Animal populations are limited by their environment and interactions with one another, the latter proportional to density. How density-dependent mechanisms regulate populations is poorly understood, particularly for migratory animals. Winter, or non-breeding, mechanisms remain particularly poorly understood for almost all migratory bird species. This dissertation tested the hypothesis that American Redstarts (Setophaga ruticilla) are regulated both within and between habitats in the winter by two mechanisms, a crowding effect and a buffer effect. As population size increases, crowding increases competition for space and resources and more individuals are relegated to lower quality habitats and forced into a transient behavioral strategy, which buffers high quality habitats from negative feedback of density. My study was carried out in Jamaica, where redstarts occupy diverse habitats. I found that population size varied among habitats, but accounting for both territorial and transient individuals was critical for accurate assessment of this variation. Ecological conditions drive differences in habitat suitability and redstart density at multiple spatial scales. Regionally, redstart survival, density, and numbers of transient individuals distinguish inland from coastal populations, consistent with differences in ecological conditions (e.g. rainfall). Locally, timing of spring departure, as well as age and sex structure distinguish neighboring habitats, consistent with increased competition for food. When population size increased over the years of this study, changes in local density were similar among habitats, and thus not the result of a buffer effect. However, increasing densities decreased food availability, which corresponded with negative feedback on departure timing and territorial behavior, i.e. more transients, in poorer habitats. This supported a crowding effect on spatial behavior (territoriality) and late-winter condition of individuals relegated to low suitability habitats. High quality inland habitats appear to buffer individuals from the effects of changing population abundance, as well as ecological conditions, evidence of a regional buffer effect. / acase@tulane.edu

Submitted by Valquíria Barbieri (kikibarbi@hotmail.com) on 2018-04-10T19:32:13Z No. of bitstreams: 1 DISS_2014_Gabriela Maria Maimone de Figueiredo.pdf: 941864 bytes, checksum: 484a34af643f773276e576c7baaae016 (MD5) / Approved for entry into archive by Jordan (jordanbiblio@gmail.com) on 2018-04-26T17:22:46Z (GMT) No. of bitstreams: 1 DISS_2014_Gabriela Maria Maimone de Figueiredo.pdf: 941864 bytes, checksum: 484a34af643f773276e576c7baaae016 (MD5) / Made available in DSpace on 2018-04-26T17:22:46Z (GMT). No. of bitstreams: 1 DISS_2014_Gabriela Maria Maimone de Figueiredo.pdf: 941864 bytes, checksum: 484a34af643f773276e576c7baaae016 (MD5) Previous issue date: 2014-03-17 / CNPq / Este estudo teve como objetivo avaliar a distribuição espacial e temporal das assembleias do ictioplâncton do rio Cuiabá e áreas adjacentes, no período de novembro de 2007 a fevereiro de 2008, bem como estudar as relações de densidades dos ovos e larvas com os fatores locais físicos (temperatura, velocidade da água) químicos (fosfato, nitrogênio total, nitrogênio amoniacal), como indicadores da produtividade no ambiente, fatores bióticos (densidades de fitoplâncton e zooplâncton) e com os fatores regionais (nível do rio e pluviosidade), formando condições e locais favoráveis para seu desenvolvimento e sobrevivência nos estágios iniciais de vida dos peixes. As coletas do ictioplâncton foram realizadas em 14 pontos ao longo do rio e áreas adjacentes, com arrastos sub-superficiais de 20 e 40 cm de profundidade, com rede tipo cilindro-cônica de malha 300 μm. Concomitantemente, foram coletadas amostras de fitoplâncton e zooplâncton, bem como realizadas as medidas das variáveis locais e regionais. Após as coletas as amostras foram triadas e identificadas ao menor nível taxonômico possível. Para avaliar as diferenças nas densidades de ovos e larvas nos locais e nos meses de estudo, foi utilizado o teste de ANOVA por medidas repetidas. Foi utilizada uma correlação de Spearman para a análise das densidades de ovos e larvas com as variáveis regionais e com as variáveis locais. Para avaliar as densidades das larvas com as densidades do fitoplâncton e do zooplâncton também foi utilizada a correlação de Spearman, porém, este teste foi feito com as larvas que foram identificadas em nível de gênero e espécie, e posteriormente, com cada espécie de larva de peixe migrador. Para analisar a composição das estruturas das assembleias de larvas através das densidades nos locais foi utilizado o teste de Mantel parcial, entre as distâncias de similaridades, distâncias ambientais e geográficas. Para avaliar a diferença temporal entre os grupos de Characiformes e Siluriformes foi feito o teste de ANOVA por medidas repetidas. Foi realizada uma ordenação direta das densidades das larvas dos migradores nos pontos amostrais. Os resultados espaciais com as densidades de ovos (F1;10= 0,572; p=0,467), e larvas (F1;10= 3,494 ; p=0,091) não foram significativos. Os resultados temporais com as densidades de ovos (F3;30= 0,533; p=0,663) não foram significativos, já para as larvas (F3;30= 4,539; p=0,009) foram significativos, com picos de densidades em novembro e janeiro. Houve correlação significativa entre as densidades das larvas com o nitrogênio total (r=-0,127; p=0,025) e a temperatura da água (r=0,292; p=0,035). O teste de Mantel parcial mostrou que a variação ambiental não foi fator determinante na distribuição da composição taxonômica dos grupos ao longo do rio (r=-0,214; p=0,966) e que as assembleias de larvas apresentam significativa dependência geográfica (r=0,459; p=0,001), quanto mais próximos os pontos geograficamente, mais similares foram as composições taxonômicas. Os resultados taxonômicos mostraram diferença temporal significativa (F3;48= 3,994; p=0,012) entre os grupos dos Siluriformes e Characiformes. / The aim of this study is to assess the spatial and temporal distribution of Ichthyoplankton assemblies of the Cuiabá River and adjacent areas, from November 2007 to February 2008. We also studied the relationships of egg and larvae density with local physical factors (temperature, water velocity) chemical (phosphate, total nitrogen, ammoniac nitrogen) as indicators of productivity in the environment, abiotic factors (densities of phytoplankton and zooplankton), and with regional factors (the river level and rainfall), as they form favorable conditions and locations for their development and survival in the earlier stages of fish life. Ichthyoplankton samples were conducted in 14 points along the river, with subsurface water of 20 and 40 cm deep, with cylinder-type nets of 300 μm. Concomitantly, were collected samples of phytoplankton and zooplankton, and measured the local and regional variables. After the data collecting, the samples were sorted out and identified to the lowest taxonomic level possible. To evaluate differences in densities of eggs and larvae in the localities and in the months of study, ANOVA for repeated measurements was applied. Spearman correlation was used for the analysis of densities of eggs and larvae with regional and local variables. To evaluate larval densities with densities of phytoplankton and zooplankton we also used the Spearman correlation, however, this test was done with larvae that were identified at the level of genus and species, and later, with each species of migrating fish larvae. To analyze the composition of the structure of assemblies of larvae through the densities at the localities, we applied the partial Mantel test, between the distances of similarities, environmental and geographic distances. To evaluate the temporal difference between the groups of Characiformes and Siluriformes, we applied an ANOVA for repeated measurements. A direct ordering of the migratory larvae densities in sampling points was done. The spatial results with egg densities (F1;10= 0,572; p=0,467), and larvae (F1;10= 3,494 ; p=0,091) were not significant. Temporal results with egg densities (F3;30= 0,533; p=0,663) were not significant, however for the larvae (F3;30= 4,539; p=0,009) the results were significant with peaks in November and January. There was a significant correlation between larval densities and total nitrogen (r=-0,127; p=0,025) and the water temperature (r=0,292; p=0,035). The partial Mantel test has shown that the environmental variation was not a determining factor in the distribution of the taxonomic composition of groups along the basin (r=-0,214; p=0,966). The larvae assemblies show significant geographic dependence (r=0,459; p=0,001), the closer the dots geographically, the more similar were the taxonomic compositions. Taxonomic results show significant temporal difference (F3;48= 3,994; p=0,012) between groups of Siluriformes and Characiformes.

Commercial pelagic longline fishers within the U.S. Atlantic, Gulf of Mexico, and Caribbean are required to report all fishing interactions per each gear deployment to NOAA’s Vessel Logbook Program of the Southeast Fisheries Science Center to quantify bycatch, increase conservation efforts, and avoid jeopardizing the existence of vulnerable species listed under the Endangered Species Act (ESA). To provide additional accuracy, the Pelagic Observer Program (POP) of the SEFSC deploys professionally trained observers on longline vessels to produce a statistically reliable subset of longline fisheries data. A comparison of self-reported (“unobserved”) datasets versus observer-collected (“observed”) datasets showed a general consistency for most target species but non-reporting or under-reporting for a number of bycatch species and “lesser-valued” target species. These discrepancies between catch compositions and abundancies regarding targeted species, species of bycatch concern, and species of minimum economic value can provide insight into increased fisheries regulations, stricter requirements, or additional observer coverage.

Onze espèces de mammifères marins vivent toute l’année en Arctique et dépendent de ce milieu marin si particulier. Ces espèces endémiques et uniques au monde se déplacent à grande échelle en traversant plusieurs zones maritimes des huit États côtiers et la haute mer. Toutefois, leurs conditions de vie sont menacées par les effets des changements climatiques et l’accroissement des activités humaines dans la région. Bien qu’il existe des règles juridiques de protection au niveau national, le phénomène de « déplacement » affaiblit leur efficacité. En effet, les mammifères marins ne connaissent pas les délimitations maritimes et sont donc assujettis à des protections variables et potentiellement incohérentes. Il est ainsi nécessaire de trouver une stratégie pour harmoniser les règles nationales et développer de nouvelles normes pour leur protection. L’objectif de ce mémoire est de découvrir si le droit international assure une protection adéquate aux mammifères marins qui se déplacent en Arctique. Cette étude identifie et analyse les forces et les faiblesses de plusieurs instruments juridiquement contraignants et de soft law au contenu général et spécifique. Bien qu’il n’existe aucun texte qui traite des mammifères marins en Arctique purement et simplement, ces instruments juridiques protègent certaines espèces de mammifères marins et certaines parties de la région Arctique. Pourtant, les onze mammifères marins connaissent les mêmes enjeux et forment un tout interdépendant. Les conclusions indiquent d’adopter une approche intégrée et d’opter pour une meilleure collaboration entre les États côtiers qui sont les mieux placés pour protéger ces espèces qui se déplacent en Arctique. / Eleven species of marine mammals live year-around in the Arctic and are dependent on its distinctive marine environment. These unique endemic species, which travel long distances, traverse the different maritime zones of the eight coastal States and cross into the high seas. However, their living conditions and habitats are under threat because of climate change and the expansion of human activity in the region. Although the coastal States have all adopted national legislation and regulations for the protection of marine mammals, the fact of their large scale “movement” weakens the efficacy of those laws. Indeed, marine mammals are the subject of various and potentially inconsistent domestic protections. For this reason, it is necessary to develop strategies to harmonise national measures and to devise new norms of protection. The objective of this thesis is to discover whether international law offers adequate protection to marine mammals that roam across the Arctic region. This study identifies and analyses the strengths and the weaknesses of a number of legally binding and soft law instruments of both a general and specialised nature. Many of the legal instruments target specific Arctic marine mammals or distinct areas of the Arctic region for protection. Yet, the eleven species at the heart of this enquiry are all experiencing the same difficulties and constitute an interconnected whole. The findings herein indicate the need for an integrative approach and for increased cooperation among the Arctic coastal States who are in a unique position to protect these species that roam throughout the Arctic.

2005年「大西洋鮪類資源保育委員會」(International Commission for the Conservation of Atlantic Tunas, ICCAT)第十九屆年會將台灣2006年在大西洋大目鮪(Bigeye Tuna)的漁獲配額自14,900公噸削減為4,600公噸的決定，即05-02號建議(Recommendation by ICCAT Regarding Control of Chinese Taipei’s Atlantic Bigeye Tuna Fishery [05-02] in 2005)，除反應出漁業資源日益稀少和各國竸爭激烈的事實外，也顯示了國人海洋漁業生態保育的觀念有待加強。 / 本論文乃以ICCAT 05-02號建議作為個案研究，對高度洄游魚類種群(highly migratory species)之養護與管理體系為一整體檢視，探討該號建議所呈現之生態保育問題。內容側重於法規範面之探討，並就高度洄游魚類種群之定義、生態習性、種類、及資源使用狀況為一基本介紹。主要探討三大議題：(1)國際規範體系架構；(2)養護與管理高度洄游魚類之現況；(3)當前面臨之問題與挑戰。 / 全球海洋資源面臨的人為挑戰模式均同，本文焦點雖在高度洄游魚類種群之探討，但也反應出其他種類漁資源在保育上所面臨的共同問題，只不過因高度洄游魚類生態上的特殊性，使其整體養護與管理過程更能突顯出國際漁業治理的本質─國際合作的必要性。但若從另一角度分析漁業管理制度發生改變的原因，則將突顯出國際漁業治理的另一項本質，即國家利益的追求，事實上這也是所有國際活動的基本特徵。因此，以專業性的角度來分析區域漁業組織運作的同時，不能忽略國際政治因素的牽絆，國家漁業經濟利益透過國際政治上的實力對比在區域漁業組織的運作過程中彰顯出來。 / 本論文章節安排分為六章，首先概略介紹「高度洄游魚類」之意義、特性及資源使用狀態(第一章)，爾後簡介現行有關高度洄游魚類之國際規範體系(第二章)，接著以ICCAT為案例，使讀者明白當前國際間透過區域漁業組織來施行漁資源管理的實際運作情形(第三章)，透過05-02號建議讓讀者了解區域漁業組織如何敦促成員國遵守區域漁業規範，落實其養護與管理高度洄游魚類之國際任務(第四章)，並探討ICCAT05-02號建議所反應出來的制度面或執行面之問題(第五章)。最後綜合各章節內容，針對高度洄游魚類之整體規範體系架構為一觀察反省，歸結出本議題核心所在，即追求國家利益前提下的國際合作(第六章)。 / 國際間對於高度洄游魚類種群的保育工程已然啟動，國家願意讓渡出更多一些的權力由國際專門性機構來主導，並在一定規範架構下進行國際合作，這是值得肯定的發展趨勢，並可觀樂期待國際間對於生態環境議題將給予更多的關注，落實資源永續經營的理念。 / On 19th regular meeting of the International Commission for the Conservation of Atlantic Tunas (ICCAT), the commission decided to cut down Taiwan’s quota of Bigeye tuna in Atlantic Ocean form 14,900 tonnage to 4,900, that is Recommendation by ICCAT Regarding Control of Chinese Taipei’s Atlantic Bigeye Tuna Fishery [05-02] in 2005. This case reflects the fact that fishery resource is coming shorter and States compete harshly. It shows that our concept of conservation ecology leaves much space to improve as well. / This thesis is a case study based on Recommendation 05-02 by ICCAT. Here try to inspect thoroughly the conservation and management system of highly migratory species, so as to discuss the problems of eco-conservation reflecting from that Recommendation. Contexts focus on the regulation aspect, and briefly introduce the definition, ecologic habitual behavior, kinds, and condition of resource consumption of highly migratory species. The three main topics to discuss are: (1) international regulation framework; (2) current status of conservation and management of highly migratory species; (3) the problems and challenges confront with nowadays. / The challenges to ocean resource caused by human activity are all the same. This thesis is about highly migratory species, but also reflects the common problem of other fish species in ecological protection respect. Merely because of the ecological particularity, the whole process of conservation and management of highly migratory species could better show the key ingredient of international fishery governance, which is international cooperation. From the other angle, the change of fishery management system mirrors the nature of international fishery management, that is pursuing of national interest. Actually, the later is fundamental character of all kinds of international interaction. Therefore, when analyzing the function of regional fishery organization, we could not ignore the international political fact. National economic fishery interest manifests through relative international political power in fishery management organizations. / There are six chapters in this thesis. First, to take a quick glance at what “highly migratory species” is and its character and resource status (chapter 1). And then turn to the introduction of current international regulation system of highly migratory species (chapter 2). Following is a case study based on ICCAT, to inform readers how Regional Fishery Organizations function actually (chapter 3). Through Recommendation 05-02 by ICCAT, we could take a look how Regional Fishery Organizations urge States to meet their commission of conserving and managing highly migratory species (chapter 4). And then go to a discussion of institutional and enforcement problems reflect from Recommendation 05-02 by ICCAT (chapter 5). Finally, we take a entirely observation and introspection from the foregoing chapters, and then sum up the core of the international fishery issue, that is international cooperation with a prerequisite of chasing national interest(chapter 6). / The international conservation of highly migratory species has set out. States are willing to transfer more competence to specialized institution and undertake international cooperation under a certain regulatory framework. This situation deserves much applause. We could look forward that international society would pay more attention to environmental ecological issues to carrying out the idea of sustainable development and management of ocean resource.