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Thesis (M.M.P.)--University of Delaware, 2008. / Principal faculty advisor: Lee G. Anderson, College of Marine & Earth Studies. Includes bibliographical references.

The grey mullet have been regarded as the treasure, so it is the very precious fishery resource in Taiwan. However, from the historic catches, it showed the amount of the grey mullet is decreasing every year and the reasons are not only influenced by the climate change, but also the catches from the vessels of PRC. The main purpose of the study is the effects of the implementation on individual transferable quota of the cross-strait in grey mullet to the living of fishers in Taiwan. Through the management of quota, it would prevent the phenomenon of biological overfishing and economic overfishing, and achieve the sustainable development of fishery resources. The article is to study about the effect of the restrictions on the purchase of unit quota and different quota ceiling to the both of buyers and sellers. The results showed that when the restrictions on the purchase of the unit quota, this would may have the amount of vessels cut to the half and prevent the economic overfishing. Because of quota trading, this will make the fishers are willing to exit the fishery and to achieve the purpose of the management of ITQ.

Abstract Taiwan is surrounded by the ocean with enriched marine eco-diversity and coastal terrains, making it a land of abundant fishery resources. Yet, after Taiwan was returned to ROC in 1945, the abuse of inshore fishery due to economical development resulted in overfishing. Under the development of industrialization, marine pollution and the use of destructive fishing gear have also caused a great damage to the ecological and biological diversities along the inshore to the drastic decrease in fisheries. Thus, how the government may find a balance between sustainability in fishery resources and economical development in local fishing communities is the major interest of this study. The present research conducts the work through the collection of annual fishing statistics and the questionnaire survey of local fishermen and government administrators. This study analyzes the changing trends of inshore fishery in Taiwan and investigates the effectiveness of current fishery regulations and the policy of fishing transformation along the inshore in Taiwan. The fisheries administration is currently adapting several fishery regulatory measures which include fishery licenses, replacement of boats and fishing vessels, and suspension of fishing activities / fishing moratorium for the management of fishery resources. Yet the fishery resources are still shrinking each year. It is obvious that those measures are ineffective on slowing down the speedy drop of fishery resources. The survey results showed that the effective administrative efforts should involve the regulation policy on fishing gears, fishing methods, fishing zones, and fishing seasons. A top-down fishery management system should be integrated with the bottom-up fishermen¡¦s autonomy, in order to establish a feasible coordination system between fishermen and the administration. In the long term, in addition to the management of some target fishes, it is important to integrate the fishery policy and management with the sustainable management of the living environment and ecosystem. These should include the assigning fishery preservation areas and the protection of the marine habitats to ensure biological diversity and to maintain the sustainable fishery resources. To reduce the fishing impact on fishery resources involving buy out the additional fishing boats, the government should actively help fishermen on their career reform. The government should also encourage the conversion of overcapacity fishing boats to the entertainment fishery. Yet through questionnaires and interviews, this study has found that most fishermen are reluctant to change their career owing to the lack of specialties and the high cost of boat remodeling. This study suggests that marine tourist vessels and whale-watching boats should be categorized as entertainment boats under the jurisdiction of the Ministry of Communication. Yet, small fishing-entertainment boats are mainly for marine fishing, or watching traditional fishing / net caging operations, and tourist diving that all operate during the off-seasons. For this, the government should provide various fishing trainings, improve the harbor facilities for entertainment fishery, and cultivate all citizens¡¦ feelings of love for the ocean to promote the marine tour vacationing and the entertainment fishery. In the coastal 200 nautical miles exclusive fisheries zone, involving fishery habitat and reproduction ground, is the sovereign right control area of every coastal country. Thus, the government is entitled to decide the optimum fishery utilization independently as the basis of the fishery development for the food security, environment and resources conservation, and fishing community social stability. The present work concludes that government should plan and establish strategies for an effective management on the inshore fishery to ensure a sustainable fishery development.

Thesis (Ph. D.)--University of California, San Diego, 2007. / Title from first page of PDF file (viewed January 9, 2008). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references.

Knowledge of many life history parameters are essential to properly assess and manage fish species. Although the snowy grouper, Epinephelus niveatus, is a commercially valuable fish, which is harvested throughout the Gulf of Mexico, little is known about its age, growth, and reproduction from this region. In this study, snowy grouper from the northern and eastern regions of the Gulf of Mexico were examined primarily using commercially-derived samples that were collected between 1984 and 2004. A total of 1,200 snowy grouper with fork lengths between 242 and 1,190 mm were collected. Sectioned saggital otoliths were used to determine the age of 774 specimens which varied from 1 to 44 years, considerably older than previously recorded. Ninety gonad samples were histologically examined; the sample population consisted of 82 females in various stages of development, 3 males, and 5 transitional fish. Female fish had ages that ranged between 3 to 14 years, with fork lengths from 330 to 880 mm and male fish had ages that were between 17 to 25 years in age, with fork lengths from 955 to 1,080 mm. Transitional fish had ages from 6 to 13 years, with fork lengths from 474 to 930 mm. The results of this study suggest that sexual maturity in females was reached around five or six years, and transition in some fish occurred as early as five years but was observed in older fish. The few males that were collected were older and larger than those fish identified as females. Snowy grouper grow slowly but consistently throughout the first 15 years or up to approximately 1,000 mm in length, at which point growth slows. The von Bertalanffy growth model fitted to all the observed data was L(t) = 1,057 * (1-e-0.0939(t+2.5375)). Snowy grouper recruit into the fishery at around age two, approximately 300 mm fork length. The truncated nature of the age distribution and low number of males collected suggest that snowy grouper in the Gulf of Mexico are likely experiencing overfishing, and more research on the species is necessary to facilitate proper management and conservation.

Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2017-02-16T13:34:08Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) OsmanCrespo_Dissertação_PPGO.pdf: 2113471 bytes, checksum: adc84d0652f9664545cb0bdac4dae2cf (MD5) / Made available in DSpace on 2017-02-16T13:34:08Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) OsmanCrespo_Dissertação_PPGO.pdf: 2113471 bytes, checksum: adc84d0652f9664545cb0bdac4dae2cf (MD5) Previous issue date: 2016-06-27 / CAPES / O agulhão negro (Makaira nigricans) é uma espécie dentre os grandes peixes pelágicos que compõe o topo da teia trófica marinha, sendo sua preservação importante para a manutenção da dinâmica populacional desses ecossistemas. Esta espécie é uma das mais procuradas pela pesca esportiva no mundo, sendo, porém, alvo de sobrepesca devido sua captura frequente como fauna acompanhante na pesca de espinhel pelágico no oceano Atlântico. O objetivo do presente trabalho de pesquisa foi compreender os movimentos migratórios, a influência de fatores ambientais em padrões de movimento e utilização de habitat pelos agulhões-negro no oceano Atlântico Sul e como essa espécie interage com o aparelho de pesca. Para o levantamento de dados sobre a utilização de habitat foram utilizadas marcas PSATs (pop-up satellite archival tags) para monitorar o comportamento do animal registrando um fluxo quase contínuo de parâmetros ambientais especificados (temperatura, pressão [profundidade] e luminosidade), onde os dados são arquivados e transmitem a informação via satélite após se desconectarem do animal. Além disso, foram também analisadas as profundidades de atuação dos anzóis do espinhel na pesca comercial de atuns e afins no Atlântico Sul, para melhor compreender quanto o esforço de pesca atualmente empregado se sobrepõe ao habitat utilizado pelos agulhões. O deslocamento horizontal durante o período de marcação variou de 374 a 1.838 km. Os resultados mostraram que os indivíduos maiores (>195 cm), considerados adultos, apresentaram deslocamentos direcionais segundo a estatística circular aplicada, enquanto que indivíduos juvenis ou menores (<195 cm) apresentaram deslocamentos considerados loopings ou sem direcionamento definido. Os dados de tempo em profundidade nos mostraram que a os indivíduos passam a maior porcentagem do tempo em águas superficiais acima dos 20m durante os períodos noturno e diurno. Os agulhões negros permaneceram a maioria do tempo dentro de uma curta faixa de temperatura, com uma média de 57% do tempo em temperaturas entre 26º e 28ºC. Os resultados quanto a sobreposição de habitat à espinhéis pelágicos nos mostrou uma relação de 59% da área rastreada sobreposta às armadilhas de pesca. A média de profundidade dos anzóis registrada foi de 49 m, sendo 90% da distribuição de profundidade dos anzóis entre 3271m. Essa distribuição vertical quando sobreposta ao padrão de utilização vertical do habitat pelos agulhões, revelou uma sobreposição que varia entre 11% e 35% durante o período diurno e 21% e 34% durante a noite. Os resultados obtidos na presente pesquisa são relevantes para uma melhor compreensão da biologia e ecologia dos agulhões negros no oceano Atlântico Sul, compondo um importante conhecimento sobre o comportamento da espécie e auxiliando para tomada de decisões e medidas de manejo e conservação da espécie a nível internacional. / Blue marlin (Makaira nigricans) is a species among great pelagic fishes that occupy the top of marine food web, being its conservation important to the maintenance of ecosystem population dynamics. Atlantic blue marlin is one of the favorite species targeted by recreational fishing in the Atlantic Ocean, however being overexploited because of its frequent capture as bycatch by commercial pelagic longline fishery. The main goal of this study was to understand migratory movement and the influence of environmental factors in movement patterns and habitat utilization by blue marlins in the South Atlantic Ocean and how this species interacts with pelagic longline gear. Pop up archival tags (PSATs) were used to collect habitat utilization data monitoring animal behavior through continuous records of specified environmental parameters (temperature, pressure [depth] and luminosity), transmitting such reports via satellite after pop-off. Furthermore, was also analyzed longline gears hook depths from commercial fisheries in South Atlantic to better understand how this fishing effort overlap to marlins habitat utilization. PSATs were programmed to record depth, temperature, and light intensity for a period of 180 days until release. The horizontal net displacement for all blue marlins ranged from 374 to 1.838 km. Results presented that larger individuals (>196 cm), considered adults, achieved directional movements according to circular statistics applied, while shorter individuals (<195 cm) presented displacement as looping or nondirectional. Time-at-depth histograms of blue marlin habitat utilization show that most individuals across all areas spent the majority of their time in shallow waters, above 20m, both during the day and night periods. Blue marlins spent most of their time within a relatively narrow temperature range, staying an average of 57% of their time in temperatures between 26° and 28°C. Overall, blue marlins had approximately 59% of their tracked range overlapped by the longline fishing gear. The average hook depth across all areas was 49 m with 90% percentile depth distribution of the hooks depth between 32-71 m. When this distribution was overlapped with the species vertical habitat utilization, the overlap ranged between 11 and 35% during daytime and 21 and 34% during nighttime. The results achieved in this study are relevant to better understand the biology and ecology of Atlantic blue marlins, composing an important knowledge about species behavior, which reduces current uncertainties about its biology and help to making decisions and take international conservation and management measures to the species.

Submitted by Anaclaudia Mattos Villalba (anaclaudiamattosvillalba@gmail.com) on 2016-04-09T22:49:54Z No. of bitstreams: 1 youblisher.com-1121544-Disserta_o_Paulo_Roberto_Santos_dos_Santos.pdf: 1064090 bytes, checksum: eedf7bfcf7e22c42250917e5321c9714 (MD5) / Approved for entry into archive by cleuza maria medina dos santos (cleuzamai@yahoo.com.br) on 2016-04-21T02:08:25Z (GMT) No. of bitstreams: 1 youblisher.com-1121544-Disserta_o_Paulo_Roberto_Santos_dos_Santos.pdf: 1064090 bytes, checksum: eedf7bfcf7e22c42250917e5321c9714 (MD5) / Made available in DSpace on 2016-04-21T02:08:25Z (GMT). No. of bitstreams: 1 youblisher.com-1121544-Disserta_o_Paulo_Roberto_Santos_dos_Santos.pdf: 1064090 bytes, checksum: eedf7bfcf7e22c42250917e5321c9714 (MD5) Previous issue date: 2015 / O aumento na abundância de peixes não residentes da zona estuarina, atraem o interesse da frota pesqueira, que atua sobre os estoques de forma intensa, muitas vezes levando a sobreexplotação. No estuário da Lagoa dos Patos, a Miragaia (Pogonias cromis), é um peixe estuarino dependente que por muitos anos foi um importante recurso pesqueiro, e hoje encontra-se sobreexplotado e ameaçado de extinção. As capturas que atingiram 1400 t em 1976, decaíram posteriormente e foram inexistentes nos anos de 2004, 2005, 2008, 2009 e 2010. Mas recentemente, se observa o aumento dos desembarques na região. A partir disso, a presente dissertação tem por objetivo descrever a pesca artesanal da Miragaia no estuário da Lagoa dos Patos e analisar o efeito da sobreexplotação no ciclo reprodutivo da população remanescente na região. No primeiro capítulo intitulado "A pesca artesanal da Miragaia (Pogonias cromis, Scieanidae) no estuário da Lagoa dos Patos", é discutida a hipótese de que os maiores valores de esforço e CPUE são encontrados no mesmo período de maior abundância da espécie no estuário, e verifica-se a influência do esforço de pesca nas variações da CPUE. De forma complementar, se confirma a distinta composição dos desembarques entre o período de desova e o resto do ano, a predominância de adultos no período de desova evidencia o aumento da abundância. No segundo capítulo intitulado "O efeito da sobreexplotação no ciclo reprodutivo da Miragaia (Pogonias cromis, Scieanidae)" é discutido a redução da idade e tamanho de primeira maturação sexual e consequentemente fecundidade dos exemplares, como consequência da sobrepesca sofrida pela espécie em anos anteriores. Os resultados encontrados mostram a situação preocupante da população de Miragaias no estuário da Lagoa dos Patos, onde a manutenção da intensidade pesqueira pode levar ao colapso da atividade e posterior extinção local da espécie. / The increase in the abundance of non-resident fish estuarine zone attract the interest of the fishing fleet, which operates on the intensely stocks, often leading to overexploitation. In the estuary of Patos Lagoon, the Black drum (Pogonias cromis) is an estuarine-dependent fish who for many years was an important fishing resource, and today is overexploited and threatened with extinction. Catches reached 1400 t in 1976, declined later and were negligible in the years 2004, 2005, 2008, 2009 and 2010. But recently observed increased landings in the region. Thus, this thesis aims to describe artisanal fishing of Black drum in the estuary of Patos Lagoon and analyze the effect of v overexploitation in the reproductive cycle of the remaining population in the region. In the first chapter entitled "The artisanal fishery Black drum (Pogonias cromis, Scieanidae) in the estuary of Patos Lagoon," discusses the hypothesis that higher values of effort and CPUE are found in the same period of greatest abundance of the species in the estuary, and there is the influence of fishing effort in changes in CPUE in a complementary way confirms the different composition of landings spawning periods for the rest of the year, the prevalence of adults in spawning highlights the increasing abundance. In the second chapter entitled "The effect of overexploitation in the reproductive cycle of Black drum (Pogonias cromis, Scieanidae)" is discussed reducing the age and size at first sexual maturity and consequently fertility of copies as a result of overfishing suffered by the species in previous years. The results show the worrying situation of the population of Black drum in the estuary of Patos Lagoon, where the maintenance of fishing intensity can lead to the collapse of activity and subsequent local extinction of the species.