrocarbons has been widely applied around the world with great results for the monitoring of these pollutants, in Brazil the specie Perna perna is the mostly used for this porpuse. Nevertheless, due to the restriction of this organism in shallow areas is required to discover alternative bioindicators to the mussel. In the present study the organism utilized for this is the marine sponge Hymeniacidon heliophila. Widely distributed across the brazilian shore, this specie presents great conditions to be a bioindicator, like sensibility, easy identification and capacity to provide enough material for tha analysis. Due its socio-economic and environmental importance Guanabara Bay is one of the chosen areas for the present work as know to be contaminated by PAH. The other chosen region is located at Coastal Islands – Cagarra, Comprida e Palmas- constituent of the unit of conservation of integral proteccion known as Natural Monument of Cagarras Islands, located in the litoral of the South Zone of Rio de Janeiro city and spite of being preserved from the mooring of ships suffers the influence of the sewer plume released by the Submarine Emisary of Ipanema. The determination of 37 PAHs was held through gas chromatography coupled mass spectrometer wich is included the 16 priority PAHs according to the USEPA beyond the 5 akylated series. The results found in the coleted sponges durying the months of august and september presented a preferencial pattern of acumulation of the heavy compounds and the values ranged from 0,07 to 793,29 ng.g(-1), for the mussels the concentrations ranged from 0,07 to 1658,73 ng.g(-1). Comparatively the sponges presents satisfactory results related to the capacity of bioacumulation of HPAs of the mussels.

Coastal transition zones form important interlinking regions where marine ecosystems, rivers and estuarine environments significantly influence each other. Coastal rocky shores are key habitats that sustain a variety of primary producers and invertebrates and due to the dynamic nature of coastal ecosystems, suspension-feeders on rocky shores can be influenced by an array of autochthonous and allochthonous food sources. Fatty acid and stable isotope trophic markers were employed to distinguish between regional and temporal changes in the potential food sources to rocky shore suspension-feeders in the Eastern Cape Province of South Africa. The primary aim was to assess the spatial and temporal influences of contrasting river flows on the available food sources to three indigenous coastal suspensionfeeders, namely the volcano barnacle Tetraclita serrata, brown mussel Perna perna and tubebuilding polychaete Gunnarea capensis. This was done by examining the intra- and interspecific changes in the fatty acid and stable isotope signatures of the barnacles, mussels and polychaetes in the adjacent marine environment of a freshwater-restricted (Kariega) and freshwater-dominated (Great Fish) estuary during austral summer and winter. Multivariate and Kruskal-Wallis analyses of variance on the fatty acid and isotopic signatures, respectively, identified significant regional changes in the barnacles and mussels, while only stable isotopes distinguished between the Kariega and Great Fish polychaetes (P < 0.05). In addition, significant temporal changes were observed in consumer fatty acids and isotope values in both regions (P < 0.05). Bacterial sources, detritus and phytoplankton assemblages, which are influenced by hydrology and vegetation, differed between regions and were mainly responsible for the regional and temporal separations. Principal component analyses on the consumer fatty acid signatures distinguished between animals situated upstream (i.e. north) and downstream (i.e. south) of the Kariega Estuary mouth in summer. The north/south separation was mainly due to greater contributions of diatoms to northernlocated animals and dinoflagellates and detritus to southern-located consumers. In addition, the south-flowing Agulhas Current on the eastern shores of southern Africa appeared to influence the north/south separation in the Kariega region, as water leaving the estuary was probably entrained into the south-easterly flowing currents, thereby depositing estuarinederived detritus to southern populations. In general, diatoms and detritus were essential food sources to the filter-feeders in summer, and flagellates, diatoms, zooplankton and detritus were important in winter. Coastal macroalgae was a key food source in the Kariega and Great Fish regions during both seasons. Consistently large levels of diatom markers (16:1n-7 and 20:5n-3) and dinoflagellate markers (22:6n-3) in consumer tissues in the Kariega and Great Fish regions identified that phytoplankton was their dominant food source. The barnacles, mussels and polychaetes had similar fatty acid markers and a fairly narrow δ¹³C range (-16.5 to -14.4 ‰), suggesting that they probably consumed similar food. Carbon isotope analyses, however, separated the suspension-feeders into slightly depleted (barnacles; -16.5 to -16.1 ‰), intermediate (mussels; -15.8 to -15.0 ‰) and enriched (polychaetes; -15.0 to -14.4 ‰) consumers, but did not provide conclusive evidence of their preferences for specific phytoplankton. Conversely, fatty acid analyses highlighted that barnacles and mussels had greater proportions of dinoflagellate markers (22:6n-3; 7.0-15.3 % TFA), while polychaetes had larger diatom levels (20:5n-3; 15.1-22.2 % TFA). In addition, all three species had consistently large contributions from bacterial fatty acids (15:0, i-16:0, 17:0 and i-18:0; 4.2-13.6 % TFA) in summer and winter, and large proportions of saturated fatty acids (33.3-53.1 % TFA) including those with 14 to 18 carbons, indicating that bacterial and detritus food sources played an important role in their diets. Barnacles had small levels of terrestrial markers (18:2n-6 and 18:3n-3; <2.5 % TFA) and demonstrated increased omnivorous feeding compared with the other suspension-feeders [increased levels of 20:1n-11 and 20:1n-9, higher 18:1n-9/18:1n-7 ratios at ~2.1, enriched δ¹⁵N values at ~10.6 ‰; zooplankton (potentially including microzooplankton, larvae and protists) contribution of up to 61 % of the diet]. Mussels contained significant proportions of the terrestrial markers (18:2n-6 and 18:3n-3; >2.5 % TFA) and exhibited intermediate omnivory (intermediate levels of 20:1n-11 and 20:1n-9, intermediate 18:1n-9/18:1n-7 ratios at ~1.3, less enriched δ¹⁵N values at ~7.9 ‰; zooplankton contribution of 10-15 % of the diet). The more depleted nitrogen signatures in the mussels relative to the barnacles and polychaetes possibly illustrated a stronger preference for autotrophic food. Polychaetes mainly consumed plant food sources (i.e. microalgae, macroalgae and detritus; high levels of i-18:0, 18:1n-9, 18:4n-3 and 20:5n-3) and displayed little omnivory (low levels of 20:1n-11 and 20:1n-9, low 18:1n-9/18:1n-7 ratios at ~0.4, intermediate δ¹⁵N values at ~9.1 ‰; zooplankton contribution of <10 % of the diet). The barnacles, mussels and polychaetes are all suspension-feeders, originally presumed to consume the same food sources. The variations observed among the species, therefore, may result from differences in the proportional contributions of the various food sources to their diets as well as distinctions in metabolism. The distinct changes in the fatty acid and stable isotope signatures in all three filter-feeders in the Kariega and Great Fish regions are likely influenced by the diversity in regional vegetation and hydrology in the different systems, combined with interspecific differences in resource partitioning among the species.