In the southeastern United States, skimmer trawls, pusher-head trawls, wing nets, and small try nets (headrope length less than 12-ft (3.66-m)) are exempt from using a turtle excluder device (TED) and instead must adhere to tow time restrictions as a mode to mitigate sea turtle bycatch. However, observer and stranding data indicate that these tow times may often be exceeded and result in mortality of sea turtles. The National Marine Fisheries Service (NMFS) published a notice of proposed rulemaking in December 2016 to extend TED requirements to other trawl types, however there has been limited development of specialized TEDs for these smaller trawls. In anticipation of a regulatory change, we developed and identified multiple versions of a top-opening TED with a minimum width of 28-in (71-cm) and height of 24-in (61-cm) as the best option for small trawl gears. Prototypes were initially equipped within small try nets and tested for gear performance and sea turtle exclusion in Panama City, Florida. The final designs were then tested for target shrimp retention, bycatch reduction, and general usability of TEDs in the commercial fisheries. A paired comparison test was conducted in 8-ft (2.44-m) and 10-ft (3.05-m) try nets aboard the NMFS R/V Caretta, three commercial skimmer trawls in vesselsFarfantepenaeus duorarum) fishery. There was a general reduction of shrimp and bycatch averaging from a minimum loss of 3.31% in the Miami wing net fishery (FV FL-01) to 22.07% in the skimmer trawl fishery (FV LA-01). This dissertation research indicates that TEDs can function properly in small trawl types, however additional studies are recommended to minimize the shrimp loss and improve the overall TED effectiveness specific to each fishery and trawl type evaluated.

This thesis examines the biology, ecology and anthropogenic threats of Indo-Pacific bottlenose dolphins (Tursiops aduncus) off Zanzibar, Tanzania, based on research conducted and samples collected between 2000 and 2008. Distribution and occurrence are described based on incidental catches (bycatch) in gillnet fisheries. Biology and ecology are examined by ageing and studying the reproductive biology and stomach contents of collected specimens. The composition of organohalogen compounds is determined in blubber samples, and assessment and mitigation of bycatch are conducted using observers onboard fishing vessels. Fisheries bycatch data showed that Indo-Pacific bottlenose dolphins occur year round in all areas around Zanzibar. Sexual maturity was attained between 7 and 8 years and body length 190-200 cm in females and at 16 years and body length 213 cm in males. The gestation period was estimated to be 12.3 months, with calving occurring throughout the year, peaking November-March and with an interval of 2.7 years. The estimated pregnancy rate was between 0.10 and 0.58 depending on methods used. Stomach contents revealed a relatively large number of prey species, but that only a few small- and medium-sized neritic fish and cephalopods contribute substantially to the diet. Estimates of total annual bycatch were >9% which is not considered sustainable. An experiment showed that pingers can be a short term mitigation measure to reduce bycatch of dolphins in both drift- and bottom set gillnets. Methoxylated polybrominated diphenyl ethers (Meo-BDEs) were found at higher concentrations than anthropogenic organic pesticides (OCPs), with only traces of polychlorinated biphenyls (PCBs) detected. This study reveals the magnitude and apparent susceptibility of Indo-Pacific bottlenose dolphins off Zanzibar to anthropogenic threats, especially fisheries bycatch, and it is clear that immediate conservation and management measures are needed to reduce bycatch. / At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 2: Submitted. Paper 4: Manuscript. Paper 5: Submitted.

Abstract Because the number of sharks is decreasing , the problem has been concerned in recent years. In this paper , I conduct a research about the shark bycatch problem¡Ataking the target specie of bigeye tunas and the bycatch specie of sharks as the research objects . Initially I collect from 2000 to 2007 Atlantic bigeye tuna and shark catches datas for resource assessment.and then making comparasion with resource equilibrium values of open access fishery model and net present value maximization fishery model. it is found during the period it has showed a upward trend for bigeye tuna resources¡Abut it has not showed the bigeye tuna resources achive the optimal level. It has showed a diminishing trend for shark resources, the result shows the resources will face extinction crisis if the fishery is not controlled well. Then, doing sensitivity analysis to understand the effects of exogenous parameters to bigeye tuna and shark catches, resources and efforts. Finally, facing with the sharks bycatch problem , discussing the effect of improved fishing gears on sharks bycatch control by doing the sensitivity analysis of fishing hook cost and bycatch coefficient to shark resources and catches¡OFrom the results , it shows that no matter affecting the fishing hook cost or bycatch coefficient , the amount of shark can be reduced effectively by adopting improved fishing gears.

<p>Mismatches in the spatiotemporal variability of resource, resource users and management actions breeds inefficiency in the management of marine resources. To date, the spatiotemporal resolution and extent of fisheries management has been largely dictated by logistical and political constraints, and secondarily by the geographic range of the species or meta-population dynamics. Management units are rarely smaller than 1000 km2 in developed coastal fisheries, and management measures generally occur at resolutions larger than 100 km2. From a temporal perspective, the finest resolution of management measures is at best a month but more generally a year. As such, attempts to manage processes and patterns at sub-10 km, sub-1 month resolution often involve some level of spatiotemporal mismatch. To address the obvious spatiotemporal mismatch between a dynamic ocean and static management, to allow for a comprehensive implementation of ecosystem-based fisheries management, and to minimize inefficiency in our management of marine resources, we must seek to develop more dynamic management measures that allow managers to address scales, processes and patterns occurring under ten kilometers.</p><p>In this dissertation I apply point pattern processes, cumulative distribution functions, receiver operator characteristic curves, simulated annealing tools, regression models and clustering techniques to develop examples of two dynamic management measures and to compare the efficiency of static versus dynamic management measures. I show that autocorrelation analysis can inform the distances and times used in real-time closures based on move-on rules. Further, I identify optimum bottom temperature threshold values to separate individual species within the Northeast Multispecies Fishery from Atlantic cod. Results demonstrate that dynamic spatiotemporal management measures are widely applicable, and more effective and more efficient than static time-area closures. Unexpected trends in some results due to a changing climate indicate possible increasing thermal overlap between Atlantic cod and many other species in the fishery. Implications of scale in fisheries management and the importance of coarse scale (1 - 10km) ecological patterns to fisheries are discussed.</p> / Dissertation

Submitted by Maria Suzana Diniz (msuzanad@hotmail.com) on 2015-11-03T15:03:09Z No. of bitstreams: 1 arquivototal.pdf: 4451269 bytes, checksum: f9b87e98dd454fb08074cecc188cc469 (MD5) / Made available in DSpace on 2015-11-03T15:03:09Z (GMT). No. of bitstreams: 1 arquivototal.pdf: 4451269 bytes, checksum: f9b87e98dd454fb08074cecc188cc469 (MD5) Previous issue date: 2015-02-24 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Sea turtles have a long history of human exploitation around the world who have contributed to the population decline of the species, along with other threats, especially the accidental capture by various types of fishing. Ethnobiological research can provide important information to understand the context of exploitation / interaction of these animals to people. The research was conducted with the localized fishing communities in the Penha Beach and Estuary Mamanguape River (ERM). Data were obtained through a structured questionnaire and semi-structured and free interviews. The questionnaire elicited socioeconomic data on the fishing techniques used, the fishermen's knowledge about sea turtles, incidental capture of events involving these animals and a projective test, with illustrations of the species. Were prepared Local Ecological Knowledge Indicators (LEK) and Conservation Attitudes for fishermen. Our results show that the incidental capture of sea turtles is mainly related to gill net technique. In this technique, large nets catch more turtles accidentally. Recommendations to reduce the incidental capture and mortality of sea turtles are presented. Respondents fishermen recognize the different species of sea turtles that occur in the studied areas. The fishermen showed high ecological knowledge about sea turtles, demonstrated by high values in CEL indicator. The results show that knowledge is not evenly distributed among the fishermen of each community, there are experts in the field at each site. The Conservation Attitudes indicator showed a high predisposition to conservation in the two communities. Were also discussed food taboos, medicinal and traditional use of sea turtles. / Tartarugas marinhas tem longo histórico de exploração humana em todo o mundo, que têm contribuído para o declínio populacional das espécies, juntamente com outras ameaças, com destaque para a captura acidental por diversos tipos de pesca. Pesquisas etnobiológicas, como esta, podem fornecer informações importantes para compreender o contexto de exploração/interação desses animais com as pessoas. A pesquisa foi realizada junto às comunidades de pescadores localizadas na Praia da Penha e no Estuário do Rio Mamanguape (ERM). Os dados foram obtidos através de questionário estruturado e entrevistas semiestruturadas e livres. O questionário levantou dados socioeconômicos, sobre as técnicas de pesca utilizadas, o conhecimento dos pescadores sobre as tartarugas marinhas, eventos de captura incidental envolvendo esses animais e um teste projetivo, com ilustrações das espécies. Foram elaborados Indicadores de Conhecimento Ecológico Local (CEL) e de Atitudes de Conservação para os pescadores. Nossos resultados apontam que a captura acidental de tartarugas marinhas está relacionada principalmente à técnica de rede de espera. Nesta técnica, as redes de malha grande capturam mais tartarugas acidentalmente. São apresentadas recomendações para redução da captura incidental e mortalidade de tartarugas marinhas. Os pescadores entrevistados reconhecem as diferentes espécies de tartarugas marinhas que ocorrem nas áreas estudadas. Parte dos pescadores mostrou elevado conhecimento ecológico sobre tartarugas marinhas, demonstrado por valores elevados no Indicador de CEL. Os resultados mostram que o conhecimento não está uniformemente distribuído entre os pescadores de cada comunidade, há especialistas no assunto em cada local. O Indicador de Atitudes de Conservação mostrou uma alta predisposição para conservação nas duas comunidades. Foram discutidos ainda tabus alimentares, uso medicinal e artesanal de tartarugas marinhas.

Regarder la mer comme un espace politique et social implique de dépasser les frontières et les disciplines. L’exercice est passionnant mais nécessite de rebattre les cartes. Cette thèse a ainsi comme ambitieux objectif de comprendre comment les humains observent et gèrent l’environnement marin, et comment ils parviennent, ou non, à échanger autour des représentations ainsi obtenues. Le célèbre exemple d’Antoine de Saint-Exupéry devrait suffire à donner une idée du défi à relever. Là où certains voient un chapeau d’autres imaginent un serpent boa qui digère un éléphant ; à nous, alors, de chercher à dessiner au travers de ce travail une description à la fois simple et précise des points de vue des humains sur ce qui les entoure ; des scientifiques, des décideurs et des pêcheurs sur les interactions entre pêcheries et petits cétacés dans le golfe de Gascogne puisque c’est le sujet qui nous intéresse. Nous nous sommes donc demandé comment observer les positionnements stratégiques des acteurs sur les captures accidentelles de petits cétacés dans le Golfe de Gascogne pour rétablir des relations de confiance et de dialogue entre les acteurs ? Pour répondre à cette problématique, nous avons mis en place un processus participatif d’accompagnement des acteurs pour construire une vision partagée de l’environnement marin. A l’aide de cette méthode, nous avons montré que l’environnement marin est un construit scientifique et qu’il est nécessaire de le construire politiquement et socialement pour y intégrer la complexité nécessaire à une gestion réellement durable des interactions entre activités humaines et écosystème marin. A ce titre, les instruments d’observation et de gestion de l’environnement jouent un rôle central comme nous l’expliquerons dans le cadre de cette thèse. / Looking at the sea as political and social space involves reaching across borders and disciplines. The task is thrilling but requires reshuffling the cards. Thus, this thesis ambitious objective is to understand how humans observe and manage the marine environment, and how they achieve, or not, to exchange around the obtained representations. The famous example of Antoine de Saint-Exupéry should give us an idea of the challenges to overcome. Where some see a hat, others imagine a boa snake digesting an elephant. So, in this study, our job is to draw a simple but precise description of humans’ points of view on their surroundings. More precisely, we focus on scientists, decision-makers and fishermen’s points of view on interactions between fisheries and small cetaceans in the Bay of Biscay (France). Therefore, we wondered how to observe stakeholders’ strategic positions on small cetacean bycatch in the Bay of Biscay to restore trust-based relationships and re-establish constructive dialogue among stakeholders. To answer this question, we set up a participatory process to support stakeholders in building a shared vision of the marine environment. By implementing this method, we showed that the marine environment is scientifically constructed. It also needs to be politically and socially constructed to incorporate the necessary complexity to sustainably manage interactions between human activities and marine ecosystems. As such, observation and management instruments of the marine environment play a central role as we will explain in this thesis.

Horseshoe crabs (Limulus polyphemus) have been harvested along the east coast of the United States since the 1800s, however a Fishery Management Plan (FMP) was only recently created for this species. To date, there have not been any studies that have attempted to identify or quantify bycatch in the horseshoe crab trawl fishery. A horseshoe crab trawl survey was started in 2001 to collect data on the relative abundance, distribution, and population demographics of horseshoe crabs along the Atlantic coast of the United States. In the present study, species composition data were collected at sites sampled by the horseshoe crab trawl survey in 2005 and 2006. Seventy-six different taxa were identified as potential bycatch in the horseshoe crab trawl fishery. Non-metric multidimensional scaling (NMS) was used to cluster sites and identify the spatial distribution of taxa. Sites strongly clustered into distinct groups, suggesting that species composition changes spatially and seasonally. Species composition shifted between northern and southern sites. Location and bottom water temperature explain most of the variation in species composition. These results provide a list of species that are susceptible to this specific trawl gear and describe their distribution during fall months throughout the study area. Identifying these species and describing their distribution is a first step to understanding the ecosystem-level effects of the horseshoe crab trawl fishery. / Master of Science

Incidental catch, or bycatch, of harbour porpoise (Phocoena phocoena) in fishing operations is an international conservation issue. The main objective of this thesis was to develop methods for determining the impact of bycatch on the state and dynamics of porpoise populations and for calculating bycatch limits that will achieve conservation objectives in the future. I applied these methods to the North Sea as a case study. First, I analysed sighting rates of harbour porpoise on seabird surveys in the North Sea during 1980-2003 to determine whether these data could provide informative time-series of relative abundance. Some general patterns and trends in sighting rates were consistent with previous studies. However, the standardised indices of abundance were relatively imprecise and thus have limited value for a monitoring framework that relies on statistical detection of trends. Second, I used a population model to integrate available data on harbour porpoise in the North Sea and to assess the dynamics of the population during 1987-2005. There was a high probability that bycatch resulted in a decrease in abundance. The estimated life history parameters suggested a limited scope for population growth even in the absence of bycatch. The model and data were not informative about maximum population growth rate or carrying capacity. The model suggested that dispersal was the most plausible explanation for observed changes in distribution within the North Sea. Third, I considered management procedures for calculating bycatch limits. I performed simulations to compare the behaviour of the procedures, to tune the procedures to specific conservation objectives and to test the robustness of the procedures to a range of uncertainties regarding population dynamics and structure, the environment, observation and implementation. Preliminary annual bycatch limits for harbour porpoise in the North Sea ranged from 187-1685 depending on the procedure, tuning and management areas used.

Dentro do contexto de crise global pesqueira que afeta tanto a pesca industrial quanto a artesanal, este trabalho visa descrever e analisar a pesca artesanal de emalhe no sul do Brasil, além de estudar a interação entre essa pesca artesanal e as tartarugas marinhas. O capítulo 1 consiste na caracterização social, econômica e operacional da pesca artesanal, avaliando o esforço pesqueiro de suas diferentes modalidades. A análise dos dados fornecidos por pescadores revelou a diferenciação na captura e esforço entre dois grupos de embarcações: barcos até 12,5 metros de comprimento total e barcos acima de 12,5 metros. As entrevistas também geraram uma ilustração que demonstra a sobreposição da área de atuação dos pescadores. Neste capítulo são propostas medidas de gestão da pesca artesanal de emalhe que consideram o rendimento dos pescadores e preservam os recursos pesqueiros. No capítulo 2 foram analisados fatores sociais e operacionais da pesca relacionados à captura incidental de tartarugas marinhas. Entrevistas com pescadores (n=92) e desembarques monitorados pelos pescadores (n=320) registrados em locais de pesca dentro e fora de Unidades de Conservação Marinhas no Rio Grande do Sul e Santa Catarina verificaram a influência do manejo espacial sobre as capturas incidentais. Analisou-se também o conhecimento ecológico local (CEL) dos pescadores sobre as tartarugas marinhas. A criação de zonas exclusivas para a pesca artesanal e o aumento de vistorias às redes de pesca são propostas para reduzir as capturas incidentais pela pesca artesanal de emalhe no sul do Brasil, através do envolvimento dos pescadores nas pesquisas e do co-manejo dos recursos pesqueiros. / Within the context of global fishing crisis that affects both industrial and artisanal fisheries, this survey aims to describe and analyze the artisanal gillnet fishery in southern Brazil and study the interaction between this fishing and sea turtles. The chapter 1 consists in social, economic and operational characterization of artisanal fisheries, assessing the fishing effort of different kinds of fisheries. The analysis of data provided by fishermen revealed the differentiation in catch and effort between two vessel’s groups: boats up to 12.5 meters long and boats over 12.5 meters. The interviews also show the spatial overlap of areas of operation of fishers. In this chapter we proposed measures for the management of small-scale gillnet fishing that consider the income of fishermen and preserve fish stocks. In chapter 2 we analyzed social and operational fishing factors related to bycatch of sea turtles. Interviews (n=92) and landings (n=320) recorded in fishing grounds inside and outside of Marine Protected Areas in Rio Grande do Sul and Santa Catarina assessed the influence of the spatial management on bycatch. It analyzed also the local ecological knowledge (LEK) of fishers about sea turtles. The creation of exclusive zones for artisanal fishing and to increase inspections of fishing nets are presented to reduce incidental catches by artisanal gillnet fishing in southern Brazil, such as the involvement of fishermen in research and co-management of resources.

Le plan de restauration des tortues marines aux Antilles françaises a été validé par le Conseil National pour la Conservation de la Nature en 2006. Les captures accidentelles dans les filets de fond, i.e. les trémail, folle et filet droit, sur le plateau continental constituent la principale menace. Des filets faisant varier la hauteur, le maillage et l’inclinaison ont été comparés à des filets professionnels au cours de 226 pêches expérimentales. Le trémail est peu sélectif. Des filets à profil bas permettent d’obtenir des rendements comparables et réduiraient les captures de tortues. Les captures accidentelles sont plus abondantes dans les trémails et les folles. Les pêches à longs temps de calée provoquent plus de 90% de taux de mortalité de tortues et augmentent les quantités de rejets. Près de deux milliers de tortues seraient capturées chaque année aux Antilles françaises, avec une mortalité avoisinant les 60%. Les tortues adultes pêchées l’ont été en période de nidification et les tortues dites résidentes sont dans la grande majorité des juvéniles ou sub-adultes, cause de la surexploitation locale passée et signe de populations non stables. La menace « pêche » est d’autant plus importante qu’elle touche les femelles nidifiantes, meilleurs espoirs de rétablissement des stocks. En étroite collaboration participative avec les professionnels de la mer, la protection des tortues et des ressources marines passerait par une réduction de la hauteur des filets et de leurs temps de calée et l’interdiction totale ou partielle de ceux à mailles larges. / The national marine turtles recovery plan in FWI was adopted in 2006 by the National council for the nature conservancy. The bottom nets bycatch, i.e. the trammel, folle and gill nets, on the continental shelf are the main threat. Experimental nets with different heights, meshing and incline was compared to professional ones during 226 experimental trials. Trammel net is non selective. Low profile nets maintain a similar productivity and reduce the turtle bycatch. Trammel and folle nets cause more bycatch. The long soak times lead to more than 90 % of turtles mortality and more discards. Each year, about two thousands of turtles would be captured in FWI, with a mortality rate closed to 60 %. The mature turtles were captured during the nesting season and the resident ones are mostly juveniles or sub-adults, because of the local past overexploitation and indicator of non stable populations. The “fishery” threat is particularly important it affect nesting females, best stocks recovery hope. Closely to the marine professionals, the marine turtle and resources protection would be effective thanks to the reduction of the height and soak times nets and the total or partial ban of large meshing size nets.