Předkládaná práce by měla čtenáře blíže seznámit s chováním ryb, které tito živočichové vykazují vůči vlečným sítím během vzorkování pelagiálu vodních těles. Zaměřuje se na oblast v ústí tralu, kde je spektrum reakcí nejširší. Některé specifické rysy chování jsou uvedeny na příkladech z mezinárodních výzkumů v teoretické části. Jsou zde rovněž přiblíženy základní techniky, používané při studiu chování ryb ve vztahu k vlečným sítím. Praktickou částí je dvouletý výzkum (2009 a 2011) chování ryb na českých údolních nádržích Želivka a Římov ve vztahu k tralovým sítím. Chování ryb v ústí pelagického tralu bylo monitorováno prostřednictvím vertikálního sonaru SIMRAD EK 60 o frekvenci 38 kHz. Předmětem výzkumu bylo studium reakcí jednotlivých ryb se zaměřením na vertikální složku jejich pohybu. Zjišťovali jsme rozdíly mezi denní a noční aktivitou ryb, rychlost a sklon ve vodním sloupci, přímočarost trajektorie pohybu, souvislost mezi velikostí ryb a jejich rychlostí, a v neposlední řadě také vliv abiotických faktorů, které únikové chování podstatně ovlivňují. Znalost tohoto typu chování pomůže vypovědět o selektivitě zařízení, kterou je vhodné znát pro efektivní průzkum zdejších nádrží. Stejně tak užitečné jsou nové informace o vlastním chování ryb, které jsou přínosem nejen pro ekologii.

Submitted by Ricardo Cedraz Duque Moliterno (ricardo.moliterno@uefs.br) on 2016-03-01T00:26:45Z No. of bitstreams: 1 Disserta??o Luiz Alberto.pdf: 2080024 bytes, checksum: e6fbb727385961e9b7622db8acdbd075 (MD5) / Made available in DSpace on 2016-03-01T00:26:45Z (GMT). No. of bitstreams: 1 Disserta??o Luiz Alberto.pdf: 2080024 bytes, checksum: e6fbb727385961e9b7622db8acdbd075 (MD5) Previous issue date: 2013-02-04 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / A year-long otter trawl survey in the Todos os Santos bay (TSB) was conducted between November 2011 and September 2012 with the aim of describing the composition and structure of fish communities of the bay and check community fluctuations in both periods of the hydrological cycle (dry and wet). Fifty-three morphospecies were catch, comprising 10 orders and 29 families. The most representative families in terms of species richness were, respectively, Carangidae, Gerreidae, Syngnathidae, Engraulidae, Gobiidae and Paralichthyidae. Despite the significant number of species caught, the fish community of the Todos os Santos bay, on the beaches sampled with trawl, is dominated by five species: Atherinella brasiliensis, Sphoeroides greeleyi, Eucinostomus argenteus, Sphoeroides testudineus and Lile piquitinga, which represent 99.5% of the relative importance of the catch. Influences of environmental parameters of rainfall, temperature and salinity on the composition and structure of fish fauna of TSB were absent or very subtle. The use of different fishing gear (simple net and with bag) did not influence the values of CPUE for different beaches sampled. We can conclude that the shallow areas of the Todos os Santos bay have quite important for maintaining their fish stocks, since species (including commercial interest) to use, partially or completely, the TSB as nursery or creation area. / Um programa de amostragens bimstrais de arrasto de praia em seis esta??es de coleta na Ba?a de Todos os Santos (BTS) foi realizado entre novembro de 2011 e setembro de 2012 com o objetivo de descrever a composi??o e estrutura da comunidade de peixes da ba?a e verificar flutua??es da comunidade nos dois per?odos do ciclo hidrol?gico (seco e chuvoso). Cinquenta e tr?s morfoesp?cies de peixes foram levantadas, compreendendo 10 ordens e 29 fam?lias. As fam?lias mais representativas em termos de riqueza de esp?cie foram, respectivamente, Carangidae, Gerreidae, Syngnathidae, Engraulidae, Gobiidae e Paralichthyidae. Apesar do n?mero relevante de esp?cies capturadas, a comunidade ?ctica da Ba?a de Todos os Santos, nas praias amostradas com arrasto manual, ? dominada, basicamente por cinco esp?cies: Atherinella brasiliensis, Sphoeroides greeleyi, Eucinostomus argenteus, Sphoeroides testudineus e Lile piquitinga, as quais correspondem a 99.5% da import?ncia relativa das capturas. Influ?ncias dos par?metros ambientais de pluviosidade, temperatura e salinidade sobre a composi??o e estrutura da ictiofauna da BTS foram ausentes ou muito sutis. A utiliza??o de diferentes petrechos de pesca (rede simples e com saco) n?o influenciou nos valores de CPUE para as diferentes praias amostradas. O elevado n?mero de esp?cie tamb?m sugere que muitos peixes utilizam as zonas rasas da BTS como ?reas de cria??o, usufruindo da prote??o e alimento, portanto, pode-se concluir que as ?reas rasas da Ba?a de Todos os Santos possuem assaz import?ncia para manuten??o dos seus estoques pesqueiros, j? que esp?cies (inclusive de interesse comercial) a utilizam, parcial ou totalmente, como ?reas de ber??rio e/ou cria??o.

Rising fuel prices have been inflating the operating costs of the fishing industry. Trawl doors are used to hold the fishing net open during trawling operations, and they have a great influence on the fuel consumption of vessels. Improvements in the design of trawl doors could therefore contribute significantly to increased fuel efficiency. An efficient optimization algorithm using two- and three-dimensional (2D and 3D) computational fluid dynamics (CFD) models is presented. Accurate CFD models, especially 3D, are computationally expensive. The direct use of traditional optimization algorithms, which often require a large number of evaluations, can therefore be prohibitive. The proposed method is iterative and uses low-order local response surface approximation models as surrogates for the expensive CFD model to reduce the number of iterations. The algorithm is applied to the design of two types of geometries: a typical modern trawl door, and a novel airfoil-shaped trawl door. The results from the 2D design optimization show that the hydrodynamic efficiency of the typical modern trawl door could be increased by 32%, and the novel airfoil-shaped trawl door by 13%. When the 2D optimum designs for the two geometries are compared, the novel airfoil-shaped trawl door results to be 320% more efficient than the optimized design of the typical modern trawl door. The 2D optimum designs were used as the initial designs for the 3D design optimization. The results from the 3D optimization show that the hydrodynamic efficiency could be increased by 6% for both the typical modern and novel airfoil-shaped trawl doors. Results from a 3D CFD analysis show that 3D flow effects are significant, where the values for drag are significantly underestimated in 2D CFD models.

In conjunction with Cambrex, a biomedical company that utilizes horseshoe crabs for the production of Limulus Amoebocyte Lysate (LAL), a study was conducted to investigate movement patterns and population distributions of horseshoe crabs to increase understanding of mid-Atlantic horseshoe crab populations. In addition, areas of the shoreline of Tom's Cove, Assateague Island, Virginia were investigated as possible locations for annual spawning surveys. Twelve thousand five hundred horseshoe crabs were tagged and released in Chincoteague, Virginia and Ocean City, Maryland as part of a movement study; 431 (3.45%) were reported as resights. The mean distance between site of release and site of recapture for all resighted crabs was 68.3 km; maximum distance moved was 493.7 km. During 1999-2004, demographic data were collected from horseshoe crabs harvested in Chincoteague, VA and Ocean City, MD. The proportion of females (p < 0.0001) and juveniles (p < 0.0001) sampled varied from year-to-year, but no trends were observed. This study also showed that a greater proportion of females were observed in the juvenile cohort sampled compared to the adults sampled (p < 0.0001). The spawning survey revealed that spawning activity in Tom's Cove varied between years. On May 30th, 2003, 1,192 horseshoe crabs were observed spawning on the northern shoreline of Tom's Cove. The maximum number of horseshoe crabs observed spawning in the same area in 2004 was 94. This study provides no evidence for isolated subpopulations in Chincoteague, VA or Ocean City, MD. It also shows that horseshoe crab sex and age ratios fluctuate annually, therefore requiring a long time series of data to detect trends. / Master of Science

The bycatch of cetaceans in fishing gear is considered to be one of the biggest conservation threats to these species. Gear modifications have the potential to reduce these bycatches in global fisheries but there is little available information on how such modifications may change the fishing performance of gear, or indeed the behavior of cetaceans interacting with fishing gear. Generalized linear models (GLMs) were used to identify factors related to cetacean bycatches in UK bottom set gillnets. Rigged net height had a significant positive relationship with harbour porpoise (Phocoena phocoena) bycatch in ICES Area VII suggesting that lowering the profile of gillnets may have the potential to reduce bycatch rates. Modifications to gillnets, such as changing the amount of floatation or increasing the density of the meshes, were found to have significant effects on the active fishing heights of these nets. However, results from a bycatch mitigation trial in Argentina showed that the reduced fishing profile of one experimental net did not result in a concurrent reduction in the bycatch rate of Franciscana dolphins (Pontoporia blainvillei). While there was no significant difference in the rate, length or intensity of harbour porpoise encounters in the presence or absence of gillnets, the proportion of fast echolocation click trains were significantly higher when a net was present, indicating that porpoises either increased acoustic inspection of the net or foraging in the vicinity of the net. An analysis of underwater video footage collected inside trawl nets in an Australia fishery showed that bottlenose dolphins (Tursiops sp.) were present inside nets more frequently than they were caught and were actively foraging inside these nets. The orientation of dolphins inside these nets indicates that the current design of excluder devices used in this fishery could be improved to further reduce bycatch rates.

Submitted by Sandra Pereira (srpereira@ufrrj.br) on 2016-09-27T12:12:25Z No. of bitstreams: 1 2011 - Elisabete Coentr?o Marques.pdf: 4697334 bytes, checksum: cf49a0c9505e071c1faaa85f0240e1be (MD5) / Made available in DSpace on 2016-09-27T12:12:26Z (GMT). No. of bitstreams: 1 2011 - Elisabete Coentr?o Marques.pdf: 4697334 bytes, checksum: cf49a0c9505e071c1faaa85f0240e1be (MD5) Previous issue date: 2011-01-19 / The primary production represented by agriculture, livestock and fishing is the basis for establishment of attitudes towards the quality in this area. A raw material obtained with excellence standards is the first step to providing a safe product for consumer. The implementation of quality management system is a factor of growth and business success. A shrimp fishery trawl is a shipping company for capture and storage shrimps, thus necessitating the systems implementation ensure shrimp?s quality and safety, because it?s perishable, high commercial value and export. The objective in this work was to implement a management quality organized, represented by Manual of good handling practices to ensure safety of hygienical-sanitary for shrimp. Used a case study holistic and descriptive in a shrimp fishery trawl. The evidence collection is given through intensive direct observation and documentation. Used as research tools a check-list of Good Manufacturing Practices in establishments products/food suppliers from Sanitary Surveillance National Agency. After the first evaluation, elaborated the Manual of Good Practices on Handling of Fish and guided improvement actions, defining the basic situations that involve the capture and transport with measures to ensure the safe and sanitary quality and the instructions theoretical and practical training to develop operational techniques. Good results was achieved with the Manual as speed in providing service with a reduction in average time of work execution on board around 37,5%, higher prodution volume and profit improvement by reducing the loss by errors in manipulation, and these losses have increased from 0,5% for 0,15% considered a virtually total flow of production. With Manual of Good Practice for Handling Fish observed benefits to shrimp fishery trawl, shaping the quality and indicating ways to control production. / A produ??o prim?ria representada pela agricultura, pecu?ria e pesca ? a base para o estabelecimento de atitudes em prol da qualidade na ?rea dos alimentos. Uma mat?ria-prima obtida com padr?es de qualidade de excel?ncia ? o primeiro passo para disponibiliza??o de um produto in?cuo para o consumidor. A aplica??o de sistema de gest?o da qualidade ? um fator de crescimento e sucesso empresarial. Camaroneiro ? uma empresa mar?tima destinada ? captura e armazenagem de camar?es, necessitando, portanto da implementa??o de sistemas que garantam a qualidade higi?nico-sanit?rio e a seguran?a dos camar?es, por ser produto perec?vel, de alto valor comercial e de exporta??o. O objetivo dessa pesquisa, baseando-se no Ciclo de Deming, como pressuposto de diretriz para documenta??o de sistema de gest?o da qualidade, foi elaborar o Manual de Boas Pr?ticas de Manipula??o para barco camaroneiro com orienta??o de a??es t?cnicas de processo como forma de valorizar a mercadoria frente ao mercado competitivo. A metodologia utilizada foi o estudo de caso hol?stico e descritivo em um barco camaroneiro. A coleta de evid?ncias se deu por meio da observa??o direta intensiva e da documenta??o. Usou-se como instrumental de pesquisa o check-list de Boas Pr?ticas de Fabrica??o em estabelecimentos produtos/comercializadores de alimentos da Ag?ncia Nacional de Vigil?ncia Sanit?ria. Ap?s a primeira avalia??o, elaborou-se o Manual de Boas Pr?ticas de Manipula??o do Pescado e orientou-se a??es de melhoria, definindo as situa??es b?sicas que envolvem a captura e transporte com medidas que garantam as condi??es de seguran?a higi?nico-sanit?rias e as instru??es de ensino te?rico e pr?tico para desenvolver as t?cnicas operacionais. Obteve-se bons resultados com o Manual com agilidade na presta??o do servi?o com diminui??o do tempo m?dio de execu??o do trabalho a bordo em torno de 37,5 %, maior volume de produ??o e melhoria dos lucros pela diminui??o das perdas do produto por manipula??o incorreta, sendo que estas perdas passaram de 0,5% para 0,15% considerado um escoamento praticamente total da produ??o. Com a introdu??o do Manual de Boas Pr?ticas de Manipula??o do Pescado no local observou-se benef?cios para a embarca??o, modelando a qualidade e indicando formas de controle da produ??o.

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.

No description available.

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

The subject matter of this Bachelor´s thesis is the Eastern Baltic Sea cod. A literature review has been done regarding how environmental factors such as salinity, oxygen supply and temperature but also the size of the cod populations affects the migration patterns and the habitat choice of the cod. The result of the review shows that, when the eastern Baltic cod population is small, its area of distribution is restricted to the southern parts of the Baltic Sea. Moreover, high salinity leads to a larger area of distribution, while low oxygen content in the Deep Basins leads to vertical migrations, as well as further migrations south and north, to areas with better hydrological conditions. Finally the the cod tend to prefer habitats with warmer water, if the oxygen and salinity conditions are suitable, at least during the spawning period. This thesis also include estimation on how well the annual scientific trawl surveys performed by coastal Baltic countries, reflects the actual cod population size. This estimation is partly based on a critical review of available information about the trawl survey design in relation to cod migration patterns, distribution and habitat choice. Furthermore, a test has been done of how well the annual stock size estimates for the latest year, presented in the International Council for the Exploration of the Sea (ICES) Annual Reports of the Baltic Fisheries Assessment Working Group (WGBFAS), between the years 1996-2009 reflected the best available stock size estimates from 2010. The results indicate that the scientific trawl surveys might not work satisfactory. This indicates that further research must be done in the field, therefore possible alternatives such as comparisons of positioning data of commercial and scientific trawls and interviews with fishermen are suggested. / Denna uppsats handlar om torsken i det östra Östersjöbeståndet. En litteratursammanfattning har gjorts gällande hur miljömässiga faktorer såsom salthalt, syretillgång, temperatur samt storleken på bestånden påverkar migrationsmönster och habitatval hos torsken. Resultaten visar bland annat att när torskbestånden är små blir torskens utbredningsområden begränsade till de södra delarna av Östersjön. Höga salthalter leder till större utbredningsområden medan låga syrehalter i djupbassängerna leder till vertikala migrationer såväl som längre migrationer söder och norr om bassängerna, till områden med bättre syretillgång. Torsken verkar dessutom föredra habitat med varmare vatten om syre- och salthaltsförhållandena är gynnsamma, åtminstone under lekperioden. Vidare inkluderar denna uppsats en bedömning av hur väl de årliga vetenskapliga trålningsundersökningarna som utförs av länder med kust mot Östersjön, återspeglar den faktiska storleken på torskbestånden. Denna bedömning baseras på en kritisk granskning av den information som finns tillgänglig gällande de vetenskapliga trålningsundersökningarna, i förhållande till torskens migrationsmönster, distribution och habitatval. Dessutom har ett test gjorts av hur väl de årliga beståndsuppskattningarna för 1996-2009 presenterade i International Council for the Exploration of the Sea (ICES) Annual Report of the Baltic Sea Fisheries Assessment Working Group (WGBFAS), reflekterar de bästa tillgängliga beståndsuppskattningarna från 2010. Resultaten indikerar att de vetenskapliga provtrålningsundersökningarna inte fungerar tillfredsställande, vilket visar på att vidare studier måste göras inom området. Möjliga alternativ, såsom jämförelser av positioneringsdata för kommersiell- samt vetenskaplig trålning, samt intervjuer med yrkesfiskare presenteras.