published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

The hearing abilities of elasmobranch fishes were examined in response to several types of stimuli using auditory evoked potentials (AEP). Audiograms were acquired for the nurse shark, Ginglymostoma cirratum, the yellow stingray, Urobatis jamaicensis, in a controlled environment using a monopole underwater speaker. A dipole stimulus was used to measure the hearing thresholds of the horn shark, Heterodontus francisi, and the white-spotted bamboo shark, Chiloscyllium plagiosum. The dipole experiments yielded much lower thresholds than any other experiment, suggesting that this type of sound specifically stimulated the macula neglecta by creating a strong velocity flow above the head of the shark. A shaker table was created to measure the directional hearing thresholds of the C. plagiosum and the brown-banded bamboo shark, C. punctatum. This experiment showed that these sharks could sense accelerations equally in all directions suggesting that they have omnidirectional ears. The results also yielded higher thresholds than with the dipole, suggesting that the macula neglecta was not stimulated as the sharks were being accelerated. An audiogram was also acquired for the Atlantic sharpnose shark, Rhizoprionodon terraenovae, using a monopole speaker in the field. This experiment revealed that the hearing thresholds did not appear to be masked by ambient noise levels, and resulting thresholds yielded the lowest levels detected by any elasmobranch using AEPs. Taken together, these experiments show that sharks are most sensitive to low frequency sounds in the near field and use both their otoconial endorgans as well as the macula neglecta to sense particle motion.

This dissertation combines laboratory and field experiments to investigate the mechanisms of atropisomer enrichment for chiral polychlorinated biphenyls (PCBs) and their metabolites in organisms. Stereoselective biotransformation and bioaccumulation were identified as two major reasons for the different environmental fate of PCB atropisomers. Other affecting factors, such as presence of nanoparticles and changes in feeding ecology of organisms, also affect the fate of chiral contaminants. In vitro incubations of rat cytochrome P-450 2B1 (CYP2B1) isozyme with chiral PCBs indicated that different biotransformation kinetics and competition among PCB congeners or between atropisomers were two main factors affecting atropisomer enrichment. Different interactions between chiral PCB congeners or atropisomers with rat CYP2B1 may occur at the molecular level. Non-racemic meta-hydroxylated-PCBs (5-OH-PCBs) were the major metabolites. CYP-mediated stereoselective formation of dihydroxylated PCBs from OH-PCBs was observed. Gold nanoparticles affected biotransformation activity of rat CYP2B1 and changed PCB atropisomeric composition, directly by electrostatic interaction, or indirectly by changes to the surrounding ionic strength. Thus, stereoselective metabolism of chiral PCBs and OH-PCBs by CYPs is a major mechanism for atropisomer enrichment of PCBs and their metabolites in the environment, with the degree of enrichment dependent, at least in part, on charged nanoparticles and stereoselective interference of atropisomers with each other at the enzyme level. The atropisomer compositions of chiral PCBs were measured in the marine biota of Cumberland Sound (Canada) and Svalbard (Norway). High trophic level organisms, including harp seal, beluga, and narwhal reported for the first time, had species-specific atropisomer signatures, likely due to a combination of in vivo biotransformation and trophic transfer. PCB chiral signatures in Greenland sharks supported the hypothesis that some of these PCB atropisomer compositions shifted over time and space, possibly due to a change in feeding ecology. To our knowledge, this is the first report to investigate temporal trends of PCB atropisomer signatures in Arctic biota.

Shark Bay is a large inverse estuary, located in Western Australia. It has a number of unique habitats that support important species. The dynamics of circulation in Shark Bay have an influence on the species that inhabit the region, on small, local scales as well as on large Bay-wide scales. Numerical modeling and field data were used to examine small-scale dynamics in relation to an important recreational fish, pink snapper (Pagrus auratus). Icthyoplankton surveys collected and recorded egg density in regions where snapper are found. A barotropic three-dimensional hydrodynamic model was coupled with a two-dimensional Lagrangian particle-tracking program to simulate the passive transport of eggs through regions where spawning is known to occur. Circulation modeling results indicated residual flows on small scales that served to retain the eggs in the region where they were originally spawned. Results corroborate genetic work on adult snapper, which found no evidence intermixing of populations in Shark Bay. The numerical model was then further refined to run in a baroclinic mode. Simulations of salinity and temperature gradients were used to recreate frontal systems in Shark Bay. Frontal regions divide the Bay into a northern and a southern section as well as separate it from the ocean. Application of an analytical method for calculating front locations was consistent with the observed results and indicated that the primary forces determining frontal locations in the Bay are tides and gravitational circulation. Winds are a secondary influence, and solar heating is minimal in influence

Thesis (M.S.)--Florida State University, 2006. / Advisor: Timothy S. Moerland, Florida State University, College of Arts and Sciences, Dept. of Biological Science. Title and description from dissertation home page (viewed Sept. 15, 2006). Document formatted into pages; contains x, 33 pages. Includes bibliographical references.

Made available in DSpace on 2014-06-11T19:26:09Z (GMT). No. of bitstreams: 0 Previous issue date: 2012-02-24Bitstream added on 2014-06-13T20:14:46Z : No. of bitstreams: 1 ferrette_bls_me_botib.pdf: 603120 bytes, checksum: f2c62ecea9610761a773e52cb38c0d94 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Para o setor pesqueiro, a identificação e manutenção de estoques diferenciados são fundamentais, pela sua relação direta com a produtividade total e uso sustentável dos recursos, sendo um dos objetivos básicos para programas de controle e conservação de espécies em perigo, a conservação da variabilidade genética. Entre os tubarões mais explorados, as espécies pelágicas apresentam uma maior complexidade na avaliação e monitoramento de suas populações devido às suas distribuições em vastas áreas geográficas. Entre essas espécies, Pseudocarcharias kamoharai, popularmente conhecida como tubarão-crocodilo ou tubarão-cachorro, atinge tamanhos máximos em torno de 140 cm de comprimento total, habita profundidades máximas em torno de 600 metros e ocorre em todos os oceanos tropicais, sendo registrada no Brasil principalmente nas áreas oceânicas do Nordeste. A análise genética molecular realizada utilizando sequências da região controladora do DNA mitocondrial (D-loop) de 125 indivíduos capturados em quatro regiões distintas no Oceano Atlântico (Equatorial Oeste, Noroeste Africano, Golfo da Guiné e Sudoeste Africano) Permitiu identificar 22 haplótipos com diversidade haplotípica h=0.627 e diversidade nucleotídica π=0.00167. Estes índices são similares aos encontrados em outras espécies de tubarões pelágicos também do Atlântico e podem ser considerados dentro dos níveis médios de diversidade genética entre os tubarões. O índice de FST=0.00125 obtido nas comparações pode sugerir ausência de estruturação populacional entre os quatro grupos amostrados. Tendo em vista a contínua inclusão de espécies de tubarões na Lista Vermelha da União Internacional para a Conservação da Natureza e dos Recursos Naturais (IUCN), os resultados obtidos neste estudo podem auxiliar na gestão adequada da pesca e na conservação desta espécie no Oceano Atlântico / For the fishing sector, the identification and delimitation of the fishing stocks constitute fundamental information due to their direct relationship to the overall productivity and sustainable utilization of the resources. This constitutes a basic objective in terms of population management and conservation of endangered species that can be represented by the conservation of the genetic variability. Among the most exploited sharks, pelagic species have a greater complexity in terms of evaluation and monitoring due to their distributions along large geographical areas. One of these species is the crocodile shark, Pseudocarcharias kamoharai, which reaches maximum sizes of around 140 cm in total length, inhabits maximum depths of around 600 meters, and occurs in all tropical oceans including in Brazil, mainly in the Northeast region. The molecular genetic analysis using sequences of the mitochondrial DNA control region (D-loop) of 125 individuals captured in four distinct regions in the Atlantic Ocean (Western Equatorial, Northwest Africa, Gulf of Guinea and Southwest Africa), allowed the identification of 22 haplotypes which revealed a haplotype diversity of h=0627 and a nucleotide diversity of π=0.00167. These indices showed to be similar to those found in other species of pelagic sharks, also from the Atlantic sites and can be considered inside of the average levels of genetic diversity among the sharks. The value of FST=0.00125 index found in the comparisons may suggest the absence of population subdivision among the four sampled regions analyzed. Given the continued inclusion of shark species in the Red List of the International Union for Conservation of Nature and Natural Resources (IUCN), the results obtained in this study may be used to help a more sustainable management of fisheries and conservation programs of this species in the Atlantic Ocean

O tubarão-martelo, Sphyrna lewini é um dos mais valiosos recursos marinhos, e o preço pago por suas barbatanas no mercado Asiático pode atingir acima dos U$ 100,00/kg. A análise da composição de tamanhos e idades nas capturas, o estudo do crescimento desta espécie de grande porte e a evolução temporal dos desembarques, indicaram que este recurso se encontra sobreexplotado no sudeste e sul do Brasil, como reflexo de diferentes modalidades pesqueiras atuando ao longo de todo o seu ciclo de vida e à baixa resiliência desta espécie à pesca, por apresentar um crescimento lento (L&#8734 = 329,12 cm; K = 0,071 ano-1; to = -2,37 ano; sexos combinados), longevidade acima dos 40 anos e mortalidade natural baixa (M = 0,1 ano-1 na fase adulta), padrões estes típicos de uma espécie K-estrategista . A sobrepesca de recrutamento, ocorre nas áreas costeiras, principalmente pela pesca de arrasto e emalhe costeiro, não havendo a proteção das áreas de parto na primavera-verão. Neste caso há grandes capturas de neonatos e juvenis até 8 anos de idade. A tração adulta por sua vez é reduzida pela pesca de espinheI e de emalhe de superfície principalmente na zona de talude. Modelos de análise de covariância indicaram maiores capturas desta espécie na pesca de espinheI de monofilamento de superfície durante os meses de primavera-verão, na zona de talude (200 e 3000 m) e a existência de uma relação linear positiva entre a captura em peso e o esforço em número de anzóis. Medidas de manejo e conservação para esta espécie são sugeridas. / The scalloped hammerhead shark Sphyrna lewini is one of the most valuable marine resources, due to its high-priced fins in the Asian market, which can reach U$ 100,00/kg. The analysis of the length and age composition in the catches, growth studies, and the annual development of its landings in southern Brazil, showed signs of overexploitation for the species. This effect was mainly caused by different fishing gears exploiting all the phases of its life-cycle and its low resilience to fishing pressure due to its slow-growing strategy (L&#8734 = 329,12 cm; K = 0,071 yr-1; to = -2,37 ano; both sexes), longevity (> 40 yrs.) and low natural mortality (M = 0,1 yr-1, during adult phase), which means a K\'strategic typical pattern. Recruitment overfishing use to happen in coastal areas by trawls and anchored gillnets activities which destroy the nurseries and juvenile grounds for the species, mainly in spring-summer months when the parturition occurs. On the other hand, the adult fraction of the stock is reduced by surface longline and driftnets activities along the continental slope. For the surface monofilament longline fisheries, covariance models detected the highest catches of scalloped hammerhead sharks along the slope (between 200 - 3000 m depth), during spring-summer months. There was also a positive linear relationship between catch (in weight) and effort (hook number). Management and conservation measures are recommended for this species.

Made available in DSpace on 2016-09-27T13:40:03Z (GMT). No. of bitstreams: 0 Previous issue date: 2015-09-21. Added 1 bitstream(s) on 2016-09-27T13:45:13Z : No. of bitstreams: 1 000869206.pdf: 1021410 bytes, checksum: f183acbdffb2ad0ddb24e51f8eabd122 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Tubarões e raias estão atualmente entre os vertebrados mais ameaçados de extinção. Tal fato se deve principalmente à exploração pesqueira que permanece sem medidas eficientes de controle em quase todo o planeta, inclusive no Brasil. Considerando-se que cada espécie responde de forma independente às pressões ambientais e principalmente às ações humanas, é de fundamental importância para o desenvolvimento de planos de manejo adequado das suas populações e o ordenamento da exploração sustentável destes recursos que se proceda à caracterização da biodiversidade local, a avaliação das espécies mais capturadas e identificação dos táxons e populações mais suscetíveis à pesca. Contudo, especialmente para os elasmobrânquios, tais parâmetros são de difícil acesso, sobretudo devido às similaridades morfológicas entre as espécies e ainda, devido à prática pesqueira de remoção de partes dos animais como a cabeça e nadadeiras antes dos desembarques, inviabilizando a identificação da maioria das espécies. Segundo os registros de captura de elasmobrânquios elaborados pelo IBAMA nos últimos anos, apenas cerca de 20% dos indivíduos recebem alguma menção quanto à espécie, muitas vezes um nome popular que pode estar relacionado a mais de uma espécie biológica em diversos casos, sendo o restante do produto classificado apenas como cações. A utilização de ferramentas moleculares nos estudos da composição da biodiversidade tem proporcionado sua aplicação em diversas áreas, incluindo na identificação das espécies, no estudo de suas relações evolutivas e no auxílio de programas para a sua conservação. A identificação molecular com a utilização de técnicas do tipo PCR-multiplex e sequências barcode, que identificam características genéticas particulares de cada táxon estão atualmente sendo desenvolvidos e utilizados no reconhecimento das espécies, possibilitando a identificação... / Sharks and rays are currently among the most threatened vertebrate to extinction. This is due mainly to the fact that overfishing remains without effective control measures in almost the entire planet, including Brazil. Considering that each species responds independently to environmental pressures, and mainly to human actions, it is of fundamental importance for the development of appropriate management plans and programming the sustainable exploitation of these resources, to proceed to the characterization of local biodiversity, in the assessment of the species caught, in the correct identification of taxa and the most susceptible populations to fishing activities. However, especially for elasmobranches, such parameters are difficult to access, especially due to morphological similarities between species and also because of the fishing practice of removing parts such as the head and fins before landings, making it impossible to identify the most species. According elasmobranches capture records prepared by IBAMA in recent years, only about 20% of individuals receiving some identification indication, often only a popular name that can be related to more than one biological species, with the remainder fishing product classified just as sharks. The use of molecular tools in studies of the composition of biodiversity has provided its application in various areas, including in the identification of the species, in the study of their evolutionary relationships, and in assisting programs for their conservation. The use of molecular identification techniques as the PCR-multiplex type, and barcode sequences using part of the mitochondrial gene sequence Cytochrome Oxidase subunit I that permit to identify particular genetic characteristics of each taxon, are currently being used in the species recognition allowing simultaneous identification of different samples. In the present work, the objective of the study was to identify the species occurring...

Submitted by HELEN COLBACHINI (hcolbachini@gmail.com) on 2018-04-18T00:26:17Z No. of bitstreams: 1 Helen Colbachini_Dissertação Zoologia.pdf: 2645399 bytes, checksum: 2048a35ec7b7829866e0808d2a32a21a (MD5) / Approved for entry into archive by Adriana Aparecida Puerta null (dripuerta@rc.unesp.br) on 2018-04-18T14:22:04Z (GMT) No. of bitstreams: 1 colbachini_h_me_rcla.pdf: 2470317 bytes, checksum: c173d0ab9c5bac9898e58bb4a42e3e4a (MD5) / Made available in DSpace on 2018-04-18T14:22:04Z (GMT). No. of bitstreams: 1 colbachini_h_me_rcla.pdf: 2470317 bytes, checksum: c173d0ab9c5bac9898e58bb4a42e3e4a (MD5) Previous issue date: 2018-02-19 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / O cação-lixa, Ginglymostoma cirratum, é um dos tubarões mais exibidos em Aquários no mundo, porém a taxa de insucesso reprodutivo desta espécie ainda é alta. Considerando a provável mediação olfativa para a sua reprodução e o potencial de enriquecimentos ambientais afetarem positivamente a reprodução de animais sob cuidados humanos, o presente trabalho objetivou avaliar se a utilização de enriquecimento olfativo geraria efeitos na exibição de comportamentos reprodutivos de cação-lixa, bem como se esse efeito seria diferencial de acordo com o sexo. Este trabalho também propôs avaliar a proximidade física como um indicativo de comportamento proceptivo de fêmeas. O estudo foi dividido em três fases (controle – sem enriquecimento; enriquecimento a curto prazo – recém aplicado; enriquecimento a longo prazo – após incorporado na rotina de manejo) e foi realizado em duas instituições com manejos distintos. O enriquecimento utilizado foi manjericão comercial (Ocimum basilicum), inicialmente apresentado na forma de bloco de gelo e, para o estudo a longo prazo, apresentado na forma de extrato. As observações comportamentais ocorreram através da amostragem focal com registro instantâneo, totalizando 120 horas de observação por animal, divididas em dois momentos (ativo e inativo). Os resultados indicam maior atividade relacionada ao período noturno e às sessões de alimentação; maior frequência de ocorrência de comportamentos reprodutivos no período inativo, no sexo masculino e nas fases com enriquecimento ambiental; maior riqueza comportamental em machos e na fase de enriquecimento a longo prazo. A análise de proximidade mostrou-se eficiente como indicativa de comportamento sócio-sexual, assim como o comportamento “movimento corporal”. É importante atentar que os efeitos são diferenciados para os sexos, sendo essencial o acompanhamento próximo e a criação de cronogramas para evitar uma super-estimulação ou uma habituação ao enriquecimento. Apesar disso, o fato da maior frequência de comportamentos reprodutivos ter ocorrido no período inativo facilita este acompanhamento, visto que se refere ao período de funcionamento de instituições zoológico (dia). Por fim, com a definição dos comportamentos proceptivos faz-se possível determinar quais fêmeas estão receptivas e assim delinear programas reprodutivos mais eficientes. Esses resultados destacam a importância de possuir um manejo que estimule constantemente os sentidos dos elasmobrânquios, especialmente em instituições que desejem realizar programas de reprodução. / Nurse shark, Ginglymostoma cirratum, is one of the most exhibited sharks in Aquariums in the world, however, the reproductive failure rate of this species continues high. Since there probably is an olfactory mediation for its reproduction and environmental enrichments have a potential positive effect on the reproduction of captive animals, the present study aimed to evaluate whether the use of olfactory enrichment would generate effects in the exhibition of reproductive behaviors of nurse sharks, as well as if this effect would be differential according to sex. This study also proposed to evaluate physical proximity as an indicative of proceptive female behavior. The study was divided in three phases (control – without enrichment, shortterm enrichment – recently applied, long-term enrichment – after being incorporated into the management routine) and was performed in two institutions with distinct husbandry. The enrichment used was commercial basil (Ocimum basilicum), which was initially prepared as an ice block and, for the long-term phase, presented as an extract. The behavioral observations were performed through focal sampling with instantaneous recording, totaling 120 hours of observation per animal, divided into two moments (active and inactive). Results show greater activity related to nocturnal period and feeding sessions; greater frequency of occurrence of reproductive behaviors in the inactive period, with males and during the long-term enriched phase. The proximity analysis was efficient as indicative of socio-sexual behavior, as well as the “body movement” behavior. It is important to note that the enrichment effects are differentiated for the sexes and therefore, close monitoring and scheduling are essential to avoid over-stimulation or habituation to the enrichment. Nevertheless, the fact that the greater frequency of reproductive behavior occurred during the inactive period facilitates this monitoring, since it refers to the operating hours of zoological institutions (daytime). Finally, with the definition of proceptive behavior, it is possible to determine which females are receptive and thus, to delineate more efficient breeding programs. These results highlight the importance of having a management that constantly stimulates the senses of elasmobranchs, especially in institutions that aims to carry out breeding programs.

In chapter 1 I describe the population dynamics of an understudied species of gulper shark, Centrophorus uyato (common name, the Little Gulper), found in the Northern Gulf of Mexico. Sharks in the family Centrophoridae are mid-sized, demersal fish, with seven species identified in North American waters. These deepwater species can be difficult to study due to the extreme depths at which they occur. During four longlining cruises from 2012-2014, 593 sharks were landed, predominantly in the Mississippi Canyon off the Louisiana coast. Mean depth of capture was 290 m. Supplementing these data are catch records for C. uyato from a second series of cruises east of these stations. These data suggest the Little Gulper displays sexual dimorphism in its population size structure, similar to other elasmobranchs. Length frequency distributions, sex ratios by length, and length-weight curves were similar for both catch series, however females comprised a greater fraction of the catch from Mississippi Canyon stations compared to those further east. The high incidence of females in the region may indicate the use of Mississippi Canyon as a nursery for C. uyato, and the species' tendency to sexually segregate at some point in its life history. A high number of large, pregnant females, along with observations of recently delivered animals, was noted at the Mississippi Canyon sites. Little Gulper sex ratios by length exhibited a characteristic "notch", indicative of a low female-to-male ratio at intermediate lengths, then a reversal to female dominance at the largest sizes captured. I modeled this curve under various assumptions of growth, mortality, and longevity for the species. The combination of the von Bertalanffy growth parameter, K, and the total instantaneous mortality rate, Z, that best fit the data suggests a population of slow growing, long-lived animals with a differentially higher growth rate for males. In chapter 2, I examine species associations among elasmobranchs in the Northern Gulf of Mexico in relation to depth of capture. From 2011-2014, 3609 sharks, comprising 31 species in 10 families, were landed on five long-lining cruises throughout the Northern Gulf and along the West Florida Shelf. Stations were grouped a priori according to depth into one of three categories, based on pre-existing divisions in the station data: 0-73 m (shallow), 110-146 m (intermediate), and 183 m or greater (deep). Using a non-parametric multivariate analysis of variance (NP-MANOVA) and a pairwise test found I found significant differences in species composition among all three depth groupings. Gulf Smoothhound (Mustelus sinusmexicanus) and Atlantic Sharpnose (Rhizoprionodon terraenovae) contributed most to the differences, and also accounted for over 65% of the total catch. A canonical analysis of principal coordinates (CAP) showed mid-water species such as the Scalloped Hammerhead (Sphyrna lewini) to be more indicative of intermediate depth stations, while the Little Gulper (Centrophorus uyato) and Shortspine Dogfish (Squalus mitsukurii) distinguished deepwater sites. A "leave-one-out cross-validation" (LOO-CV) procedure correctly re-classified 78% of the samples back into their a priori groupings; catches from the shallow and deep groups were never confused for one another, although there was moderate confusion with classifying catches from intermediate stations. Taking into consideration the potentially large movements undertaken by many shark species on both small and large time scales, as well as additional biological and physical drivers for range and location, it is unsurprising that these animals would be present in two or more depth groups, and thus more frequently misclassified. I also performed a second analysis grouping the stations according to their location on the West Florida Shelf, or in the eastern or western quadrants of the Northern Gulf of Mexico. Again I found significant differences among the species composition of all three station groups, but the LOO-CV overall reclassification success rate was lower than when the stations were grouped according to depth. There was also a smaller interval between this reclassification success rate and one performed using random group allocation. Both of these chapters provide data on previously poorly understood species and phenomena in the Northern Gulf of Mexico. These data are important in defining the potential susceptibility of shark species and communities to future threats, including by-catch in fisheries and contamination events such as shallow and deepwater oil spills.