Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-08-22T13:31:42Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Thyara Noely Simoes.pdf: 1606100 bytes, checksum: a1162b67299a1fb757baa997c7f7ae73 (MD5) / Made available in DSpace on 2016-08-22T13:31:42Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação - Thyara Noely Simoes.pdf: 1606100 bytes, checksum: a1162b67299a1fb757baa997c7f7ae73 (MD5) Previous issue date: 2016-03-16 / CAPEs / Neste estudo, sangue de fêmeas, cascas de ovos e sedimento do ninho de tartarugas Eretmochelys imbricata coletados durante o período reprodutivo, foram analisados por Fluorescência de Raios X para determinar a presença e as concentrações de Ni, Co, Cu, Hg, Pb e Cr e sua possíveis interferências em alguns aspectos reprodutivos. Todos os elementos foram detectados em baixas concentrações. O Ni foi o elemento encontrado em maiores concentrações nas três matrizes; enquanto o Hg foi encontrado em menores concentrações. As análises demonstraram relação positiva (p<0,05) entre o número de ovos que não eclodiram e a concentração de Cu e Pb no sangue. No entanto, os metais não tiveram influência na produção dos ovos nem na mortalidade dos neonatos; tampouco houve relação direta na transferência materna para as cascas. Assim, metais pesados podem ter alguma influência na reprodução da espécie, mesmo em baixas concentrações. Em concentrações maiores, estes poluentes podem ser importantes limitantes da reprodução de tartarugas marinhas. / In this study, blood, egg shells, and nest sediments of sea turtles Eretmochelys imbricate, collected during reproductive period, were analyzed by X- Ray fluorescence to determine the presence and concentrations of Ni, Co, Cu, Hg, Pb and Cr and their possible interference in some reproductive data. All elements were detected in low concentrations. Ni has been found in higher concentrations in three matrices; while Hg was found in lower concentrations. Our analyses demonstrated significant relationship (p < 0,05) between the unhatched eggs and blood concentrations of Cu and Pb. However, the metals did not have influence on egg production nor on newborn mortality; furthermore, no evidence of transference from mother to eggshells was found. Thus, heavy metals may have some influence on the reproduction of Eretmochelys imbricata, even at low concentrations. In higher concentrations, these pollutants may have important influence in reproduction of sea turtles.

Submitted by Caroline Falcao (caroline.rfalcao@ufpe.br) on 2017-05-22T17:27:10Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_BeatrizLavoranteFinal_BC.pdf: 2045652 bytes, checksum: 19f106b93f6d316fc93419a636ca837a (MD5) / Made available in DSpace on 2017-05-22T17:27:10Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Tese_BeatrizLavoranteFinal_BC.pdf: 2045652 bytes, checksum: 19f106b93f6d316fc93419a636ca837a (MD5) Previous issue date: 2014-08-29 / O Complexo Industrial Portuário-SUAPE, localizado no complexo estuarino de Suape (Pernambuco, Brasil), conta com grandes empresas das mais diversas atividades produtivas. A região possui grande importância ecológica e econômica e estudos relatam a ocorrência de modificações fisiográficas, hidrológicas e ecológicas desde a implantação de SUAPE. Segundo estudos ecotoxicológicos realizados, a área apresenta contaminação moderada e variável. Contudo, ainda não foi possível indicar quais substâncias poderiam estar relacionadas com a toxicidade das amostras ambientais. Neste sentido, o teste de Avaliação e Identificação da Toxicidade – AIT surge como uma importante ferramenta, pois permite a identificação de contaminantes potencialmente causadores da toxicidade. O emprego de um ensaio ecotoxicológico rápido com um organismo-teste sensível antes e após as manipulações de AIT é necessário para este tipo de análise. Os náuplios de copépodos, dentre estes o da espécie Tisbe biminiensis, têm sido indicados para avaliação de amostras de água marinha devido a maior sensibilidade dos estágios larvais, porém o teste normalmente é realizado em microplacas o que o torna bastante laborioso. Este trabalho teve como objetivos aprimorar um protocolo para realização de bioensaios com náuplios de T. biminiensis e avaliar sua sensibilidade usando uma substância de referência, no caso o sulfato de zinco. Posteriormente, o teste foi empregado na avaliação da toxicidade de amostras de água superficial coletadas em diferentes pontos de Suape entre os anos de 2011 e 2013. Visando aumentar a sensibilidade do método, além dos parâmetros de mortalidade, desenvolvimento e inibição, também foram avaliados tamanho e estágio de desenvolvimento dos copepoditos. Para AIT foram estudadas amostras de água superficial coletadas em Abril e Setembro de 2013, sendo realizadas análises químicas de metais, amônia, hidrocarbonetos e agrotóxicos neste último mês. O tempo de duração do teste foi definido em 72 horas. Os testes de alimentação utilizando as microalgas Chaetoceros gracilis e Thalassiosira fluviatilis com e sem adição de ração para peixe demonstraram o pior desempenho de T. fluviatilis sem adição de ração como alimento. Foi verificado que o desenvolvimento nas concentrações de C. gracilis superiores a 2,5 x 105 células mL-1 foram estatisticamente maiores do que controle (água do mar sem adição de alimento) quando na temperatura de 28°C após 72 h. Entretanto a 25°C após 72 horas, apenas a partir da concentração de 5,5 x 105 células mL-1 de C. gracilis, o desenvolvimento dos náuplios para copepoditos foi superior ao controle, indicando que a temperatura de 28°C promove maior desenvolvimento. Logo, foram definidas as seguintes condições para o teste: concentração de C. gracilis de 2,5 x 105 células mL-1 , temperatura de 28°C e um tempo de 72 h. Após os sete testes de sensibilidade foram estimadas as CE50/72h, CL50/72h e a CENO em 3,25 ± 0.59; 3,46 ± 0.72 e 2,0 mg L- 1 para o ZnSO4.7H2O, indicando que os náuplios de T. biminiensis são tão sensíveis quanto outros copépodos frequentemente empregados em estudos ecotoxicológicos. Avaliando-se amostras de água superficial coletadas na região de Suape verificou-se a presença de toxicidade sub-letal para os náuplios de T. biminiensis, mais associada ao mês de Setembro, início do período seco. Dentre os parâmetros avaliados, a inibição foi o que mais indicou toxicidade, seguido pelo desenvolvimento. Apesar da obtenção das medidas dos comprimentos total e da cabeça (geral e por estágio de copepoditos) e da frequência de estágios reduzirem a praticidade do método, em um dos pontos de coleta elas aumentaram a detecção de efeitos tóxicos. O estudo de AIT indicou que os compostos orgânicos, os metais e a amônia seriam os principais agentes causadores da toxicidade das águas de Suape, sendo os resultados da caracterização da fase I do AIT considerados bastante complexos. Nas análises químicas, os Hidrocarbonetos Aromáticos de Petróleo Dissolvidos ou Dispersos estavam em níveis subletais, os agrotóxicos não foram detectados e houve diminuição das concentrações de Fe após a macroalga Ulva sp. A adição de novos parâmetros no teste com náuplios T. biminiensis foi importante para confirmação dos resultados obtidos. A variedade de agentes tóxicos indicados pode ser atribuída à diversidade de atividades realizadas na área, às diferentes influências sofridas pelos pontos estudados e ao regime de chuvas, marés e correntes, indicando a necessidade de monitoramento e avaliação constantes das condições ambientais da região. / The Suape estuarine complex (Pernambuco, Brazil) is located close to the industrial port complex-SUAPE which includes major companies from various productive activities. The region has great ecological and economic importance, and studies have reported the occurrence of physiographic, hydrological and ecological changes since the implementation of SUAPE. According ecotoxicological studies, the area has moderate and variable contamination. However, has not yet been possible to indicate which substances could be related to the toxicity of environmental samples. In this sense, the test for Toxicity Identification and Evaluation - TIE emerges as an important tool because it allows the identification of possible toxic agents. The use of a fast ecotoxicological test with a sensitive test organism before and after the manipulations of TIE is required for this type of analysis. The copepod nauplii, among these the species Tisbe biminiensis, have been indicated for evaluation of samples of estuarine and sea water due to increased sensitivity of the larval stages, but the test is usually performed in microplates which makes it very laborious. This study aimed to improve a protocol for conducting bioassays with nauplii of T. biminiensis and evaluate their sensitivity to zinc sulphate, a reference substance. Subsequently, the test was used to evaluate the toxicity of surface water samples collected at different points of Suape between the years 2011 and 2013. Aiming to increase the sensitivity of the method, beyond the parameters of mortality, development and inhibition, size and stage of development of copepodites were also evaluated. For AIT were studied samples collected in April and September 2013, chemical analysis of metals, ammonia, hydrocarbons and pesticides were performed in the last month. The duration of the test was 72 h. The feeding test using microalgae Chaetoceros gracilis and Thalassiosira fluviatilis with and without addition of fish ration showed the worst performance of T. fluviatilis as food. It was observed that the development C. gracilis concentrations above 2.5 x 105 cells mL-1 were significantly higher than control (sea water without the addition of food) when the temperature of 28 °C after 72 h. However, at 25 °C after 72 h, only at concentrations of 5.5 x 105 cells mL-1 C. gracilis, the development nauplii to copepodites were higher than the control, indicating that the temperature of 28 °C promotes further development. Then, the following conditions were established for the protocol: C. gracilis at 2.5 x 105 cells mL-1 as food, incubation at 28 °C and 72h duration. After the seven sensitivity tests were estimated CE50/72h, CL50/72h and NOEC of 3.25 ± 0:59; 3.46 ± 0.72 and 2.0 mg L -1 for ZnSO4.7H2O, indicating that the nauplii of T. biminiensis are as sensitive as other copepods employed in ecotoxicological studies. Was detected sub-lethal toxicity of surface water samples for the nauplii of T. biminiensis, more associated to September, early dry season. Among the parameters evaluated, inhibition was the most indicated toxicity, followed by the development. Despite obtaining measurements of the total length and head (general and by stage of copepodites) and the frequency of stages reduce the practicality of the method, one of the points, they increased the detection of toxic effects. The TIE study indicated that mainly organic compounds, metals and ammonia would be the toxicity agents of Suape waters, this characterization is considered complex. In chemical analysis, the HAPDDs were at sublethal levels, the pesticides were not detected and concentrations of Fe decreased after Ulva sp. The addition of new parameters in the test Nauplii T. biminiensis was important to confirm the results obtained. The variety of toxic agents can be attributed to the diversity of activities in the area, the different influences suffered by points studied and rainfall, tides and currents, indicating the need for constant monitoring and evaluation of environmental conditions in the region.

Dentre as diferentes poluições presentes nos oceanos, o plástico é provavelmente, aquele que leva aos maiores impactos ambientais, sendo encontrado de praias e manguezais à giros no meio dos oceanos. Os macroplásticos, cujo tamanho é superior a 5mm, são maiores em volume e provocam um impacto socioambiental importante, porém os microplásticos, fragmentos menores que 5mm, estão em maior quantidade e podem provocar danos em organismos marinhos filtradores como mexilhões e ostras. Apesar da sua grande presença nos oceanos, ainda não se estabeleceu com clareza se causam efeitos somente físicos, por um aumento de material particulado não orgânico ingerido, ou se seus efeitos podem ser de origem química, devido à quantidade de contaminantes que possuem. Para estudar o impacto que essas partículas têm em organismos filtradores, o mexilhão Perna perna, espécie bioindicadora abundante na costa brasileira, foi exposto a partículas de polietileno encontradas em cosméticos nacionais. O microplástico foi adquirido diretamente da indústria e precisou ser identificado. A análise de FT&minus;IR mostrou que o plástico era polietileno de baixa densidade. Os organismos então foram expostos ao polietileno, virgem ou lixiviado, em duas concentrações (0,5 g&frasl;L e 2,5 g&frasl;L) por diferentes períodos (12,24,48,96 e 144 horas). Após os experimentos, os mexilhões foram coletados e dissecados e a resposta de seis biomarcadores foi analisada: O Tempo de Retenção do Vermelho Neutro nos hemócitos, Danos ao DNA e Lipoperoxidação nas brânquias e os níveis de três proteínas de estresse (AIF&minus;1, pP38&minus;MAPK e HSP&minus;70) nas glândulas digestivas. Todos os biomarcadores foram afetados pela exposição ao polietileno, porém um padrão no resultado não pôde ser observado. Os fatores de exposição analisados (Concentração, Período e Tratamento do Plástico) individualmente, ou combinados, levaram a respostas diferentes e até mesmo opostas em alguns casos. A coleta de indivíduos de P. perna in situ na região do Porto de Santos mostrou que todos os bancos naturais possuem organismos contaminados. Os resultados deste trabalho mostram que a fisiologia do mexilhão P. perna é modificada após a exposição aguda ao polietileno. Um maior número de biomarcadores deve ser analisado futuramente para elucidar quais vias estão efetivamente sendo ativadas ou inibidas. O alto nível de contaminação dos mexilhões da região do porto de Santos é um fator alarmante que deve ser discutido pela sociedade com o intuito de se criar soluções para o problema da poluição por plástico nos oceanos antes que este afete a saúde humana. / Among all different pollutants, plastic debris is one of the main environmental impacts, being found from beaches and mangrove to gyres in the middle of the oceans. Macroplastics, with size above 5mm, are larger in volume and are an important social and environmental problem, but microplastics, fragments less than 5mm can be most harmful for filter feeding animals such as mussels and oysters. However, it is still debatable if its effects are physical, due to the increase in indigestible material; or chemical, due to plastic additives such as phthalates or PCBs. To study the impact that these particles can have in those animals, the brown mussel Perna perna (Bivalvia) an abundant and an organism easy to maintain in the laboratory, was exposed to virgin or leached polyethylene (PE) microbeads, used as abrasives in Brazilian cosmetics. Polyethylene was acquired directly from the industry and therefore needed to be identified. Analysis of FT&minus;IR showed that the plastic was Low Density Polyethylene. The microplastic exposure had two concentrations (0.5 and 2.5g&frasl;l) and different periods of time (12, 24, 48, 96 and 144 hours). After the experiment, the organisms were dissected and the levels of six biomarkers were analyzed: Neutral Red Retention Time by the Hemocytes, Lipid Peroxidation and DNA Damages in the Gills and the response levels of three stress proteins (pP38&minus;MAPK, AIF&minus;1 and HSP&minus;70) in the Digestive Glands. All biomarkers were affected by the PE exposure, but the results did not follow a pattern. The exposure factors analyzed (Concentration, Period of Time and Plastic Treatment), alone or combined, led to different and sometimes opposite responses. In Situ collected samples in the Santos Harbour area showed that all natural mussel\'s beds analyzed had microplastics contaminated mussels. The results of this work showed that microplastics acute exposure in P. perna modifies its physiology. More biomarkers should be used to clarify which pathways are being activated or inhibited. The high levels of contamination of important commercial mussel\'s beds in the Santos Harbour area, is an alarming sign for the community, that should start working together to solve the plastic pollution problem in our oceans before starts to affect human health.

O principal objetivo deste trabalho é fazer uma análise exploratória a partir da bibliograa disponível, sobre o problema da poluição marinha no Brasil, em particular, da causada por derramamento de óleo. Analisando as principais fontes de poluição, no mundo e no Brasil, seus respectivos impactos ambientais e as metodologias de prevenção, controle, e de resposta adotadas, foi proposto um sistema de vigilância marítimo, capaz de vigiar grandes áreas independentemente das condições de luminosidade e de tempo. São apresentadas duas propostas, ambas baseadas em técnicas de sensoriamento remoto por radar, mas que se diferem principalmente pelas técnicas de aquisição de imagens e de processamento dos dados. Uma já consagrada mundialmente, a RAR (Real Aperture Radar ), e, a outra, a SAR (Synthetic Aperture Radar), que além de operar sob as condições adversas acima mencionadas, é capaz também de obter ótima resolução espacial independentemente da distância do sensor e do alvo. Este estudo demonstra a ineficiência das metodologias adotadas aqui no Brasil, para detectar, avaliar e combater óleo no mar e alerta para as vantagens de se utilizar técnicas modernas de vigilância marítima. / The main objectives of this work are to make a exploratory analysis from the available readings, about the maritime pollution problem in Brazil, particulary that from oil spills. Analyzing the main sources of oil pollution around the world and in Brazil; their environmental impacts, and prevention, control and response methods adopted, a radar maritime surveillance system was proposed to investigate large areas, under rain or sun, at day and night time, agaist oil spills. It is presented two kind of sensor: the first one is RAR (Real Aperture Radar) wich is well known world wide, and the other one is the SAR (Synthetic Aperture Radar), wich is well suited to have good spacial resolution at any distance from the target. This work shows the needs to solve those problems related to maritime pollution in Brazil and the advantages to have a modem system to patrol the sea.

Orientadores: Fosca Pedini Pereira Leite, Giuliano Buzá Jacobucci / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-21T12:16:02Z (GMT). No. of bitstreams: 1 Siqueira_SilvanaGomesLeite_D.pdf: 2460624 bytes, checksum: 11cc560773d9117ec50e5c04d3f4ba0c (MD5) Previous issue date: 2012 / Resumo: O monitoramento dos ambientes marinhos pode ser feito avaliando a presença de poluentes em organismos que são capazes de acumular estas substâncias. Desta forma, este estudo avaliou a presença de hidrocarbonetos petrogênicos na alga parda Sargassum furcatum e em anfípodes ampitoídeos associados provenientes de costões rochosos do Canal de São Sebastião, o qual está sujeito à poluição por petróleo, devido às operações do Duto e Terminais Centro Sul (DTCS) e por efluentes domésticos. Identificou-se as espécies de ampitoídeos que ocorreram associadas ao S. furcatum estudando também a variação espacial e temporal da composição desta comunidade. A relação entre os hidrocarbonetos presentes em S. furcatum, a densidade e a estrutura populacional de Cymadusa filosa, espécie de ampitoídeo mais representativa da região, também foi investigada. Adicionalmente foi realizado o estudo do comportamento reprodutivo de C. filosa e avaliado o seu uso como bioindicador de qualidade da água, por meio de teste de toxidade aguda de curta duração. O material analisado foi proveniente de 7 coletas realizadas entre março de 2007 a novembro de 2008 em 7 costões rochosos. Foram quantificados os hidrocarbonetos alifáticos e policíclicos aromáticos derivados de petróleo tanto na alga como nos anfípodes, que compostos variaram em termos de concentração entre os meses amostrados. A alga possivelmente refletiu as concentrações de hidrocarbonetos presentes na água enquanto que os anfípodes podem ter assimilado via contato direto ou via alimentação. Foram identificadas seis espécies de anfípodes da Família Ampithoidae: Ampithoe sp., A. divisura, A. marcuzzi, A. ramondi, C. filosa e Sunampithoe pelagica que apresentaram diferenças significativas em termos de ocorrência, densidades e variação temporal. A população de C. filosa, de modo geral, foi dominada por jovens, possivelmente devido a elevada fecundidade das fêmeas. Ocorreu também desvio da razão sexual a favor das fêmeas, relacionado com o comportamento diferencial do macho ou devido a sua maior sensibilidade aos hidrocarbonetos presentes na alga. Tanto hidrocarbonetos alifáticos como policíclicos aromáticos influenciaram a densidade e estrutura de tamanho dos diferentes estádios de desenvolvimento de C. filosa. Foram observadas interações agonísticas entre machos e fêmeas de C.filosa, formação de tubos conjugais e a alimentação de filhotes ainda no marsúpio pela fêmea, caracterizando o cuidado parental desta espécie. Verificou-se ainda que o período de incubação dos ovos foi curto e a maturidade sexual ocorreu entre seis a sete semanas. Os resultados de toxidade aguda sugerem que C.filosa tem um potencial para uso em experimentos de ecotoxicologia marinha devido a elevada sensibilidade ao cobre e ao naftaleno, contudo estudos adicionais com outros xenobióticos são necessários para comprovação destes resultados e para validar o uso desta espécie no monitoramento dos ambientes marinhos / Abstract: The monitoring of marine environments can be made by evaluation of pollutant presence in organisms that are able to accumulate these substances. Thus, this study evaluated the occurrence of oil-derived hydrocarbons in the brown algae Sargassum furcatum and in its associated amphitoid amphipods found on rocky shores of the São Sebastião Channel, which is exposed to pollution by oil due to the operations of the Duct and Center Southern Terminal (DTCS) and domestic sewage. The species of amphitoid that occurred associated to S. furcatum were identified, and time and spatial variation of the composition of this community were also studied. The relationship between the hydrocarbons present in S. furcatum and the density and populational stucture of Cymadusa filosa, the most representative species of amphitoid in the area, was also investigated. Additionally a study on the reproductive behavior of C. filosa was conducted and its use as a bioindicator of water quality was evaluated through high toxicity test of short duration. The analysed material was obtained from 7 samples taken from march 2007 to november 2008 on 7 rocky shores. The oil-derived aliphatic and polycyclic aromatic hydrocarbons were quantified both in the algae and in the amphipods. Such compounds varied in concentration between the months of sampling. The algae possibly reflected the hydrocarbon concentrations present in the water while the amphipods may have assimilated hydrocarbons by direct contact or through the trophic chain. Six species of amphipods from the Ampithoidae family were identified: Ampithoe sp., A. divisura, A. marcuzzi, A. ramondi, C. filosa and Sunampithoe pelagica which presented significant differences in occurrence, density and temporal variation. The population of C. filosa in general was dominated by young individuals, possibly due to the high fecundity of the females, and there was a deviation of the sexual ratio favoring the females, related to the male?s differential behavior or due to its higher sensibility to hydrocarbons in the algae. Both aliphatic and polycyclic aromatic hydrocarbons influenced the density and size structure of the different stages of development of C. filosa. Agonistic interactions between male and female C. filosa were observed, formation of share tubes and feeding of the offspring still in the pouch by the female, characterizing parental care by this species. It was also verified that the egg incubation period was short and sexual maturity occurred between six and seven weeks. The results of high toxicity suggest that C. filosa has potential for use in experiments of marine ecotoxicology due to its high sensibility to copper and naphthalene, however, additional studies with other xenonbiotics are necessary to confirm these results and to validate the use of this species in marine environments monitoring / Doutorado / Ecologia / Doutora em Ecologia

M.Sc.

Persistent organic pollutants (POPs), including polychlorinated biphenyls (PCBs) are widespread in aquatic systems, they can bioaccumulate in the tissues of aquatic organisms, especially fish as they occupy a position near the top of the aquatic food web. PCBs are among the most toxic substances and have been shown to cause many adverse effects to humans and wildlife. High health risks are associated with populations that follow a diet high in fat content such as fish and shellfish in which PCBs bioaccumulate. Given the importance of industries and the potential health concerns of exposure to PCBs, the lack of information on environmental levels of PCBs in South Africa (SA) is significant and concerning. Less attention has been directed to analysis of PCBs in the South African environments due to high cost and lack of appropriate equipment. This study was the first conducted in order to assess the levels of PCBs in the environment of Nelson Mandela Bay Municipality (Port Elizabeth). The research was directed at determining the PCB levels in water, sediments, fish and mussels collected in the Nelson Mandela Bay Municipality. The sampling sites, North End Lake (NEL) and Port Elizabeth Harbour (PEH) were selected based on their location and the importance of activities taking place in these areas. In total 456 samples of water (dissolved and particulate phases), sediments, mussels and tissues of fish were analysed. Suitable analytical methods were based on the equipment and materials available at the Nelson Mandela Metropolitan University. Gas chromatography-mass spectrometry (GC/MS) was used to quantify PCBs in the samples using the internal standard method. Six indicator congeners (PCB nos. 28, 52, 101, 138, 153, 180) were chosen because they are mainly present in most PCB mixtures in environmental samples and they are recommended for regular monitoring. These congeners represent about 50% of the total non-dioxin like (NDL) PCBs in food. All these congeners were detected in the samples analysed. The total PCB concentrations in the sediments from the NEL and PEH ranged from 1.60 to 3.06 and from 0.56 to 2.35 ng g-1 dry weight, respectively. The concentrations of total PCBs in Mytilus galloprovincialis ranged from 14.48 to 21.37 ng g-1 wet weight and from 20.84 to 31.34 ng g-1 wet weight in Perna perna. Total PCBs in water ranged from 0.18 to 0.355 ng L-1. The concentrations of total PCBs in the liver, gonads, gills and muscle were 95.69, 57.49, 44.63, 34.14 ng g-1 lipid weight in Cyprinus carpio and 119.73, 59.21, 49.78, 34.63 ng g-1 in Oreochromis mossambicus, respectively. Fish liver was the most contaminated organ due to its high lipid content compared to other parts of fish analysed. The NEL was found to be more contaminated than the PEH. The main potential sources of PCB pollutants in both areas of this study are industrial and municipal discharges. The NEL is surrounded by many industries and serves as a potential pollutant sink due to wastewater and inflow entering into this lake. Four 0.227 kg meals of the edible part of fish (muscle) per month were recommended based on the non-cancer health endpoint and one 0.227 kg meal per month was recommended based on the cancer health endpoint. This research contributed to notify the public and relevant governmental departments on the PCB pollution status of sediments, water and aquatic life in the PEH and NEL.

The mussel bed and its multitude of inhabitants form a life community typical of our intertidal, rocky, open-coast areas. These animals are essentially immobile, are conveniently available at low tide, and have been well defined in their consumer order. Certain main members from this community were chosen with the intention that they would represent an index of heavy metal pollution for a given area under different seasonal and other variable conditions. Samples for monitoring were collected from two different sites. The first site was immediately outside the entrance to San Francisco Bay and located between Seal Rocks and Phelan Beach State Parks. This location was chosen to represent a water mass of supposed maximum pollution. The Golden Gate can be assumed to be the funnel through which flows all waters from the San Joaquin and Sacramento River drainages and from the San Francisco Bay area itself. The second site, immediately north of the Dillon Beach township, located at the juncture of Bodega and Tomales Bays, was chosen since it might represent a water mass of minimum pollution. This area is not immediately near any large urban influence, industrial activity or subject to heavy auto traffic. Therefore, at the outset it was hoped that the “immobile” consumer order within the mussel bed community would reflect the relative pollution of two supposedly different water masses.

Growth of mussels under laboratory conditions was examined under various food regimes in different water types and temperatures. Growth was less than would be useful as an indicator and comparisons with field exposures were of minimal value. The effects of organophosphates on bivalves were examined via toxicity tests, tissue concentration, and by controlling exposure through the use of physical constraints. Upper temperature tolerance of both bivalve species was examined with respect to different acclimation temperatures and organophosphate exposures. Deviations from control exposures occurred at some temperatures. Copper effectively lowered the mean heat coma temperatures of C. fluminea at some concentrations, however, chlorine exposures did not alter heat coma temperature.

Benthic animals have been widely used as health indicators of the marine benthic ecosystems in temperate regions. My PhD thesis mainly aimed to understand the responses of benthic ecosystem in tropical Hong Kong waters to the two management measures - pollution control and trawling ban. My study was based on sediment grab samples collected from 28 stations in three territory-wide surveys conducted in 2001, 2012 and 2015 in Hong Kong waters. I compared the spatial and temporal changes in macrobenthic community structure as well as physical and chemical characteristics of benthic habitats between surveys conducted before and after the pollution control measures in 2001 and 2012, as well as surveys before and after the fishery management measure in 2012 and 2015. The impacts of sewage pollution to benthic ecosystems had been noted in many studies, which included deteriorated water quality and bottom sediment, and disturbed, less diverse macrobenthic community dominated by opportunistic small-sized species. Therefore, sewage treatment and cessation of sewage effluent discharge were expected to lead to notable improvement in benthic habitats, biodiversity and macrobenthic communities; besides, responses of benthic ecosystems to pollution control may be hydrologically varied. In Hong Kong, a series of sewage treatment schemes, e.g. Stage 1 of Harbour Area Treatment Scheme (HATS), Tolo Harbour Action Plan (THAP), Tolo Harbour Effluent Export Scheme (THEES) and a number of sewage treatment works had been conducted in different areas of Hong Kong. Changes in the community structure were noted in the three focal areas with pollution control measures, i.e. Victoria Harbour, Deep Bay and Tolo Harbour; while apparent recoveries were noted inside the Victoria Harbour, the changes in benthic communities inside the Tolo Harbour and Deep Bay could not be attributed to the pollution control measures. Specifically, a decline in nutrient input to the eastern part of Victoria Harbour due to the implementation of HATS might have led to declined sedimentary total organic matter and the disappearance of the opportunistic species, and hence a recovery of benthic ecosystem therein. But in the sheltered Tolo Harbour and Deep Bay, neither improvement in sediment quality nor biodiversity were noted, thus indicating a longer duration is needed for the recovery of benthic ecosystems to take place in these land-locked bays. Degraded marine fishery resources and destruction in marine ecosystems had been noted since the introduction of modern trawling vessels had into Hong Kong since the 1950s and 1960s. Currently, most reports of benthic ecosystem responses to cessation of trawling originate from temperate regions, while it is not well understood for the situation in tropical areas. The territory-wide trawling ban in tropical Hong Kong waters was implemented by the Hong Kong government since December 31, 2012. Although improvement in benthic ecosystems was anticipated after the ban, it was unknown when this would happen and how different parts of the Hong Kong waters would respond to the trawling ban. My study showed that, around 3 years after the trawling ban, sedimentary organic matter content had increased significantly, and bottom water suspended solid loads had decreased in most of the survey stations, indicating territory-wide improvement in the benthic environment. Moreover, significant increases in richness, abundance and functional diversity of macrobenthos, as well as a more aggregated, fewer but larger station groups of macrobenthic communities were also detected after the trawling ban, indicating rapid recovery of the benthic communities. In conclusion, my study indicates that benthic communities in tropical Hong Kong can be used as bioindicators of environmental changes. Due to their restricted mobility, benthic organisms should be an integral part of the ecosystem monitoring aiming to detect the consequences of management measures to the marine environment. Environmental data including habitat complexity and hydrology are also required to fully understand the spatial and temporal dynamics of benthic ecosystems. Besides, my study has provided two territory-wide baseline data on the biodiversity and macrobenthic community structure in the tropical Hong Kong waters, which will be valuable for detecting future changes in the benthic ecosystems. My benthic ecology studies have resulted in a published paper and a manuscript ready for submission for publication. Besides focusing on benthic ecology, I have conducted taxonomic studies on benthic polychaetes, resulting in two published papers. As good taxonomy is the basis of high-quality data in benthic ecology, the training I received from studying these benthic polychaetes has enhanced my understanding of the biology of benthos, which is also important for my career development. However, since these papers do not fall into the main theme of my thesis, they are included in the thesis as appendixes only.