Dissertação(mestrado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2006 / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-11-18T15:49:45Z No. of bitstreams: 1 Beal.pdf: 944473 bytes, checksum: b8b64f4df525f2ad19ff1c3207ace0e6 (MD5) / Approved for entry into archive by Angelica Miranda (angelicacdm@gmail.com) on 2013-11-18T19:23:31Z (GMT) No. of bitstreams: 1 Beal.pdf: 944473 bytes, checksum: b8b64f4df525f2ad19ff1c3207ace0e6 (MD5) / Made available in DSpace on 2013-11-18T19:23:31Z (GMT). No. of bitstreams: 1 Beal.pdf: 944473 bytes, checksum: b8b64f4df525f2ad19ff1c3207ace0e6 (MD5) Previous issue date: 2006 / Os elasmobrânquios são explorados por várias artes de pesca no Rio Grande do Sul. Com o intuito de caracterizar a frota pesqueira de emalhe sediada na fronteira sul do Estado de Santa Catarina, descrever as capturas e a distribuição espacial das espécies de elasmobrânquios na plataforma continental do Rio Grande do Sul, bem como descrever a estrutura populacional de Carcharhinus sp., foram realizadas 34 amostragens de desembarques pela frota pesqueira de Passo de Torres (SC), e nove embarques em viagens de pesca dessa frota, entre novembro de 2004 e março de 2005. O tamanho da frota foi de 30 embarcações, com comprimento total variando entre 10 e 20 m. Neste período, foram utilizadas redes de emalhe de superfície (cação e enchova) e de fundo (corvina, viola e papa-terra). Quinze espécies de tubarões e 12 de raias foram registradas. Entre os elasmobrânquios, Sphyrna lewini teve o maior peso total desembarcado, seguida de Rhinobatos horkelii. Dentre os peixes ósseos, Micropogonias furnieri apresentou os maiores valores de peso total desembarcado. As redes de emalhe de fundo, em especial a de corvina, foram as que mais capturaram exemplares de Carcharhinus sp., que utilizam a área como berçário durante o verão. Os principais problemas para a conservação dos tubarões na região, são a sobrepesca e a captura acidental, que atinge elevado número de neonatos. Sugere-se para a preservação dos tubarões no sul do Brasil, a proibição das redes dirigidas aos elasmobrânquios e a exclusão da pesca nas áreas de hábitat críticas para os neonatos, jovens e adultos. / The elasmobranch fishes are exploited by many fisheries gears in Rio Grande do Sul state. The purposes of this study were to describe the inshore fishery of Passo de Torres (SC), south frontier with Rio Grande do Sul state, to assess the elasmobranchs catches and its composition, and to deliniate their spatial distribution in south continental shelf. Thirty-four landings and nine fishing trips as observer in commercial fishing vessel were monitored, between November 2004 and March 2005. The fleet was compounded by 30 fishing vessels, with size between 10-20 m, and utilized surface and bottom gillnets to capture teleosts and elasmobranch fishes. Fifteen shark and 12 ray species were recorded in this study. Sphyrna lewini had the highest landing in total weight, followed by Rhinobatos horkelii. Among teleosts, Micropogonias furnieri had the highest landing in total weight. The bottom gillnets, specially the one directed for M. furnieri, had the highest capture of Carcharhinus sp., which utilize the area as nursery grounds during the summer. Others elasmobranchs were also by-catch from gillnets. In the study area, the main problems to shark conservation are heavy fishing pressure and by-catch, that capture high numbers of newborn. To shark management in south Brazil, we suggest the exclusion of fisheries with directed gears for elasmobranchs, and the creation of fisheries reserves in these critical habitats for newborn, young and adults.

Submitted by Rafael Santana (rafael.silvasantana@ufpe.br) on 2017-07-14T19:00:48Z No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação Final Maria Carolina Ferraz da Silva.pdf: 977481 bytes, checksum: 9a3d8cadba6deccc41a33a4695f02ce6 (MD5) / Made available in DSpace on 2017-07-14T19:00:48Z (GMT). No. of bitstreams: 2 license_rdf: 811 bytes, checksum: e39d27027a6cc9cb039ad269a5db8e34 (MD5) Dissertação Final Maria Carolina Ferraz da Silva.pdf: 977481 bytes, checksum: 9a3d8cadba6deccc41a33a4695f02ce6 (MD5) Previous issue date: 2016-05-31 / CNPQ / O presente trabalho teve como objetivo analisar prováveis alterações fisiológicas relacionadas ao estresse de captura com espinhel em tubarões-lixa Ginglymostoma cirratum capturados nas praias do Recife e Região Metropolitana. Para tal, a dissertação foi dividida em dois capítulos que abrangem técnicas diferentes para análise do estresse de captura em tubarões. No primeiro capítulo, foi analisada a resposta secundária ao estresse de captura a partir de uma metodologia já bem estabelecida, por meio da análise dos principais íons e metabólitos presentes no sangue. Os animais foram capturados utilizando dois espinhéis lançados próximo ao canal existente entre as praias de Boa viagem, Piedade e Paiva. Diferenças significativas entre os animais capturados e o grupo controle, mantidos em aquários, foram encontradas apenas para os íons magnésio e cálcio. Em relação às diferenças sexuais nos animais capturados, apenas o metabólito lactato mostrou diferença significativa, tendo sido superior nas fêmeas. O íon potássio, apesar de também ter exibido índices superiores nas fêmeas, não apresentou diferença estatisticamente significante. Já no segundo capítulo, o objetivo foi identificar as células sanguíneas encontradas na circulação periférica de tubarões-lixa e utilizar parâmetros hematológicos como a relação entre granulócitos e linfócitos, a contagem diferencial de leucócitos e valores do hematócrito como possíveis indicadores de estresse nesses animais. Foram identificados eritrócitos, linfócitos, monócitos, trombócitos e os granulócitos eosinófilos, neutrófilos e heterofilos na circulação de tubarões-lixa. Apenas um basófilo foi encontrado. Houve significante aumento na relação granulócito/ linfócito (G/L) dos animais capturados em relação ao grupo controle. Os animais capturados apresentaram maior proporção de heterofilos e menor proporção de linfócitos, enquanto o grupo controle apresentou proporções inversas. As fêmeas capturadas apresentaram uma maior relação G/L e uma maior proporção de heterofilos, sugerindo uma resposta mais acentuada ao estresse de captura. Apesar das alterações observadas nos animais capturados, os tubarões-lixa parecem apresentar uma capacidade elevada de resiliência a situações de estresse causadas pela captura, uma vez que todos os animais capturados apresentaram boas condições após sua liberação. / This study aimed to analyze physiological changes related to the stress of capture of nurse sharks Ginglymostoma cirratum caught by longline in the beaches of Recife. To this aim, the dissertation was divided into two chapters covering different techniques for the analysis of stress in sharks. In the first chapter, the secondary response to the stress of capture was analyzed by a well-established methodology, including the analysis of major ions and metabolites present in the blood. Significant differences between the animals caught and the control group, kept in aquarium, were found only for magnesium and calcium ions. With regard to sexual differences among the animals caught, the metabolite lactate was significantly higher in females. The potassium ion, although not significantly different, was also higher in females. In the second chapter, the objective was to identify the blood cells found in the peripheral circulation of nurse sharks and, using haematological parameters, such as the ratio of granulocytes and lymphocytes, the differential leukocytes count and hematocrit values assess the level of stress in these animals. The identified cells were erythrocytes, lymphocytes, monocytes, thrombocytes and granulocytes (eosinophils, neutrophils and heterophils). Only one basophil was found. There was a significant increase in the granulocyte/ lymphocyte (G/L) ratio in captured animals in relation to the control group. The captured animals showed a higher proportion of heterophils and a smaller proportion of lymphocytes, while the control group showed the opposite trend. Captured females showed higher G/L and a larger proportion of heterophils when compared with the captured males, suggesting a more pronounced stress response to capture. In spite of the changes observed in the animals caught, nurse sharks seem to have a high resilience to capture since all captured animals were in good condition at gear retrieval.

A utilização dos produtos provenientes de elasmobrânquios é demonstrada desde os primeiros grupos que habitaram o nosso litoral. Pode-se afirmar estas relações com o estudo dos sítios arqueológicos denominados sambaquis, que foram utilizados pelos grupos de pescadores-coletores do litoral. Analisamos sete sambaquis localizados no litoral do Estado de São Paulo: sambaqui Maratuá, sambaqui do Mar Casado, sambaqui do Buracão, sambaquis Cosipa e sambaqui Piaçaguera (Baixada Santista), sítio Tenório e sítio do Mar Virado (Litoral Norte). Foram analisados 15.447 elementos faunísticos de elasmobrânquios, onde se identificou 16 espécies: tubarão-mangona - Carcharias taurus, tubarão-raposa - Alopias vulpinus, tubarão-branco - Carcharodon carcharias, anequim - Isurus oxyrinchus, Carcharhinus sp., tubarão-cabeça-chata - C. leucas, tubarão-fidalgo - C. obscurus, cação-baleeiro - C. plumbeus, tubarão-tigre - Galeocerdo cuvier, tubarão-azul - Prionace glauca, cação-frango - Rhizoprionodon sp., tubarão-martelo - Sphyrna tiburo, raia-serra - Pristis sp., raia-morcego - Aetobatus narinari, raia-sapo - Myliobatis goodei e raia-ticonha - Rhinoptera bonasus. Os grupos de pescadores-coletores utilizam os dentes, vértebras e ferrões dos tubarões e raias principalmente como instrumentos e adornos. A identificação de espécies de elasmobrânquios em sambaquis demonstra a relação e utilização destes pelo homem, conseqüentemente apresentando grande significância para vários grupos costeiros não só de nossa costa como em todas as regiões do mundo / The use of the originating products of elasmobranchs is demonstrated by them from the first groups that lived in our coast. It is possible to affirm these relations with the study of the archaeological so-called shell mounds, which were used by the groups of fishing-gatherers of the coast. We analyse seven shell mounds located in the coast of the State of São Paulo: sambaqui Maratuá, sambaqui do Mar Casado, sambaqui do Buracão, sambaquis Cosipa, sambaqui Piaçaguera, sítio Tenório e sítio do Mar Virado. 15.447 elements elasmobranchs faunal remains were analysed, where one identified 16 species: sandtiger shark - Carcharias taurus, thresher shark - Alopias vulpinus, white shark - Carcharodon carcharias, shortfin mako - Isurus oxyrinchus, Carcharhinus sp., bull shark - C. leucas, dusky shark - C. obscurus, sandbar shark - C. plumbeus, tiger shark - Galeocerdo cuvier, blue shark - Prionace glauca, sharpnose shark - Rhizoprionodon sp., bonnethead shark - Sphyrna tiburo, sawfish - Pristis sp., bat ray - Aetobatus narinari, eagle ray - Myliobatis goodei e cownose ray - Rhinoptera bonasus. The groups of fishig-gatherers use the teeth, vertebrae and spines of the sharks and you shine principally like instruments and adornments. The identification of species of elasmobranchs in shell mounds, it demonstrates the relation and use of this for the human being, consequently presenting great signification for several coastal groups not only of our coast I eat in all the regions of the world

Freshwater rainbow trout were exposed to 9.2 µg/L total Ag (as AgNO3, a level approximately equal to the 168 h LC50) for 144 h to clarify the toxic mechanism of silver in freshwater teleosts. It was found that silver inhibits active Na+ and Cl- uptake at the gills, resulting in a net loss of both ions from the fish and creating a metabolic acidosis. This leads to a classic stress response (mobilization of cortisol and glucose into the blood plasma), and hyperventilation as a respiratory response to decreased blood pH. Plasma ammonia levels rise without any decrease in ammonia excretion; ammonia excretion later increases. This suggests that the increased plasma levels are due to increased metabolic production. Increased [H+] (decreased pH) results in excess H+ ions in the internal fluids, which are either complexed with ammonia to form NH4+ or are buffered in muscle tissue. The latter results in increased movement of K+ ions into the plasma, which are then excreted at the gills, preventing hyperkalemia. In the end, freshwater teleosts probably die from iono-and osmo-regulatory failure and associated cardiovascular collapse. Seawater teleosts (rainbow trout, tidepool sculpins, English sole, and plainfin midshipmen) and elasmobranchs (Pacific spiny dogfish and long nose skate) were exposed to constant concentrations on total Ag (as AgNO3) ranging from 1.5 to 50.0 µg/L for periods of up to 21 d at salinities of 18 ppt or 30 ppt. These exposure levels are well below those causing acute toxicity in seawater. Silver appears to enter marine teleosts and marine elasmobranchs differently. Seawater teleosts drink the seawater, so the intestines are a major site of silver uptake, along with the gills. Since marine elasmobranchs do not drink, the gills appear to be the sole site of silver uptake from the water. As in freshwater, the liver is the main site for silver accumulation in all marine fish studied. Despite similar terminal liver silver concentrations, marine elasmobranchs have a higher rate of silver accumulation since the livers in elasmobranchs are 10-20 fold larger than in teleosts. Both environmental salinity and exposure concentration play direct roles in determining silver bioaccumulation in marine teleosts. Increasing salinity alters the speciation of silver in the water, which decreases the amount of silver able to enter the fish. Increased silver concentrations mean more silver is available to enter the fish and subsequently cause sublethal toxic effects. Oxygen consumption decreased during the first 7 d of chronic exposure to sublethal silver levels in marine teleosts, with the decrease being more pronounced at higher (still sublethal) silver levels. Ammonia excretion, unaltered during acute exposure (48 h) to high silver levels (250 µg/L), was decreased during the first 7 d of exposure to sublethal silver levels (14.5-50.0 µg/L). This suggests that silver interferes with energy demanding processes such as protein synthesis or iono-regulation. Activity levels of the main enzyme involved in iono-regulation, namely Na+/K+ -ATPase, was affected differently in different fish. In a marine teleost that lives solely in seawater (plainfin midshipmen), silver inhibited the gill ATPase activity after 7 d of exposure, with the inhibition being more effective at higher silver levels. In the tidepool sculpin, a truly euryhaline species, gill ATPase activity increased as the silver levels increased, the latter probably representing a compensatory strategy. Similarly, intestinal ATPase activity was unchanged in the midshipmen, but was increased in the sculpins. Drinking rate in tidepool sculpins, which is involved with both iono-and osmo-regulation, was unaffected by salinity, but was decreased in fish exposed to silver for 8 d. Overall, Ag is far less toxic in seawater than in freshwater, but the mechanisms of toxicity are similar. In both waters, Ag interferes with iono- and osmo-regulation. In seawater, Ag exhibits a significant potential for bioaccumulation and interference with physiological processes during long term low level exposures of marine fish, especially at lower salinity levels. / Thesis / Master of Science (MSc)

Submitted by (edna.saturno@ufrpe.br) on 2017-02-17T13:31:07Z No. of bitstreams: 1 Mirna Regina dos Santos Tambourgi.pdf: 973009 bytes, checksum: e1b23c1d9979ea2656cba5d134038e44 (MD5) / Made available in DSpace on 2017-02-17T13:31:07Z (GMT). No. of bitstreams: 1 Mirna Regina dos Santos Tambourgi.pdf: 973009 bytes, checksum: e1b23c1d9979ea2656cba5d134038e44 (MD5) Previous issue date: 2010-02-17 / In the period from December 2003 to December 2009, the reproductive tract were collected from 201 individuals of Carcharhinus longimanus, caught by of commercial tuna boats in the fleet, who were pelagic longline fisheries and hand line in the area located between latitudes 06 º 45'N and 23 ° 36'S and longitudes 018 ° 44'W and 053 º 13'W. Among the 201 individuals captured, 98 were females (74.5 – 227 cm TL) and 103 were males (72 – 242 cm TL) with a sexual proportion males to females of 1:1. Females were categorized as immature (N = 78; 74.5 – 170 cm TL), matures (N = 13; 165 – 223 cm TL), pré-ovulatory (N = 2; 181 – 187 cm CT) and pregnant (N = 5; 169 – 227 cm TL). The uterine fecundity ranged from 1 to 10 embryos. The cycle of pregnancy is annual with birth occurring at the end / beginning of the year. The size at first maturity of females was estimated at 170 cm TL. Of the 103 males captured, 75 were immature (72 to 160 cm TL), 8 maturing (170 - 196) and 20 were mature (160 - 242 cm TL). The size of sexual maturity was between 160 and 170 cm. / No período de dezembro de 2003 a dezembro de 2009, foram coletados os aparelhos reprodutores de 201 espécimes de Carcharhinus longimanus, capturados por meio de barcos da frota comercial atuneira, que realizaram pescarias com espinhel pelágico e linha de mão, na área localizada entre as latitudes 06º45’N e 23º36’S e as longitudes de 018º44’W e 053º13’W. Deste total, 98 eram fêmeas (74,5 a 170 cm CT), maduras (N= 13; 165 a 223 cm CT), pré-ovulatórias (N= 2; 181 e 187 cm CT) e prenhes (N= 5; 169 a 227 cm CT). A fecundidade ovariana variou de 1 a 10 folículos vitelogênicos e a uterina, de 1 a 10 embriões. O ciclo de gestação é anual com nascimento ocorrendo ao final/início do ano. O tamanho de primeira maturação das fêmeas desta espécie é de 170 cm CT. Dos 103 machos capturados, 75 eram imaturos (72 – 160 cm CT), 8 em maturação (170 - 196) e 20 eram maduros (160 – 242 cm CT). O tamanho de primeira maturação sexual entre 160 e 170 cm.

No description available.

Conservation of elasmobranch populations is often inhibited by a lack of data, particularly in understudied regions like the Red Sea. Survey efforts in this region have been infrequent and often highly localized. Establishing a broad baseline for elasmobranch diversity and abundance along the Saudi Arabian Red Sea coast could inform both conservation efforts and a nascent ecotourism industry. In this thesis, I describe a pilot study comparing biodiversity data from baited remote underwater video stations (BRUVS), unoccupied aerial vehicle surveys (UAVs), and eDNA sequencing at five islands in the Farasan Banks region of the Saudi Arabian Red Sea. Estimates of relative abundance were also compared between the BRUVS and UAVs. Each method identified species missed by the other two, but all three techniques exhibited clear habitat- and taxa-specific biases. I was able to identify key concerns for each approach that need to be addressed before large-scale implementation. If carefully planned and executed well, a full assessment of the Saudi Arabian coastline could establish a true baseline for shallow water elasmobranchs in the eastern Red Sea. Informing best conservation practices and identifying potential ecological attractions in accordance the environmental and economic goals of Saudi Arabia’s Vision 2030.

Elasmobranchs are among the oldest and most successful predators in the ocean, yet one of the most vulnerable to the direct and indirect effects of fishing. Many populations are rapidly declining around the world, and an increasing number is listed as threatened or endangered. The broader ecosystem consequences of these declines, and whether other marine predators can replace sharks, are open questions. In this thesis, I used a diverse set of data and modeling techniques to analyze long-term changes in elasmobranch populations in the Mediterranean Sea, and the consequences of shark declines on marine ecosystems. Because of its long history of fishing, the Mediterranean offers a unique perspective on the response of marine communities to exploitation over long time scales. Here, I reconstructed the history of elasmobranch exploitation over the past 200 years in pelagic, coastal and demersal communities. Results were combined meta-analytically to derive a general pattern of change for the entire region. Overall, I detected multiple cases of regional species extirpations, a strong correlation between historical intensity of exploitation and the stage of community degradation, and some cases of compensatory species increases. My results suggest that compared to other marine ecosystems worldwide, the Mediterranean Sea might be in an advanced stage of overexploitation. To gain more general conclusions about the patterns and consequences of shark declines in the ocean, I reviewed and reanalyzed documented changes in exploited elasmobranch communities around the world, and synthesized the effects of sharks on their prey and wider communities. This work revealed that sharks are abundant and diverse in little exploited or unexploited marine ecosystems but vulnerable to even light levels of fishing. The decline in large sharks has reduced natural mortality in a range of their prey, contributing to changes in abundance, distribution, and behaviour of marine megafauna that have few other predators. In some cases, this has resulted in cascading changes in prey populations and food-web structure. Overall, my thesis greatly enhanced our knowledge about the critical state of elasmobranchs in the Mediterranean Sea and the consequences of the declines of these important marine predators on marine ecosystems.

The objective of this project was to determine if the electromagnetic field (EMF) emissions from undersea power cables impacted the local and transient marine life, with an emphasis on reef fishes. The work was done at South Florida Ocean Measurement Facility of Naval Surface Warfare Center, Carderock Division, Broward County, Florida. This facility functions as the hub for a range of active undersea detection and data transmission cables. It has multiple active submarine power cables that extend several miles offshore and which can deliver power and enable data transmission to and from a range of acoustic and EMF sensors. The cables lie directly on the seabed, are buried in the sand, or are suspended in the water column. EMF emissions from a selected cable were created during SCUBA fish surveys. During the surveys the transmission of either alternating current (AC) or Direct Current (DC) was randomly intiated by the facility with no transmitted current (OFF) provided a control. The surveys were conducted using standardized transect and stationary point count methods to acquire reef fish abundances prior to and immediately after a change in transmission frequency (the divers were aware of the time of frequency change but not the specific frequencies). The divers were also tasked to note the reaction of the reef fishes to the immediate change in the EMFs emitting from the cable during a power switch. The surveys were conducted on a quarterly basis at three sampling sites offshore on the same cable. These sites were in water depths of approximately 5, 10, and 15 m, respectively and were selected based on their robust reef fish community and are representative of each of the three primary hardbottom coral reef habitats in the local offshore environment: the Inner (Shallow), Middle, and Outer (Deep) reef tracts. A total of 263 surveys were conducted: 132 transect-counts and 131 point-counts over 15 months. There were 24,473 fishes counted during transect-count surveys and with point-counts, 36,115 fishes were counted. With count types and sites combine a total of 151 species representing 35 families were recorded. An analysis of the data primarily did not find statistical differences among power states and any variables. However, this may be a Type II error as there are strong indications of a potential difference of a higher abundance of reef fishes at the sites when the power was off. There are a number of caveats to consider with this finding: the data set needs to be larger in terms of numbers of: counts, sites and eletro-sensitive species to allow for rigorous statistical analysis; also a longer time between frequency changes to allow for slower, but nonetheless important, reactions to differing EMFs might lead to differing conclusions. Obviously, more research is required to confirm the results of this study.