Saltmarsh is an important coastal habitat located in the littoral zone of estuaries. Australian saltmarsh area is decreasing due to agricultural and urban development and invasion by mangrove. The aim of the study was to assess the contribution made by saltmarsh as a habitat and a source of food items for fish. Three saltmarsh sites were studied, with Towra Point chosen as a site for detailed ecological study. When corrected for water volume, fish densities were found to be higher within the saltmarsh compared to the adjacent mangrove. Although the fish assemblages in saltmarshes differed significantly from mangroves the overall ratio between commercially and ecologically valuable species in these habitats are similar, a result suggesting the importance of temperate saltmarsh as habitat for economically important fish. Significant export of crab larva from saltmarsh (average crab larval abundance 2124.63 m-3 outgoing water) is a positive contribution to the estuarine food chain supplementing the nutritional requirements of estuarine fish. While the diet of the crabs producing this larvae seems dependant on the saltmarsh environment (given the contrasting isotopic signatures of Sesarma erythrodactyla in saltmarsh and mangrove, and the similarity of isotopic signatures in the saltmarsh for Sesarma erythrodactyla and Helograpsus haswellianus), the crabs do not seem to be dependent on any of the common species of saltmarsh plant, but rather depend on particulate organic matter (POM) derived from local and other sources. Crab larva are a prey item for many estuarine fish, including commercially important species, as evidenced by gut content analysis of fish visiting the saltmarsh flats during spring tides. The results strongly suggest that emphasis be given to ecosystembased management for an estuary rather than component (e.g., vegetation) based managed as defined by the Fisheries Management Act (1994) and the State Environmental Planning Policy 14.

Submitted by Anaclaudia Mattos Villalba (anaclaudiamattosvillalba@gmail.com) on 2016-04-09T22:49:54Z No. of bitstreams: 1 youblisher.com-1121544-Disserta_o_Paulo_Roberto_Santos_dos_Santos.pdf: 1064090 bytes, checksum: eedf7bfcf7e22c42250917e5321c9714 (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-04-21T02:08:25Z (GMT) No. of bitstreams: 1 youblisher.com-1121544-Disserta_o_Paulo_Roberto_Santos_dos_Santos.pdf: 1064090 bytes, checksum: eedf7bfcf7e22c42250917e5321c9714 (MD5) / Made available in DSpace on 2016-04-21T02:08:25Z (GMT). No. of bitstreams: 1 youblisher.com-1121544-Disserta_o_Paulo_Roberto_Santos_dos_Santos.pdf: 1064090 bytes, checksum: eedf7bfcf7e22c42250917e5321c9714 (MD5) Previous issue date: 2015 / O aumento na abundância de peixes não residentes da zona estuarina, atraem o interesse da frota pesqueira, que atua sobre os estoques de forma intensa, muitas vezes levando a sobreexplotação. No estuário da Lagoa dos Patos, a Miragaia (Pogonias cromis), é um peixe estuarino dependente que por muitos anos foi um importante recurso pesqueiro, e hoje encontra-se sobreexplotado e ameaçado de extinção. As capturas que atingiram 1400 t em 1976, decaíram posteriormente e foram inexistentes nos anos de 2004, 2005, 2008, 2009 e 2010. Mas recentemente, se observa o aumento dos desembarques na região. A partir disso, a presente dissertação tem por objetivo descrever a pesca artesanal da Miragaia no estuário da Lagoa dos Patos e analisar o efeito da sobreexplotação no ciclo reprodutivo da população remanescente na região. No primeiro capítulo intitulado "A pesca artesanal da Miragaia (Pogonias cromis, Scieanidae) no estuário da Lagoa dos Patos", é discutida a hipótese de que os maiores valores de esforço e CPUE são encontrados no mesmo período de maior abundância da espécie no estuário, e verifica-se a influência do esforço de pesca nas variações da CPUE. De forma complementar, se confirma a distinta composição dos desembarques entre o período de desova e o resto do ano, a predominância de adultos no período de desova evidencia o aumento da abundância. No segundo capítulo intitulado "O efeito da sobreexplotação no ciclo reprodutivo da Miragaia (Pogonias cromis, Scieanidae)" é discutido a redução da idade e tamanho de primeira maturação sexual e consequentemente fecundidade dos exemplares, como consequência da sobrepesca sofrida pela espécie em anos anteriores. Os resultados encontrados mostram a situação preocupante da população de Miragaias no estuário da Lagoa dos Patos, onde a manutenção da intensidade pesqueira pode levar ao colapso da atividade e posterior extinção local da espécie. / The increase in the abundance of non-resident fish estuarine zone attract the interest of the fishing fleet, which operates on the intensely stocks, often leading to overexploitation. In the estuary of Patos Lagoon, the Black drum (Pogonias cromis) is an estuarine-dependent fish who for many years was an important fishing resource, and today is overexploited and threatened with extinction. Catches reached 1400 t in 1976, declined later and were negligible in the years 2004, 2005, 2008, 2009 and 2010. But recently observed increased landings in the region. Thus, this thesis aims to describe artisanal fishing of Black drum in the estuary of Patos Lagoon and analyze the effect of v overexploitation in the reproductive cycle of the remaining population in the region. In the first chapter entitled "The artisanal fishery Black drum (Pogonias cromis, Scieanidae) in the estuary of Patos Lagoon," discusses the hypothesis that higher values of effort and CPUE are found in the same period of greatest abundance of the species in the estuary, and there is the influence of fishing effort in changes in CPUE in a complementary way confirms the different composition of landings spawning periods for the rest of the year, the prevalence of adults in spawning highlights the increasing abundance. In the second chapter entitled "The effect of overexploitation in the reproductive cycle of Black drum (Pogonias cromis, Scieanidae)" is discussed reducing the age and size at first sexual maturity and consequently fertility of copies as a result of overfishing suffered by the species in previous years. The results show the worrying situation of the population of Black drum in the estuary of Patos Lagoon, where the maintenance of fishing intensity can lead to the collapse of activity and subsequent local extinction of the species.

The aim of this study is to assess the biological accumulation of pesticide residues in aquatic organisms in Sai Gon - Dong Nai (SG-DN) estuary. Fish and mollusks were collected directly at the Soai Rap and Long Tau estuary of the SG-DN river system, washed and separated for taking the tissue. The organochlorine compounds from the tissue were then extracted and analyzed by gas chromatography system. The results showed that, the concentration of OCPs in Tegillarca granosa, Meretrix lyrata, Margaritifera auricularia and Bostrychus sinensis varied from 6.4 to 59.9 μg/kg, 7.2 to 322 μg/kg, 4.5 to 62.1 μg/kg and 2.9 to 114.3 μg/kg fresh weight, respectively. In general, molluscs species that accumulate more heptachlor, aldrin, endrin or dieldrin tend to accumulate less DDT (dichlorodiphenyltrichloroethane). Endosulfan was the most commonly found in three bivalve mollusks while DDTs (1.5–75.2 μg/kg, averaging 8.7 μg/kg weight) was the most popular OCPs in the fish (Bostrychus sinensis) samples. In DDT group, the p,p’-DDT metabolite accounted for the largest percentage, reaching 50% of total DDTs. In HCH (Hexachlorocyclohexane) group, β-HCH isomer was predominant in almost samples. / Mgr đích ccc nghiên cch này là đánh giá tích lũy sinh hhn ccn thuu trr sâu trong các sinh vvn ssnh dưưh nưưh ttư khu vvu ccu sông Sài Gòn - ĐĐn Nai (SG-DN). Cá và nhuyyu thh đưưy llư trry tiiy iicửa sông Soài RRà và Lòng Tàu thuu hh thhu sông SG-DN, đư-D rư- ss-D và tách llc phhh mô thht. Các hhc chh clo hho cơ sau đó đưưđ tách chii và phân tích bbch hh thhh ssh ký khí. Kết quả nghiên cứu cho thấy, dư lượng OCPs tích tụ trong sò điệp (Tegillarca granosa), ngao (Meretrix lyrata), trai nước ngọt (Margaritifera auricularia) và cá bớp (Bostrychus sinensis) dao động tương ứng từ 6,4 đến 59,9 μg/kg, 7,2 đến 322 μg/kg, 4,5 đến 62,1 μg/kg và 2,9 đến 114,3 μg/kg trọng lượng tươi. Nhìn chung, loài nhuyễn thể nào tích lũy nhiều heptachlor, aldrin, endrin hoăc dieldrin có xu hướng tích lũy ít DDT (Dichlorodiphenyltrichloroethane). Endosunfan là nhóm thuốc được tìm thấy nhiều nhất trong các loài nhuyễn thể nghiên cứu. Ngược lại, nhóm DDT lại phổ biến ở cá Bostrychus sinensis (1.5–75.2 μg/kg, trung bình 8.7 μg/kg trọng lượng). Dạng p.p’-DDT trong nhóm DDT chiếm tỷ lệ cao nhất, tới 50% DDT tổng. Trong khi đó, đồng dạng β-HCH của nhóm HCH (Hexachlorocyclohexane) chiếm đa số trong hầu hết các mẫu.

Submitted by Celso Magalhaes (celsomagalhaes@ufrrj.br) on 2017-06-08T13:33:20Z No. of bitstreams: 1 2015 - Samara Macedo Pinto.pdf: 970121 bytes, checksum: f69dfd12be8357633a632969c91a1d3a (MD5) / Made available in DSpace on 2017-06-08T13:33:20Z (GMT). No. of bitstreams: 1 2015 - Samara Macedo Pinto.pdf: 970121 bytes, checksum: f69dfd12be8357633a632969c91a1d3a (MD5) Previous issue date: 2015-05-28 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / Fish communities in developing countries have, in many cases, showed a decrease in the species richness and abundance over time as a result of anthropogenic impacts. We analyzed fish communities of three zones (inner, middle and outer) of the Sepetiba Bay (Southeastern Brazil) using identical sampling methods (bottom trawl) during four different time periods: 1987?1988; 1993?1995; 1998?2001 and 2012?2013. A total of 33,140 fish representing 127 species in 88 genera and 41 families were recorded. Our results revealed highly significant and consistent differences in the fish community structure among the bay zones, and a decreased in the fish richness and abundance over the time period. Changes in fish richness and abundance were related mostly to a sharp decrease that occurred in the inner bay zone, the most impacted bay area, and, to a lesser extent, in the middle zone between the two first (1987?1988 and 1993?1995) and the two latter time periods (1998?2001 and 2012?2013), whereas the outer zone remained comparatively stable over time. Spatial changes in the fish community structure among the bay zones were related to differences in salinity, transparency and depth with this latter variable, together with other factors, acting as a buffer for stabalizing community changes; however, these environmental variables explained little of the variation in the temporal changes. The most important changes over time in abundant species were the numerical decreases of the Ariid Cathorops spixii, the serranid Diplectrum radiale and sciaenid Cynoscion leiarchus, and increases of the sciaenid Micropogonias furnieri and the marine catfish Genidens genidens, with this latter species restricted to the inner and middle zones. This study adds long-term information on gradual fish community changes along spatial gradients of environmental and anthropogenic influences in embayment systems. It is perhaps timely to link conservation and management planning with historical information to protect fish biodiversity in tropical developing countries / As comunidades de peixes em pa?ses em desenvolvimento, em muitos casos, mostram uma diminui??o na riqueza e abund?ncia das esp?cies ao longo do tempo como resultado das evid?ncias dos impactos antropog?nicos. N?s analisamos as comunidades de peixes ao longo de tr?s zonas (interna, central e externa) da Ba?a de Sepetiba (Sudeste do Brasil), utilizando m?todos id?nticos de amostragem (bottom trawl) de peixes durante quatro per?odos temporais diferentes: 1987?1988; 1993?1995; 1998?2001 e 2012?2013. Registrou-se um total de 33.140 peixes representando 127 esp?cies em 88 g?neros e 41 fam?lias. Nossos resultados revelaram diferen?as altamente significativas e consistentes na estrutura da comunidade de peixes entre as zonas da ba?a e uma diminui??o na riqueza de esp?cies e abund?ncia ao longo do per?odo de estudo. As mudan?as na riqueza de esp?cies e abund?ncia foram relacionadas, principalmente, ? uma forte queda que ocorreu na zona interna da ba?a, ?rea esta mais afetada e, em menor medida, na zona central entre os dois primeiros (1987?1988 e 1993?1995) e os ?ltimos dois per?odos temporais (1998?2001 e 2012?2013), enquanto a zona exterior permaneceu relativamente est?vel ao longo do tempo. Mudan?as espaciais na estrutura da comunidade de peixes entre as zonas da ba?a foram relacionadas ?s diferen?as de salinidade, transpar?ncia e profundidade com este ?ltima vari?vel, em conjunto com outros fatores, atuando como um ?buffer? estabilizando mudan?as na comunidade; no entanto, essas vari?veis ambientais explicaram pouco a varia??o nas mudan?as temporais. As mudan?as mais importantes ao longo do tempo em esp?cies abundantes foi a diminui??o num?rica do Ariideo Cathorops spixii, do Serran?deo Diplectrum radiale e do Sciaen?deo Cynoscion leiarchus, e o aumento do Sciaen?deo Micropogonias furnieri e o bagre marinho Genidens genidens, com esta ?ltima esp?cie restrita ?s zonas interna e central. Este estudo acrescenta informa??o de longo prazo sobre mudan?as graduais nas comunidades de peixes ao longo de gradientes espaciais com influ?ncias ambientais e antr?picas no sistema de ba?a. Talvez seja oportuno vincular conserva??o e planejamento de gest?o com informa??es hist?ricas para proteger a biodiversidade de peixes em pa?ses tropicais em desenvolvimento.

<div>Following the 2010 Deepwater Horizon oil spill, extensive research has been conducted on the toxicity of oil and polycyclic aromatic hydrocarbons (PAHs) in the aquatic environment. The location and timing of the Deepwater Horizon surface slick coincided with the spawning seasons of many important pelagic and estuarine fish species. As such, there has been particular emphasis placed on the effects of PAHs on sensitive life history stages in fish, such as the embryonic and larval periods. Additionally, the spill occurred throughout the spring and summer months which, in estuaries, are marked by regular fluctuations in abiotic environmental factors such as dissolved oxygen, salinity, and temperature. Until recently, there has been little work done to elucidate the combined effects that PAHs from oil spills and adverse environmental conditions (hypoxia, increased salinity, and elevated temperatures).</div><div>Work presented in this dissertation uses next generation sequencing technology (RNA Seq) to determine differential gene expression in larval estuarine teleosts following exposure to adverse environmental conditions and PAHs. Downstream canonical pathway and toxicological function analysis were then applied to the identified differentially expressed genes (DEGs) to predict cardiotoxic responses at the organismal level. To verify the predicted responses, a phenotypic anchoring study was conducted and identified a cardiotoxic phenotype (pericardial edema) and reduced cardiac output in embryos exposed to oil. Finally, the mechano-genetic interplay governing the morphological development of the teleost heart was investigated and correlations between developmental gene expression and blood flow forces within the cardiovascular system were identified.</div>