The combined methods of stomach content analysis and stable 15N and 13C isotope biochemistry analysis were used to investigate the trophic dynamics and feeding ecology of coastal pelagic fishes in the waters off southeastern Florida, USA. The coastal pelagic fish complex includes blackfin tuna Thunnus atlanticus, dolphinfish Coryphaena hippurus, king mackerel Scomberomorus cavalla, little tunny Euthynnus alletteratus, skipjack tuna Katsuwonus pelamis, and wahoo Acanthocybium solandri. These coastal teleosts, particularly the tunas and wahoo, are primarily targeted by recreational anglers. However, there is a shortage of available trophic and diet composition data concerning these fishes of the coastal pelagic ecosystem. Stomach and muscle tissue samples were collected from the species of various lengths over a three-year period from March 2010 and March 2013. Across all six species, teleost fishes dominated the prey with an average 64.5% by occurrence, 63.7% by number, and 89.9% by weight. There were two dominant prey families: Clupeidae and Carangidae. Dolphinfish showed the lowest diet overlap among the six species, due to the highly diverse diet. The highest diet overlap occurred between king mackerel and little tunny. The mean δ15N ranged from 8.21 ‰ (wahoo) to 13.18 ‰ (king mackerel), and the mean δ13C ranged from -18.41 ‰ (king mackerel) to -16.70 ‰ (dolphinfish). Blackfin tuna exhibited the largest δ15N range (7.22 to 13.21 ‰), as well as the largest δ13C range (-19.13 to -12.99 ‰). The δ15N and δ13C signatures in the muscle tissue showed evidence of shifts to higher trophic levels with an increase in fish size and the formation of distinct trophic groups among the coastal pelagic predators. The δ13C also suggested an inshore-offshore spatial relationship among the coastal pelagic fish. The trophic dynamics and feeding ecology data generated by this study will provide valuable baseline data for the coastal pelagic complex and future ecosystem studies.

This project was initiated in an attempt to address the paucity of data on Asiatic black bears (Ursus thibetanus) in Mainland China. Field work was carried out from May 2004 – August 2006 within the Tangjiahe National Nature Reserve in northwestern Sichuan Province, China. Initial methodology relied on trapping and GPS radio-collaring bears, but due to extreme difficulty with capturing a sufficient sample size, I expanded the study to include reproduction, feeding analysis from scats and sign, and occupancy modeling from sign surveys. I documented the home ranges of an adult female (100% MCP = 107.5km2, n=470 locations) and a sub-adult female (100%MCP = 5.9km2, n=36 locations) Asiatic black bear. I also documented two birthing occasions with a total of four male cubs produced and eight bear den sites. I collected feeding data from 131 scat samples and 200 bear sign transects resulting in 50 identified food items consumed by Asiatic black bears. I also employed the program PRESENCE to analyze occupancy data using both a standard grid repeated sampling technique and an innovative technique of aging bear sign along strip transect surveys to represent repeated bear occupancy over time. Conservation protection patrolling and soft mast were shown to be the most important factors determining the occupancy of an area by Asiatic black bears in Tangjiahe Nature Reserve, Sichuan Province, China. / Master of Science

[pt] Neste estudo foram determinadas as concentrações de Se e Hg, no tecido hepático, muscular e renal, de 70 golfinhos de cinco espécies diferentes (Tursiops truncatus, Stenella frontalis, Steno bredanensis, Sotalia guianensis e Pontoporia blainvillei) e uma espécie de ave marinha (Sula leucogaster), encontrados mortos, durante os anos de 2001 e 2013, na Costa Centro-Norte fluminense. A fim de identificar o processo de bioacumulação e biomagnificação, foram determinadas as concentrações de Se e Hg no fígado e no músculo de cinco espécies de peixe (Trichiurus lepturus, Micropogonias furnieri, Mugil liza, Sardinella brasiliensis, Scomber japonicus) e um cefalópode (Loligo plei). Para auxiliar no estudo dos níveis de Se e Hg, também foram avaliados os valores dos isótopos estáveis Delta 13C e Delta 15N no músculo de todas as espécies envolvidas. As concentrações mais elevadas de mercúrio e selênio foram observadas no fígado dos golfinhos, que apresentaram valores entre 11,2 e 684 mg kg elevado a potência negativa 1 para o Hg e entre 10,2 e 111 mg kg elevado a potência negativa 1 para Se. No músculo foram observadas concentrações mais baixas de Se e Hg nos golfinhos, apresentando concentrações de Hg que variaram entre 1,8 a 9,8 mg kg elevado a potência negativa 1, e de Se que variaram entre 1,9 a 2,3 mg kg elevado a potência negativa 1. A concentração de Hg no rim variou de 1,5 a 22 mg kg elevado a potência negativa 1 e de Se entre 7,6 a 12 mg kg elevado a potência negativa 1 nos golfinhos. Entre as presas, as concentrações mais elevadas de Hg e Se foram observadas no fígado, o mercúrio variou entre 0,3 e 1,6 mg kg elevado a potência negativa 1 e o selênio entre 6,6 e 40,4 mg elevado a potência negativa 1. As concentrações de Hg muscular ficaram entre 0,45 e 0,046 mg kg elevado a potência negativa 1 e de Se muscular entre 2,3 e 1,4 mg kg elevado a potência negativa 1 nas presas. Os golfinhos apresentaram maior enriquecimento de nitrogênio com valores médios entre 14,0 e 17,5 por mil. Para os isótopos estáveis de carbono, os valores médios variaram entre menos 16,8 e menos 15,5 por mil nos cetáceos. A razão isotópica entre as presas varou entre 8,3 e 13,5 por mil para o Delta 15N e entre menos 18,3 a menos 11,9 para o Delta 13C. Foi observado poder de biomagnificação positivo para o mercúrio nas espécies S. guianenis (log [Hg] = menos 0,031 mais 0,195 asterisco Delta 15 N; r igual a 0,719; p menor 0,001) e S. frontalis (log [Hg] igual a menos 0,15 mais 0,21 asterisco Delta 15 N; r igual 0,68; p menor que 0,0001), sendo possível concluir que a biomagnificação do Hg é efetiva na região estudada. / [en] This study determined the concentrations of Se and Hg in the liver, muscle and kidney tissue, of 70 dolphins from five different species (Tursiops truncatus, Stenella frontalis, Steno bredanensis, Sotalia guianensis and Pontoporia blainvillei) and a species of seabird (Sula leucogaster), found dead during 2001 and 2013 on the North-Central Coast of the State of Rio de Janeiro. In order to identify the bioaccumulation and biomagnification processes, the concentrations of Se and Hg in the liver and muscle of five species of fish (Trichiurus lepturus, Micropogonias furnieri, Mugil liza, Sardinella brasiliensis, Scomber japonicus) and a cephalopods (Loligo plei) were determined. To assist in the study of Se and Hg, Delta 13 C and Delta 15 N stable isotopes in the muscle of all investigated were also evaluated species involved. The highest concentrations of mercury and selenium were observed in dolphin liver, which presented values between 11.2 and 684 mg kg elevated to negative power 1 for Hg and between 10.2 and 111.3 mg kg elevated to negative power 1 for Se. In muscle lower concentrations of Se and Hg were observed for these species, showing Hg concentrations ranging from 1.8 to 9.8 mg Kg elevated to negative power 1, while Se ranged from 1.9 to 2.3 mg kg elevated to negative power 1. Hg concentrations in the kidney varied from 1.5 to 22.0 mg kg elevated to negative power 1 and Se between 7.6 to 12.2 mg kg elevated to negative power 1 in dolphins. Among the prey, higher concentrations of Hg and Se were observed in liver, mercury varied from 0.28 to 1.6 mg kg elevated to negative power 1 and selenium between 6.6 and 40.4 mg kg elevated to negative power 1. Hg muscle concentrations were between 0.45 and 0.046 mg kg elevated to negative power 1 and muscle Se between 2.3 and 1.4 mg kg elevated to negative power 1 in the prey. Dolphins show higher nitrogen enrichment with mean values between 14.0 and 17.5 per thousand. For the stable carbon isotopes, the mean values ranged between less 16.8 and less 15.5 per thousand in cetaceans. The isotopic ratio of the prey ranged between 8.3 and 13.5 per thousand for Delta 15N and between less 18.3 and less 11.9 for Delta 13C. Positive biomagnification power was observed for mercury to species S. guianenis (log [Hg] equal less 0.031 more 0.195 asterisk Delta 15N; r equal 0.719; p less than 0.001) and S. frontalis (log [Hg] equal less 0.15 more 0.21 asterisk Delta 15N; r 10 equal 0.68; p less than 0.0001), and indicating that the biomagnification of Hg is effective in the region studied.

Le premier objectif de ce travail de thèse était de déterminer quel est le degré de ségrégation écologique entre cinq espèces sympatriques de cétacés odontocètes (i.e. le dauphin commun Delphinus delphis, le marsouin commun Phocoena phocoena, le grand dauphin tursiops truncatus, le dauphin bleu et blanc Stenella coeruleoalba et le globicéphale noir Globicephala melas) fréquentant l’aire marine restreinte et très productive du Nord-Ouest de la Péninsule Ibérique (NOPI). Pour cela, des paramètres chimiques ont été analysés dans les tissus biologiques, en tant que “ méthode alternative ” pouvant refléter de façon précise le régime alimentaire et l’habitat de ces animaux à différents échelles de temps d’intégration, et ainsi compléter les informations apportées par des méthodes plus traditionnelles tels que l’analyse des contenus stomacaux ou des fèces, ou encore les données d’observations en mer. Le second objectif de ce travail était d’évaluer l’état de contamination de ces espèces, pour acquérir une base de données de référence complète les concernant et estimer le risque toxicologique auquel elles peuvent faire face. Dans ce contexte, les éléments traces, les isotopes stables du carbone et de l’azote, et les polluants organiques persistants (POPs) sont les paramètres chimiques qui ont été sélectionnés pour répondre aux objectifs fixés.Dans un premier temps, les paramètres chimiques ont été utilisés comme traceurs écologiques des populations (ou de segments de population), procurant une image du régime alimentaire et de l’habitat des espèces à différentes échelles de temps. Nous avons calculé que le réseau trophique du NOPI avait cinq niveaux trophiques, au sein duquel les espèces étudiées occupaient les plus hautes positions, comprises entre 4,3 à 5,3, et sans qu’il y ait de différence significative de position trophiques entre les espèces. Alors que l’analyse d’un seul paramètre chimique ne permettait pas ségréger les cinq espèces, les informations apportées par l’analyse de plusieurs traceurs de long terme (i.e. rapport des isotopes stables du carbone et de l’azote dans les dents et concentrations de cadmium dans les reins) ont révélé une ségrégation de leur niche écologique dans deux des dimensions possibles (les dimensions trophique et spatiale). Cependant, les variations pouvant survenir d’une année sur l’autre ou saisonnières n’ont pas pu être étudiées, excepté pour le dauphin commun, et un chevauchement temporaire des niches ne peut donc pas être totalement exclu. De plus, nous avons montré que les profils de polychlorobiphényles (PCBs) pouvaient être un traceur pertinent de l’écologie trophique d’espèces taxinomiquement proches, en permettant une séparation fine des espèces telles que le marsouin commun et le dauphin bleu et blanc, d’après les différents profiles d’accumulation de ces deux espèces.Dans un second temps, l’état de contamination des espèces dans la zone d’étude a été évalué. Les concentrations ont été interprétées à la lumière des facteurs biologiques et écologiques pouvant influencer ces concentrations, et la bioaccumulation des éléments traces s’est révélée moins prévisible que celle des POPs. Le grand dauphin et le marsouin commun présentaient les concentrations de PCBs les plus élevées par rapport aux autres cétacés odontocètes du NOPI et par rapport à d’autres individus des eaux adjacentes de l’Atlantique Nord-Est.Les résultats principaux de ce travail de thèse ont mis en évidence la pertinence d’utiliser ces paramètres chimiques comme traceurs écologiques, et leur utilité dans la compréhension de la structure et le fonctionnement des écosystèmes à travers le rôle des prédateurs supérieurs. En combinant ces résultats à des informations concernant les activités anthropiques, ce travail peut contribuer au développement et à l’implémentation de mesures de gestion pour ces cinq espèces de cétacés odontocètes du NOPI. / The first objective of this PhD was to determine the degree of ecological segregation between five sympatric species of toothed whales (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus, striped dolphin Stenella coeruleoalba and long finned pilot whale Globicephala melas) inhabiting a restricted and highly productive area, the North West Iberian Peninsula (NWIP). To this end, chemical parameters analyses were used as an “alternative method” of assessing diet and habitat of these animals over different periods of integration, complementing the information given by traditional methods of investigation such as stomach contents, faeces analyses and field observations. The second objective was to evaluate the contamination status of these species in order to estimate the toxicological risk these populations face and to complete the existing database. In this context, trace elements, carbon and nitrogen stable isotopes, as well as persistent organic pollutants (POPs) were selected as chemical parameters for our investigations.Firstly, the chemical parameters were used as ecological tracers of populations (or parts of populations) by drawing an image of the diet and habitat of the species at different time scales. We estimated that the food web has five trophic levels, with toothed whales occupying the top positions, with no significant difference in trophic positions among them, ranging from 4.3 to 5.3. While the analysis of a single chemical parameter did not completely segregate between the five species, the information gained by combining the analyses of several long-term ecological tracers (i.e. nitrogen and carbon stable isotopes in teeth and renal cadmium concentrations) revealed ecological niche segregation in two dimensions of this niche (the trophic and the spatial dimensions). However, year-to-year or seasonal variations could not be investigated, except for in common dolphin, and thus temporary overlap cannot be excluded. Additionally, we showed that polychlorinated biphenyls (PCBs) profiles could be a relevant tracer of the foraging ecology of taxonomically close species, allowing a fine separation of the species as result of their different patterns. This was particularly clear for the harbour porpoise and striped dolphin.Secondly, the contamination status of the species in this area was evaluated, with concentrations interpreted in the light of biological and ecological factors. But the bioaccumulation of trace elements appeared to be less predictable than that of POPs. Bottlenose dolphins and harbour porpoises were found to have higher PCBs concentrations than the rest of the analysed NWIP toothed whales, as well as those of adjacent NE Atlantic waters.The main results of this PhD highlight the relevance of exploiting these chemical parameters as ecological tracers, as well as their usefulness in the comprehensive study of structure and function of ecosystems through the role of top predators. Combined with the information on anthropogenic activities, this work can also contribute to the development and implementation of management plans and mitigation measures for these five species of toothed whales in the NWIP.

<p>Manatees (Mammalia: Sirenia), along with the closely related dugongs, are the only herbivorous marine mammals. Manatees consume a wide variety of vascular plants and algae in both marine and freshwater habitats. However, little is known about what characteristics influence diet and food selectivity, especially in freshwater habitats, which represent a large portion of the available habitat for the endangered Antillean manatee, <italic>Trichechus manatus manatus</italic>, in Central and South America. Understanding foraging ecology is an important element of effective conservation strategies.</p><p>This dissertation investigated various aspects of the foraging ecology of the Antillean manatee in a freshwater habitat, specifically: 1) how plant availability (i.e. species richness, diversity, and abundance) varied seasonally with changes in water depths, 2) manatee food selectivity from a representative set of plant species from that freshwater habitat, and 3) the relationship of plant nutritive compounds and availability with manatee food selectivity. In addition, this dissertation describes the multiple uses of sonar technology for studying manatees and habitat characteristics in freshwater.</p><p>Plant availability to manatees was evaluated by conducting monthly plant surveys from July 2010-July 2011 in four contact lakes in the wetlands of Tabasco, Mexico. Manatee food selectivity was examined by conducting food selection experiments on a wild adult manatee during the low water season with 54 plant species representing 25+ genera. The nutritive components (i.e. crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), hemicellulose (HC), and ash) and plant availability values for selected and non-selected plants species were evaluated to determine their relationship with manatee food selectivity. The applicability of using side-scan sonar for manatee research was tested in various freshwater and estuarine habitats in Honduras, Costa Rica, Panama, and the wetlands of Tabasco, Mexico between 2006-2011.</p><p>The major findings of this dissertation are as follows. Plant species richness, diversity, and abundance were greatest during the rising water season (July-August) and lowest during the low water season (March-June). No plants were available in April-June, which represented the majority of the low water season. The wild manatee</p><p>selected 27 (11+ genera) of the 54 species examined during the feeding experiments. Of the plant characteristics tested (i.e. nutritive components and plant availability), only digestible fiber (HC) was significantly related to manatee food selection, with manatees</p><p>selecting plants with higher HC content. Four unique applications were identified for the use of side-scan sonar to facilitate manatee research in freshwater habitats: 1) confirmation of visual sightings and determination of group size, 2) determination of mother-calf pairs, 3) habitat characterization, and 4) assisting manatee captures.</p><p>Results from this study reveal that manatees living in the freshwater wetlands of Tabasco, Mexico have to cope with a highly seasonal availability of plants and that while manatees consume plants from a wide variety of genera, they are highly selective. Unlike other herbivorous mammals, manatee food selectivity was not influenced by CP, NDF, or ADF, but rather by digestible fiber. A unique suit of anatomical and physiological characteristics suggests that manatees may be fiber digestion specialists. Both seasonal plant availability and the manatee's large dietary breadth must be considered when developing 1) conservation strategies for wild manatees in freshwater habitats and 2) protocols for captive rehabilitation of orphaned and stranded manatees that will be reintroduced into the wild.</p> / Dissertation

No description available.

The first objective of this PhD was to determine the degree of ecological segregation between five sympatric species of toothed whales (i.e. common dolphin Delphinus delphis, harbour porpoise Phocoena phocoena, bottlenose dolphin Tursiops truncatus, striped dolphin Stenella coeruleoalba and long finned pilot whale Globicephala melas) inhabiting a restricted and highly productive area, the North West Iberian Peninsula (NWIP). To this end, chemical parameters analyses were used as an "alternative method" of assessing diet and habitat of these animals over different periods of integration, complementing the information given by traditional methods of investigation such as stomach contents, faeces analyses and field observations. The second objective was to evaluate the contamination status of these species in order to estimate the toxicological risk these populations face and to complete the existing database. In this context, trace elements, carbon and nitrogen stable isotopes, as well as persistent organic pollutants (POPs) were selected as chemical parameters for our investigations.Firstly, the chemical parameters were used as ecological tracers of populations (or parts of populations) by drawing an image of the diet and habitat of the species at different time scales. We estimated that the food web has five trophic levels, with toothed whales occupying the top positions, with no significant difference in trophic positions among them, ranging from 4.3 to 5.3. While the analysis of a single chemical parameter did not completely segregate between the five species, the information gained by combining the analyses of several long-term ecological tracers (i.e. nitrogen and carbon stable isotopes in teeth and renal cadmium concentrations) revealed ecological niche segregation in two dimensions of this niche (the trophic and the spatial dimensions). However, year-to-year or seasonal variations could not be investigated, except for in common dolphin, and thus temporary overlap cannot be excluded. Additionally, we showed that polychlorinated biphenyls (PCBs) profiles could be a relevant tracer of the foraging ecology of taxonomically close species, allowing a fine separation of the species as result of their different patterns. This was particularly clear for the harbour porpoise and striped dolphin.Secondly, the contamination status of the species in this area was evaluated, with concentrations interpreted in the light of biological and ecological factors. But the bioaccumulation of trace elements appeared to be less predictable than that of POPs. Bottlenose dolphins and harbour porpoises were found to have higher PCBs concentrations than the rest of the analysed NWIP toothed whales, as well as those of adjacent NE Atlantic waters.The main results of this PhD highlight the relevance of exploiting these chemical parameters as ecological tracers, as well as their usefulness in the comprehensive study of structure and function of ecosystems through the role of top predators. Combined with the information on anthropogenic activities, this work can also contribute to the development and implementation of management plans and mitigation measures for these five species of toothed whales in the NWIP.

Studies focusing syntopic species help to understand how they partition resources and coexist. The objective of this work was to describe the social system, habitat use and diet of the hoary fox (Pseudalopex vetulus) and the crab-eating fox (Cerdocyon thous), in an area of cattle farms in Central Brazil. It is also reported a confrontation between the two species, observed during a study on the behavioral repertory of the hoary fox. Social system and habitat use were studied by direct observation of foxes in the field and diet, through scat analysis. Crab-eating foxes were found in pairs in 34 (59%) of 58 encounters and hoary foxes were solitary in 58 (84.0%) of 69 encounters, with no seasonal variation in the group size of both species. During one encounter of a crab-eating fox couple, the male vocalized to call the female that had remained behind. Hoary foxes were sighted in grazed pasture in a higher proportion (84%) than crab-eating foxes (67%) and they were never found in forest neither in swamp. Besides, both species were rarely seen together, and the only encounter registered ended in a conflict, with the crab-eating fox driving the hoary fox out. Twenty-seven taxa were identified in the diet of the two canids, with the crab-eating fox (n = 32 scats) consumed fruits, insects (mainly Orthoptera and Coleoptera) and vertebrates (most Cricetidae and Squamata) and the hoary fox (n = 23 scats) ate primarily termites (Isoptera). Results indicate that crab-eating fox couples keep more tight bonds than hoary fox couples. The coexistence of both species may be related to the detected differences in habitat use and diet. / Estudos enfocando espécies sintópicas ajudam a entender como elas partilham os recursos e coexistem. O objetivo deste trabalho foi descrever o sistema social, o uso do habitat e a dieta da raposa-do-campo (Pseudalopex vetulus) e do cachorro-do-mato (Cerdocyon thous), em uma área de fazendas de gado no Brasil Central. Também é relatado um confronto entre as duas espécies observado durante um estudo sobre o repertório comportamental da raposa-do-campo. O sistema social e o uso de habitat foram estudados a partir da observação direta dos animais no campo e a dieta, através da análise de fezes. Os cachorros-do-mato foram encontrados em duplas em 34 (59%) de 58 encontros e as raposas-do-campo estavam solitárias em 58 (84%) de 69 encontros, não havendo variação sazonal no tamanho de grupo das duas espécies. Durante um dos encontros de uma dupla de cachorro-do-mato, o macho vocalizou para chamar a fêmea que havia ficado para trás. As raposas-do-campo foram avistadas em pastagens em uma proporção maior (84%) que os cachorros-do-mato (67%) e nunca foram encontradas em florestas ou brejos. Além disso, as duas espécies raramente foram vistas juntas, sendo que o único encontro registrado terminou em conflito, com o cachorro-do-mato expulsando a raposa-do-campo. Vinte e sete táxons foram identificados na dieta dos dois canídeos. O cachorro-do-mato (n = 32 fezes) consumiu frutos, insetos (principalmente Orthoptera e Coleoptera) e vertebrados (a maioria Cricetidae e Squamata) e a raposa-do-campo (n = 23 fezes) se alimentou principalmente de cupins (Isoptera). Os resultados indicam que casais de cachorros-do-mato mantêm laços mais estreitos que casais de raposa-do-campo. A coexistência de ambas as espécies pode estar relacionada às diferenças detectadas no uso do habitat e na dieta. / Mestre em Ecologia e Conservação de Recursos Naturais

Submitted by Irene Nascimento (irene.kessia@ufpe.br) on 2016-06-20T18:42:06Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação (G. Ferreira).pdf: 2368229 bytes, checksum: e7d27dd236d3848f67692455d0a94426 (MD5) / Made available in DSpace on 2016-06-20T18:42:06Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Dissertação (G. Ferreira).pdf: 2368229 bytes, checksum: e7d27dd236d3848f67692455d0a94426 (MD5) Previous issue date: 2016-02-01 / Capes / Este estudo avalia a influência espaço-temporal nos padrões de distribuição, ecologia alimentar e ingestão de microplástico da espécie Cynoscion acoupa (Pescada Amarela) ao longo da sua ontogenia, no estuário do rio Goiana, localizado no nordeste do Brasil. A área de estudo se trata de um estuário tropical, com altas médias de temperatura anual e pequenas oscilações. O ambiente está submetido a um regime de mesomaré semi-diurna. As principais alterações encontradas no estuário são oriundas do ciclo sazonal, que está diretamente ligado à pluviometria, divida em quatro estações (início da chuva, fim da chuva, início da seca e fim da seeca), com o intuito de se ter uma maior precisão na avaliação dos processos abiológicos e na comunidade aquática. Os espécimes foram coletados em diferentes porções estuarinas (estuário superior, intermediário e inferior) e nos canais de maré. Simultaneamente a coleta dos dados biológicos foram obtidas informações a respeito dos parâmetros físico-químicos. Os padrões de distribuição e alimentação da espécie estudada ocorrem de forma distinta em relação à ontogenia, sazonalidade e áreas do estuário. A fase juvenil de C. acoupa ocupa a porção superior do estuário durante todas as estações do ano, em busca de baixos valores de salinidade, onde encontram condições ideais apara evitar predadores marinhos. As principais presas dos juvenins no estuário superior foram filamentos de microplástico (FO=63%), amphipoda (FO=28%) e mysidacea (FO=22%). Além disso, no início do período chuvoso, o estuário superior apresenta um papel crucial para o ciclo de vida da espécie, por se caracterizar como uma área berçário para C. acoupa (grande densidade 228,4 ind. ha-1 e baixa biomassa 46 g ha-1 de juvenis), pois a sua contribuição de indivíduos juvenis para a população adulta é muito maior que nos outros hábitats. No ambiente de berçário os juvenis se alimentaram principalmente de filamentos de microplástico (FO=48%), camarão (FO=28%), mysidacea (FO=22%) e amphipoda (FO=21%). Nas demais porções estuarinas, também são registrados indivíduos juvenis, sobretudo nos períodos chuvosos (início da chuva 115 ind ha-1 e fim da chuva 7,3 ind. ha-1), porém em menor escala. Os subadultos de C. acoupa utilizam principalmente o estuário superior durante o início da seca (1,7 ind. ha-1), fim da seca (1,6 ind. ha-1) e início da chuva (6,5 ind. ha-1) como área de alimentação. Predando no estuário superior, no início da seca, principalmente peixes não identificados (FO=50%), no fim da seca, filamentos de microplástico (FO=60%), mysidacea (FO=20%) e syllidae (FO=20%) e no início da chuva, filamentos de nylon FO=100% e peixes não identificados (FO=20%). Durante o fim do período chuvoso os indivíduos subadultos migram para o estuário intermediário (2,3 ind. ha-1) para evitar grandes estresses osmorregulatórios e predaram principalmente amphipoda (FO=75%), Cathorops spixii (FO=50%), Anchovia clupeoides (FO=25%) e peixes não identificados (FO=25%). A fase adulta de C. acoupa foi registrada somente nas porções mais externas do estuário inferior, por se tratar de uma espécie de hábitos costeiros quando completamente desenvolvida. Os indivíduos adultos de C. acoupa predaram principalmente filamentos de nylon (FO=100%), C. spixii (FO=18%), Achirus lineatus (FO=15%), Stellifer stellifer (FO=15%) e camarão (FO=15%). C. acoupa apresentou uma variação no padrão de distribuição em relação a sua ontogenia, sazonalidade e diferentes porções estuarinas. Ao longo do seu desenvolvimento ontogenético C. acoupa também apresentou uma alteração na sua guilda trófica, os juvenis e os subadultos foram classificados como oportunistas e os indivíduos adultos como piscívoros. A grande quantidade de fragmentos e microplástico encontrada na espécie estudada, demostra que ela é particularmente vulnerável a esse tipo de contaminante, sobre tudo os espécimes adultos, que registraram os maiores níveis de contaminação, provavelmente em razão do seu nível trófico, como predadores de topo. / This study assess the spatio-temporal distribution patterns, feeding ecology and microplastic ingestion of the Cynoscion acoupa (Acoupa weakfish) during its ontogeny in the Goianna Estuary, located in northeast Brazil. The study area is a tropical estuary, with high mean temperatures and narrow annual temperature variations. The environment is classified as a semi-diurnal mesotidal estuary. The major environmental dynamics are caused by the seasonal regime, which is related to the rainfall, according to the pluviometry, the area was divided in four different seasons (early dry, late dry, early rainy and late rainy). Biological samples were performed in different estuarine reaches (upper, middle and lower estuary) and in tidal creeks. During the fish sampling, environmental parameters were also recorded. The distribution and feeding patters of the studied species occur in a distinctive form according to the ontogeny, seasonality and estuarine area. The juveniles of C. acoupa occupy the upper estuary, during all seasons, seeking low salinity that provide ideal conditions to avoid marine predators. The main juveniles prey in the upper estuary were microplastic threads (FO=63%), amphipoda (FO=28%) and mysidacea (FO=22%). Moreover in the early rainy season, the upper estuary is crucial for the life ciclo of the species, because it is a nursery ground for C. acoupa (high density 228.4 ind. ha-1 and low biomass 46 g ha-1 of juveniles), as a result of the higher contribution of juveniles for to the adult population than in the other habitats. In the nursery ground, the juveniles of C. acoupa fed mainly on plastic threads (FO=48%), penaeid shrimps (FO=28%), mysidacea (FO=22%) and amphipoda (FO=21%). In other estuarine areas juveniles were also recorded, mainly on the rainy seasons (early rainy 115 ind. ha-1 and late rainy 7.3 ind. ha-1), however with lower densities. The subadults of C. acoupa inhabited mostly the upper estuary, during the early dry (1.7 ind. ha-1), late dry (1.6 ind. ha-1) and early rainy seasons (6.5 ind. ha-1) as a feeding ground. In the upper estuary, during the early season they fed mainly on unidentified fish (FO=50%), in the late dry, plastic threads (FO=60%), mysidacea (FO=20%) and syllidae (FO=20%) and in the early rainy, plastic threads (FO=100%) and unidentified fish (FO=20%). During the late rainy season the subadults of C. acoupa migrated to the middle estuary (2.3 ind. ha-1) to avoid osmoregulatory stress, the subadults and fed mainly on amphipoda (FO=75%), Cathorops spixii (FO=50%), Anchovia clupeoides (FO=25%) and non-identified fish (FO=25%). The adults of C. acoupa were recorded only in seaward areas of the lower estuary, as a result of C. acoupa being a coastal/marine species when fully developed. The adults preyed mostly plastic threads (FO=100%), C. spixii (FO=18%), Achirus lineatus (FO=15%), Stellifer stellifer (FO=15%) and penaeid shrimp (FO=15%). During the ontogenetic process, C. acoupa showed a trophic guild shift, the juveniles and subadults were assigned as opportunistic and the adults as psicivores. C. acoupa showed a variation in the distribution pattern in relation to the ontogeny, seasonality and different estuarine reaches. During the ontogenetic development, C. acoupa showed a trophic guild shift, the juveniles and subadults were assigned as opportunistic and the adults as psicivores. The high occurrence of microplastic threads in the species, evince that C. acoupa is particularly vulnerable to this contaminant, especially the adult phase that registered highest contamination levels, probably due its trophic level, as a top predator.

Tese(doutorado) - Universidade Federal do Rio Grande, Programa de Pós–Graduação em Oceanografia Biológica, Instituto de Oceanografia, 2012. / Submitted by Cristiane Gomides (cristiane_gomides@hotmail.com) on 2013-10-11T16:45:36Z No. of bitstreams: 1 Luciano.pdf: 10791164 bytes, checksum: abbbf3e63dd24039e4b6f6fb89af6147 (MD5) / Approved for entry into archive by Sabrina Andrade (sabrinabeatriz@ibest.com.br) on 2013-10-17T17:51:18Z (GMT) No. of bitstreams: 1 Luciano.pdf: 10791164 bytes, checksum: abbbf3e63dd24039e4b6f6fb89af6147 (MD5) / Made available in DSpace on 2013-10-17T17:51:18Z (GMT). No. of bitstreams: 1 Luciano.pdf: 10791164 bytes, checksum: abbbf3e63dd24039e4b6f6fb89af6147 (MD5) Previous issue date: 2012 / Os peixes da família Macrouridae apresentaram uma das maiores biomassas entre os peixes demersais em cruzeiros de pesquisa no Sudeste-Sul do Brasil entre 300-600m. Embora não sejam alvo da pesca no Brasil, estão entre os principais itens no descarte da pesca de arrasto no talude, sofrendo impacto similar às espécies-alvo. Dados de dois cruzeiros sazonais de arrasto de fundo foram utilizados para analisar a distribuição, abundância, densidade, composição de comprimentos e estimativas de biomassas para sete espécies de Macrouridae do talude superior do Sudeste-Sul do Brasil: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis, Lucigadus ori, Hymenocephalus billsam, Ventrifossa macropogon e V. mucocephalus. A biomassa total foi estimada em 5,5 e 8,3 kt, respectivamente, no inverno-primavera e verão-outono, das quais C. marinii e M. occidentalis compuseram 98%. Amostras mensais da pesca comercial foram adicionalmente usadas para analisar a ecologia trófica das quatro espécies mais abundantes no talude superior do Sul do Brasil. Foram analisadas a composição da dieta, as mudanças ontogenéticas, as variações sazonais, a sobreposição alimentar intra e interespecífica, a fauna parasitária e aspectos da morfologia funcional relacionada à alimentação. C.marinii consumiu presas pequenas da infauna, epifauna, plâncton, nécton e carcaças, aproveitando presas em manchas ou agregações. M.occidentalis apresentou certa seleção por presas maiores e de coluna d’água, além de caranguejos e carcaças. As duas espécies apresentaram mudanças ontogenéticas e variações sazonais na composição da dieta, ocasionando mudanças nos padrões de sobreposição, mas em geral houve uma baixa sobreposição alimentar. As distintas morfologias funcionais encontradas refletiram em diferenças na dieta e nas estratégias de alimentação das espécies. Para C.marinii e M.occidentalis foram contruídos mapas com densidades, áreas de desova, índice alimentar, proporções de sexos e de imaturos/maturos, que foram relacionadas aos processos oceanográficos, fornecendo uma visão sobre as estratégias de vida e processos que regulam os padrões de distribuição e abundância. Ambas as espécies apresentaram variação sazonal na extensão e localização das áreas de desova. A maioria das fêmeas de C.marinii estavam maturas (90%), sugerindo que assentam ao fundo simultaneamente à maturação e que os juvenis são pelágicos, enquanto M.occidentalis apresentou muitos juvenis e poucas fêmeas maturas, assentando ao fundo bem antes da maturação. São identificados e descritos três processos responsáveis pelos padrões de distribuição e abundância encontrados nestas espécies. Sugere-se que áreas encontradas com elevadas biomassas de Macrouridae (carniceiros) sejam causadas por zonas de ocorrência semipermanente de processos de mesoescala (e.g. vórtices). Esses processos aumentam a produtividade e possibilitam elevadas biomassas de organismos de vida-curta encontradas em camadas superiores, e por outro lado, aumentam a concentração, mortalidade e disponibilidade de carcaças desses organismos, favorecendo predadores carniceiros. Esses processos podem ser responsáveis por inconsistências nas biomassas de magafauna e macrofauna encontradas em alguns estudos, onde biomassas de megafauna foram da mesma ordem de grandeza ou maiores que as de macrofauna, contradizendo o princípio Eltoniano. / Macrourids are among the most abundant and diverse demersal fishes in all deep oceans, including the Southwestern Brazilian continental slope. Although not targeted by Brazilian fisheries, they suffer impact similar than the target species, being among the most discarded fishes by deep bottom trawling. Trophic Ecology: Data from research surveys and commercial fishing were used to analyze the trophic ecology of four species inhabiting the upper slope of southern Brazil: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis and Lucigadus ori. For the two abundant ones, ontogenetic changes, seasonal variations, intra- and interspecific dietary overlap, parasite fauna and aspects of functional morphology are also described. C.marinii had an extremely diverse diet, preying infauna, epifauna, plankton, necton and carcasses. M.occidentalis fed on larger and nektonic prey, but also included crabs and carcasses in the diet. Both species showed ontogenetic shifts and seasonal variations in diet composition, both leading to changes in intra- and interspecific diet overlap patterns. Species showed quite distinct feeding anatomy and proportions of body with mouth size, reflecting on feeding strategies. There was little interspecific food overlap. In most cases when the diet was more similar there was a spatial segregation. The coexistence of these species appears to be facilitated by the development of different functional morphologies and feeding strategies. A considerable portion of the diet of these species is due to the consumption of carcasses of pelagic and mesopelagic organisms, and even insects, bypassing the benthic trophic web. Conservative (minimum) estimates of the mean weight of carcasses in diet ranged from 3 to 20%, increasing with the size of the predators and towards deeper waters. C.marinii showed a lower consumption of carcasses and a high proportion of mesopelagic fishes and cephalopods, however, the analysis of the feeding morphology and prey size leads to believe that most of these two groups of prey were consumed as carcasses. This source of food bypass the detritus food chains and connect the concentrations of macrourids to fluctuations in the abundance of epi and mesopelagic organisms and to oceanographic processes that increase their concentration and mortality (e.g. mesoscale anticyclonic eddies). Distribution, Biomass and Oceanography: Data from two seasonal bottom trawl surveys were used to provide information on distribution, abundances, densities, sizecomposition and biomass estimates for seven species: Coelorinchus marinii, Malacocephalus occidentalis, M. laevis, Lucigadus ori, Hymenocephalus billsam, Ventrifossa macropogon and V. mucocephalus. The total biomass was estimated in 5.5 and 8.3 kt respectively in winter-spring and summer-autumn. C.marinii and M.occidentalis comprised 98% of the biomass. For these two abundant species, surface maps were made with spawning areas, feeding index, sex and immature/mature ratios, and were related to oceanographic processes, providing insights on strategies and important processes regulating distribution and abundance patterns. Both species showed a marked seasonal variation in the extent and location of spawning areas. Most C.marinii females were mature (90%), suggesting an early maturation during pelagic phase and acquiring demersal habit just prior the onset of maturation, while M.occidentalis showed few matures females and settle to bottom well before maturity. Temperature rather than depth seems to be the main factor regulating the batimetric distribution of both species. We describe three processes responsible for distribution and abundance patterns found in these species. Differentpatterns of spatial segregation were found in both species, related with depth, sex and maturity. It is suggested that areas with high biomass Macrouridae (scavengers) are induced by zones of occurrence semi-permanent mesoscale processes (e.g. eddies). These processes increase productivity and enable large biomass of short-lived organisms found in the upper layers, and also increase the concentration, mortality and availability of carcasses, favoring scavenger predators. These processes may be responsible for inconsistencies in biomass of megafauna and macrofauna found in some studies, where biomass of megafauna was of the same order of magnitude or larger than macrofauna, contradicting the Eltonian principle. It is suggested that future studies attempt to relate mesoscale processes with the biomass of potential short-lived prey in surface waters and higher biomass of scavengers. This work highlights the importance of the study of ocean dynamics, combining biological and oceanographic observations, trying to understand the role of mesoscale physical processes on the distribution and abundance patterns of species.