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Understanding the sense of discourse relations that appear between segments of text is essential to truly comprehend any natural language text. Several automated approaches have been suggested, but all rely on external resources, linguistic feature engineering, and their processing pipelines are built from substantially different models. Instead of designing a system specifically for a given language and task, we pursue a language-independent approach for sense classification of shallow discourse relations. In this dissertation we first present our focused recurrent neural networks (focused RNNs) layer, the first multi-dimensional RNN-attention mechanism for constructing sentence/argument embeddings. It consists of a filtering RNN with a filtering/gating mechanism that enables downstream RNNs to focus on different aspects of each argument of a discourse relation and project it into several embedding subspaces. On top of the proposed mechanism we build our FR system, a novel method for sense classification of shallow discourse relations. In contrast to existing systems, the FR system consists of a single end-to-end trainable model for handling all types and specific situations of discourse relations, requires no feature engineering or external resources, can be used almost out-of-the-box on any language or set of sense labels, and can be applied at the word and character level representation. We evaluate the proposed FR system using the official datasets and methodology of CoNLL 2016 Shared Task. It does not fall a lot behind state-of-the-art performance on English, but it outperforms other systems without a focused RNNs layer by 8% on the Chinese dataset. Afterwards we perform a detailed analysis on both languages. Razumevanje smisla diskurznih relacij, ki nastopajo med segmenti besedila, je ključnega pomena za razumevanje kateregakoli besedila v naravnem jeziku. Številni avtomatizirani pristopi so že bili predlagani, vendar so vsi odvisni od zunanjih virov, ročno-idelanih značilk in njihovi cevovodi za procesiranje so izdelani iz bistveno različnih modelov. Namesto izdelave sistema specializiranega za dani jezik in nalogo, mi stremimo k jezikovno-neodvisnemu pristopu za klasifikacijo smisla v plitkih diskurznih relacijah. V pričujoči disertaciji najprej predstavimo naše osredotočene rekurentne nevronske mreže (focused RNNs), ki predstavljajo prvi več-dimenzionalni RNN-pozornostni mehanizem za izdelavo vložitev stavkov/argumentov. Sestavljen je iz filtrirnega RNN z mehanizmom za filtriranje/usmerjanje, ki omogoča sledečim RNN-jem, da se osredotočijo na različne vidike vsakega argumenta diskuzne relacije in ga projecirajo v več vložitvenih podprostorov. Omenjeni mehanizem uporabimo v našem sistemu FR system, ki predstavlja novo metodo za klasifikacijo smisla v plitkih diskurznih relacijah. V nasprotju z obstoječimi sistemi je FR system sestavljen iz enega modela, ki ga je mogoče celostno učiti od začetka-do-kraja, obravnava vse vrste in specifične situacije v diskurznih relacijah, ne potrebuje ročno-izdelanih značilk ali zunanjih virov, se lahko skorajda brez sprememb uporabi na kateremkoli jeziku ali oznakah smisla, in se lahko uporablja tako na ravni besed kot na ravni znakov. Predlagani FR system smo ovrednotili na uradnih podatkovnih zbirkah in po metodologiji izziva CoNLL 2016 Shared Task. Ne zaostaja veliko za najuspešnejšimi sistemi na angleškem jeziku, vendar presega ostale sisteme brez focused RNNs plasti za 8% na kitajski podatkovni zbirki. Nato smo izvedli natančnejšo analizo na obeh jezikih.

The EU Landing Obligation (LO) is designed to reduce bycatch (i.e. unwanted catch) through more selective fishing practices, such as avoidance behaviours which consist in allocating fishing effort to other species, fishing grounds or seasons. Incentives for fishers to change their behaviours depend on their economic performances as well as their ability to avoid bycatch. Changes in economic performances under the LO are evaluated based on cost and revenue equations. The nested grid method is then used to explore the spatial and temporal distribution of landings and discards, and to suggest alternative effort allocation to avoid bycatch. This article is focussed specifically on the French otter trawl fishery in the eastern English Channel and southern North Sea. Results suggest that under the LO the choke species problem will curtail fishing activities earlier in the year, leading to significant economic losses. In the absence of significant quota top-ups (at least 75%), a change in fishing practices consisting in reducing overall bycatch by 30% is insufficient to reduce losses. With a particular attention to choke species, more economically efficient avoidance strategies can be found thanks to the nested grid method.

Special issue on Discards regulation vs Mediterranean fisheries sustainability.-- 10 pages, 5 figures, 5 tables, supplementary material http://scimar.icm.csic.es/scimar/supplm/sm04784esm.pdf, [EN] There is currently very little information on the survival to discarding of unwanted and non-regulated catches of invertebrates, after the stresses due to capture. A great number of the non-regulated invertebrate species are the basis of Essential Fish Habitats for important fisheries resources such as hake, red mullet or cuttlefish. Thus, data on their survival to discarding may help to interpret the role of these species within the benthic ecosystems. Furthermore, descriptor 6 of Marine Strategy Framework Directive (MSFD, EU Directive 2008/56/E) foresees maintaining sea floor integrity at a level that ensures that the structure and functions of the ecosystems are safeguarded and article 7(d) of the Common Fishery Policy (CFP, EU Reg. 1380/2013) foresees the implementation of management measures for fishing with low impact on the marine ecosystem and fishery resources. Survival measurements by direct recovering tagged discarded species are not effective in bottom trawl fisheries for which alternative studies, such as semi-quantitative measures obtained on board prior to discarding, can be considered as appropriate for mortality estimation. The present work assessed the survival of unwanted species using a Semi-Quantitative Assessment (SQA) on deck of trawlers and at the laboratory for a period of 96 hours in two Mediterranean areas (Catalan Coasts and Ligurian and Northern Tyrrhenian Sea). The results showed that a high number of discarded invertebrates had a high percentage of survival (>70%) in both assessments. The purpose of these results is to provide information that can help to achieve higher survival levels of the discarded specimens. At the same time, it is expected that this improvement can enhance the productivity of the fishing grounds by increasing the health of the benthic ecosystems, [ES] Actualmente, hay muy poca información sobre la supervivencia del descarte de los invertebrados no-deseados y no-regulados después del stress de la captura. Un gran número de especies de estos invertebrados son básicas para los hábitats esenciales de importantes recursos pesqueros como la merluza, el salmonete o la sepia. Por lo tanto, información sobre su supervivencia al ser descartados pueden ayudar a interpretar el papel de estas especies dentro de los ecosistemas bentónicos. Además, el punto 6 de la Directiva Marco de Estrategia Marina (MSFD, EU Directive 2008/56/E) prevé mantener la inte-gridad del fondo marino a un nivel que garantice la protección de la estructura y de las funciones de los ecosistemas, y el artículo 7 (d) de la Política Pesquera Común (PPC EU Reg. 1380/2013) prevé la implementación de medidas de gestión para la pesca, que tengan bajo impacto tanto en el ecosistema marino como en los recursos pesqueros. En el caso de las pescas de arrastre de fondo, no es efectiva la estimación de la supervivencia a partir del método directo de captura-recapture de las especies del descarte marcadas, por lo que los estudios alternativos, como las medidas semicuantitativas obtenidas a bordo antes del descarte, pueden considerarse una estimación de la mortalidad apropiada. El presente trabajo evaluó la supervivencia del descarte de especies no-deseadas utilizando una Evaluación Semicuantitativa (SQA) mediante dos estudios: uno sobre la cubierta de los arrastreros y el otro en laboratorio durante un período de 96 horas, en dos áreas del Mediterráneo, las costas Catalanas y en los mares de Liguria y del Tirreno Norte. Los resultados mostraron en ambos estudios, que un alto número de invertebrados descartados tenía un alto porcentaje de supervivencia (>70%). El propósito de estos resultados es proporcionar información que puede ayudar a alcanzar niveles de supervivencia más altos de los individuos descartados. Al mismo tiempo, se espera que con esta mejora se consiga potenciar la productividad de los caladeros al aumentar la salud de los ecosistemas bentónicos, This study received funding from the European Commission’s Horizon 2020 Research and Innovation Programme under Grant Agreement No. 634495 for the project “Science, Technology, and Society Initiative to Minimize Unwanted Catches in European Fisheries” (MINOUW)

Special issue on Discards regulation vs Mediterranean fisheries sustainability.-- 10 pages, 6 figures, 7 tables, [EN] With the full implementation of the landing obligation on 1 January 2019, In European waters it will become mandatory for the trawling fleet to land at port all catches of certain species because, according to Article 15 of the new European Common Fisheries Policy, the species subject to the minimum conservation reference size (MCRS) cannot be discarded. Additionally, since 2005, trawlers over 15 m in length are required to carry an onboard vessel monitoring system (VMS), which generates information on fleet dynamics. The objective of this work was to provide a tool for avoiding unwanted catches by integrating the catch study of trawlers operating in the port of Blanes together with VMS data. To achieve this objective, the catches of 40 hauls were monitored, sampled and analysed together with VMS data for the years 2012-2014 integrated in a geographical information system. The results show that specimens below the MCRS were often captured in crinoid aggregation habitats, bottoms with maërl and muddy bottoms that were identified as nursery habitats of commercial species, e.g. Merluccius merluccius, Pagellus spp. and Mullus spp. VMS data showed considerable fishing pressure on areas with maërl and muddy habitats during the recruitment periods of these and other commercially relevant species. Implementing spatial or seasonal closures in habitats where species regulated by the MCRS are subject to catches could be a useful tool for preventing unwanted catches, [ES] Con la plena aplicación de la Obligación de desembarque a partir del 1 de enero de 2019, pasará a ser obligatorio para la flota de arrastre desembarcar en puerto todas las capturas de ciertas especies, que según el Artículo 15 de la nueva política pesquera común no pueden ser descartadas, ya que están sujetas a MCRS. Por otro lado, desde 2005, se requiere a los arrastreros de más de 15 m de longitud, llevar a bordo un VMS, que proporciona información acerca de la dinámica de la flota. El objetivo de este trabajo fue proporcionar una herramienta para evitar capturas no deseadas integrando el estudio de la captura de arrastreros que operan en el puerto de Blanes junto con datos VMS de la flota de arrastre. Para lograr dicho objetivo, las capturas de 40 lances fueron monitoreadas, muestreadas y analizadas junto con los datos VMS de los años 2012-2014 integrados en un Sistema de Información Geográfica. Los resultados muestran que se capturaron de forma notable especímenes por debajo de la MCRS en hábitats de agregación de crinoideos, fondos con presencia de maërl y fondos fangosos que fueron identificaron como hábitats de cría para especies como Merluccius merluccius, Pagellus spp. y Mullus spp. Los datos VMS mostraron una notable presión pesquera en hábitats fangosos y fondos con presencia de maërl durante los períodos de reclutamiento de estas y otras especies comerciales relevantes. El uso de cierres espaciales o temporales en hábitats sujetos a descarte de especies reguladas por MCRS podría ser una herramienta útil para evitar capturas no deseadas, This work was funded by the research project MINOUW (H2020-SFS-2014-2) from the European Commission (contract nº 634495). We also acknowledge the help of the vessels’ crew during sampling and the data provided by MAGRAMA, which were indispensable for meeting the objectives of this work

With the full implementation of the landing obligation on 1 January 2019, In European waters it will become mandatory for the trawling fleet to land at port all catches of certain species because, according to Article 15 of the new European Common Fisheries Policy, the species subject to the minimum conservation reference size (MCRS) cannot be discarded. Additionally, since 2005, trawlers over 15 m in length are required to carry an onboard vessel monitoring system (VMS), which generates information on fleet dynamics. The objective of this work was to provide a tool for avoiding unwanted catches by integrating the catch study of trawlers operating in the port of Blanes together with VMS data. To achieve this objective, the catches of 40 hauls were monitored, sampled and analysed together with VMS data for the years 2012-2014 integrated in a geographical information system. The results show that specimens below the MCRS were often captured in crinoid aggregation habitats, bottoms with maërl and muddy bottoms that were identified as nursery habitats of commercial species, e.g. Merluccius merluccius, Pagellus spp. and Mullus spp. VMS data showed considerable fishing pressure on areas with maërl and muddy habitats during the recruitment periods of these and other commercially relevant species. Implementing spatial or seasonal closures in habitats where species regulated by the MCRS are subject to catches could be a useful tool for preventing unwanted catches., Con la plena aplicación de la Obligación de desembarque a partir del 1 de enero de 2019, pasará a ser obligatorio para la flota de arrastre desembarcar en puerto todas las capturas de ciertas especies, que según el Artículo 15 de la nueva política pesquera común no pueden ser descartadas, ya que están sujetas a MCRS. Por otro lado, desde 2005, se requiere a los arrastreros de más de 15 m de longitud, llevar a bordo un VMS, que proporciona información acerca de la dinámica de la flota. El objetivo de este trabajo fue proporcionar una herramienta para evitar capturas no deseadas integrando el estudio de la captura de arrastreros que operan en el puerto de Blanes junto con datos VMS de la flota de arrastre. Para lograr dicho objetivo, las capturas de 40 lances fueron monitoreadas, muestreadas y analizadas junto con los datos VMS de los años 2012-2014 integrados en un Sistema de Información Geográfica. Los resultados muestran que se capturaron de forma notable especímenes por debajo de la MCRS en hábitats de agregación de crinoideos, fondos con presencia de maërl y fondos fangosos que fueron identificaron como hábitats de cría para especies como Merluccius merluccius, Pagellus spp. y Mullus spp. Los datos VMS mostraron una notable presión pesquera en hábitats fangosos y fondos con presencia de maërl durante los períodos de reclutamiento de estas y otras especies comerciales relevantes. El uso de cierres espaciales o temporales en hábitats sujetos a descarte de especies reguladas por MCRS podría ser una herramienta útil para evitar capturas no deseadas.

North Kalimantan Province, notably Tarakan City marine waters, is one of the important fishing ground in boundary area among Sulu Sulawesi Marine Ecoregion. It produces approximately 100 mt/annum of Bombay duck (Harpadon nehereus) with valued of US$ 750,000. The sustainability of this fishery is a crucially concern given the following: substantial economic contribution, significant dependence of small-scale fishers on this species for their livelihoods. The fishing intensities considerable and growing threats to their habitats. To evaluate the vulnerability of individual species to over exploitation, the spawning potential ratio (SPR) approach applied to describe the status of its existing fisheries. This approach provides the ability to determine fishing mortality as reference points to enhance its sustainability. The objective of this study is to understand this fish biomass resilience to harvesting. The calculated SPR based on the value of estimated length of first capture or Lc at 208 mm is equivalent to the SPR of 28%. With a base line of stocks are generally thought to risk recruitment declining when SPR

Aquatic animals fished by 37 operations of a small beam trawl net at the Hibiki-nada Sea off Yamaguchi Prefecture, Japan, were surveyed in all seasons from 2002 through 2009. A total of 317 species including 1 chordate, 204 fishes (FS) and 112 invertebrates (IV) were caught. Among them,126 FS and 75 IV were judged as rare (caught in less than 8 operations), 36 FS and 28 IV as occasional(8 to 14 operations), 21 FS and 8 IV as often(15 to 22 operations),16 FS and 1 IV as frequent(23 to 29 operations), and 5 FS and 0 IV as general (more than 29 operations). Sixty-eight FS and 28 IV were caught in all seasons,107 FS and 71IV were in spring,139 FS and 79 IV were in summer,148 FS and 81 IV were in autumn, and 125 FS and 43 IV were in winter. From distributional point of view, 70 FS and 42 IV were subtropical species, 91 FS and 62 IV were temperate region species, and 43 FS and 7 IV were large areal species.

Material suplementar disponível em: http://journal.frontiersin.org/article/10.3389/fmars. 2017.00277/full#supplementary-material Almost all of the world’s fisheries overlap spatially and temporally with foraging seabirds, with impacts that range from food supplementation (through scavenging behind vessels), to resource competition and incidental mortality. The nature and extent of interactions between seabirds and fisheries vary, as does the level and efficacy of management and mitigation. Seabird dietary studies provide information on prey diversity and often identify species that are also caught in fisheries, providing evidence of linkages which can be used to improve ecosystem based management of fisheries. However, species identification of fish can be difficult with conventional dietary techniques. The black-browed albatross (Thalassarche melanophris) has a circumpolar distribution and has suffered major population declines due primarily to incidental mortality in fisheries. We use DNA metabarcoding of black-browed albatross scats to investigate their fish prey during the breeding season at six sites across their range, over two seasons. We identify the spatial and temporal diversity of fish in their diets and overlaps with fisheries operating in adjacent waters. Across all sites, 51 fish species from 33 families were identified, with 23 species contributing >10% of the proportion of samples or sequences at any site. There was extensive geographic variation but little inter-annual variability in fish species consumed. Several fish species that are not easily accessible to albatross, but are commercially harvested or by-caught, were detected in the albatross diet during the breeding season. This was particularly evident at the Falkland Islands and Iles Kerguelen where higher fishery catch amounts (or discard amounts where known) corresponded to higher occurrence of these species in diet samples. This study indicates ongoing interactions with fisheries through consumption of fishery discards, increasing the risk of seabird mortality. Breeding success was higher at sites where fisheries discards were detected in the diet, highlighting the need to minimize discarding to reduce impacts on the ecosystem. DNA metabarcoding provides a valuable non-invasive tool for assessing the fish prey of seabirds across broad geographic ranges. This provides an avenue for fishery resource managers to assess compliance of fisheries with discard policies and the level of interaction with scavenging seabirds. info:eu-repo/semantics/publishedVersion

Source at https://doi.org/10.2960/J.v49.m715. Greenland halibut (Reinhardtius hippoglossoides) is a commercially important species in the northeast Atlantic trawl fishery. However, direct fishing for it is not allowed and it can only be harvested as bycatch. We investigated for the first time the size selection of Greenland halibut in a newly developed double steel grid system designed for the cod and haddock bottom trawl fishery. In this sorting system the first grid (lower grid) replaced the lifting panel present in the traditional Sort-V single grid system often applied in the fishery. Thus, it contributed to the fish sorting process and simultaneously guided fish to the second grid (upper grid). However, the results showed that nearly all Greenland halibut escapees left through the second grid. The release efficiency of the first grid was estimated to be low, and only 11% of the Greenland halibut entering the grid zone made contact with this grid in a way that provided a size-dependent release probability. In contrast, the estimations showed that all Greenland halibut, still in the gear after the first grid, made contact with the second grid. However, this contact was suboptimal for size selection of most individuals, as the estimated 50% retention length (based on the morphology of Greenland halibut) was below the expected value. Comparison of the release efficiency of the new double grid system relative to that of the grid systems used in the fishery today revealed that the new system did not improve the release of undersized Greenland halibut. Moreover, we found that the existing Sort-V single grid system released significantly more Greenland halibut than the new double grid system.

Time-series of fishing position, landings, satellite-derived sea-surface temperature and chlorophyll a concentrations were used to relate the spatial-temporal distribution of the Argentine hake Merluccius hubbsi with seasonal oceanographic processes in San Matías Gulf. Also, the seasonal effect of fishing on the hake population structure was analysed. During summer the fleet was concentrated over the area of the frontal system, obtaining the best catch-per-unit-effort (CPUE) of hake in relatively deep waters. In autumn, the dispersion of the fleet due to a reduction in CPUE coincided with the dissipation of the front, suggesting that the distribution and shoaling of the Argentine hake is associated with seasonal thermal structures. In spring, the thermal structure of the waters and the chlorophyll a blooms seem to modulate the timing of spawning of hake, which occurs mainly in October-November. In addition, the fleet captured a higher proportion of females in the gonadal recovery stage during warm months (November-April). While winter catches (May-October) consisted mainly of males, the intense summer fishing may result in a high impact on the female population. This information is relevant to design of spatial management tools intended to provide biological sustainability to the hake fishery. Fil: Ocampo Reinaldo, Matías. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Leibniz Centre for Tropical Marine Ecology; Alemania Fil: González, Raul Alberto Candido. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Williams, Gabriela Noemí. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Storero, Lorena Pia. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Romero, Maria Alejandra. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Narvarte, Maite Andrea. Universidad Nacional del Comahue. Instituto de Biología Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Gagliardini, Domingo Antonio. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; Argentina

The otter-trawl fishery led the capitalistic fisheries development in Japan and was characterized by an investment from outside the fisheries section and a typical capitalistic management by reason of this imported large-scale fishery. This fishery was developed in the East China Sea and the Yellow Sea apart from the coastal areas where conflicts with the coastal fisheries were caused frequently. This paper describes the development process of this fishery before the Second World War in both view points of the economic management and the covering of the entire sea area. The development process is divided into four periods. (1) Fisheries establishment－the First World War After some wooden boat trials, the steel otter-trawl fishery gained ground in 1907 and expanded rapidly by vigorous outside investment while including any speculators. The technology was transferred to domestically. The government exchanged the policy from encouragement to isolation of the fishing ground to the East China Sea and the Yellow Sea. Due to over-fishing and malmanagement during the recession, the trawl fishery fell into a slump. However, at the moment of rapid rising boat-prices during the War, almost all boats were sold out. (2) The First World War－the beginning of the Showa era When the trawl boats became few left, the government restricted the number of boats available for protection of fish-stock and the trawl fishery itself. As boat-prices went down a few years after the War, trawl boats were constructed again up to the limitation. Compared to before the War, the boat owners were selected on the marine industries relative persons list. The Kyoudo-gyogyo Company increased by collecting the boats, heightening productivity through an introduction of new technology, and settling the branch factory in Taiwan. While a large number of pair-boats trawl embarked to the East China Sea and the Yellow Sea, it resulted in a severe competition with the ottertrawl fishery and the captured fish had changed from valuable breams to material fish of the paste. (3) The Great Depression－the China-Japan War During the Great Depression, trawl fisheries managements fell dull, while the Kyoudo-gyogyo Com. rationalized through a settlement of its own base, and consolidated other trawlers resulting in the exclusive position of the otter-trawl fishery, and advanced to the pair-boats trawl fishery. Further, this company built for the first time a diesel boat installed with a freezer capable of working on the distant voyage. This company settled a branch factory in Hong Kong, however it didn't continue by reason of the anti-Japanese movement against the Manchurian Incident. After the depression, a rise of fish price together with inflation improved its management. (4) the China-Japan War－the Asia-Pacific War During the war time, a lack of fisheries material, a conscription of the boats and the crews, and also the war damage annihilated the trawl fishery ultimately. Kyoudou-gyogyo Com. and other trawlers had been reorganized toward the nationally controlled company, while the newly established companies in Taiwan and in Shanghai had accomplished their roll to supply the fishes until the end of the War., 汽船トロールはその発祥から第二次大戦までの40年弱の期間を，社会経済情勢や許可隻数と漁獲高の推移から４期に分けることができる。 (1) 明治41年から第一次大戦まで 明治41年に汽船トロールが英国から導入されて確立する。それ以前の木造船はもとより，同時に国内で建造された鋼船もその性能において大きく劣っていた。漁獲成績が良かったことから漁船数が急増し，国産技術として確立するのも早かった。参入してきたのは，漁業と無縁な投機家や造船所，汽船捕鯨の関係者などであった。造船所は日露戦後の沈滞を打破する業種として，汽船捕鯨は隻数が制限されて新たな投資先として同じ汽船漁業のトロールに注目したのである。投資規模，漁業技術ともに在来漁業とは隔絶しており，経営方法も会社組織による資本制経営がとられた。トロール漁業者は大きく九州勢と阪神勢に分かれ，互いに反目し，統一行動が出来なかった。トロール経営は漁労中心主義で経営を考えない粗略なものが多かった。初期の汽船トロールは規制がなく，沿岸域で操業したことから沿岸漁民・団体の猛反対を受け，政府も該漁業を大臣許可漁業とし，沿岸域を禁止漁区にするとともに遠洋漁業奨励法による奨励を廃止した。禁止漁区の設定で，漁場は朝鮮近海に移るが，新漁場が次々発見されて漁獲量が増大し，魚価も維持されたので明治42・43年には早くも黄金期を迎えた。トロール漁業の根拠地は，漁場に近く，漁港施設，漁獲物の鉄道出荷に便利な下関港を中心に，長崎港，博多港に収斂した。トロール漁業誘致のため，漁港施設・魚市場の整備が進められ，魚問屋の中からトロール漁獲物を扱う業者が現れた。トロール船の急増で漁場が狭くなり，禁止漁区の侵犯が頻発すると，禁止区域が拡大され，漁場は東シナ海・黄海へ移った。漁場が遠くなって経費が嵩む一方，魚価が低下するようになってトロール経営は一転して不振となった。ただ，漁船は惰性で増加を続け，大正２年には最大となる139隻に達した。苦境を脱する方法として，多くの経営体は合同して経営刷新を目指した。その代表が阪神勢を中心とした共同漁業(株)である。これら業者は第一次大戦が勃発して船価が急騰すると欧州などへ売却してトロール漁業から退散する。一方，生産力を高めてトロール漁業に留まった田村市郎率いる田村汽船漁業部は第一次大戦中の魚価の暴騰による利益を独り享受しつつ共同漁業を掌中に収める。台湾にも内地より数年遅れで内地のトロール船を用船する形で導入された。だが，島内の鮮魚需要は弱く，定着しないまま，第一次大戦によって漁船が売却されて中断している。機船底曳網とは違い，汽船トロールは現地の他漁業の反対により台湾・香港以外を根拠地とすることがなかった。 (2) 第一次大戦後から昭和初期まで 第一次大戦でほとんどのトロール船が売却されたのを機に，政府は隻数制限と一定の船舶能力を求めた。戦後，船価が下がってトロール船の建造が始まり，大正12年に70隻の制限隻数に達した。戦前と戦後ではトロール漁業は一変した。船主は少なくなり，とくに投機家や捕鯨関係者が姿を消し，共同漁業が最大手として支配力を高めた。その他に造船所や北洋漁業関係者の参入があった。北洋漁業関係者は，北洋漁業の再編成と絡んでトロール漁業と関係した。汽船トロールが制限隻数に達した頃から以西底曳網が台頭し，トロール漁業と同じ東シナ海・黄海に進出して漁獲競合が始まった。以西底曳は汽船トロールに比べて，生産性はやや劣るものの，初期投資，漁業経費ははるかに少なく，収益性に遜色がないことから，下関や長崎の魚問屋や徳島県漁業者によって急成長をうげた。以西底曳網の大量進出もあって，漁獲物はタイ類が急激に減少し，ねり製品原料の「潰し物」が中心となった。資源の維持と漁業調整のため，以西底曳網に対しては新規許可の停止と50トン未満にトン数規制をし，汽船トロールに対しては東シナ海・黄海で操業しない場合は70隻制限の対象外とされた。これを機に以西底曳網を集積した林兼商店などが汽船トロールに参入し，反対に共同漁業は以西底曳網を取り込むようになった。共同漁業はトロールの技術改良を先導し，無線電信の装備によって，魚価と販売状況を見ながらの生産・出荷対応をとるようになり，VD 式漁法の導入によって生産性を大幅に高めた。戦後は不況が続き，魚価が低迷する中で，他社からトロール経営を委託されるようになった。台湾においても大戦後，トロール漁業が再興したが，需要が停滞して中断し，昭和２年に共同漁業が蓬莱水産(株)を設立し，VD 式漁法を持ち込んで，３度目にしてようやく定着した。 (3) 昭和恐慌期から日中戦争まで 昭和恐慌により，生産量はやや減少したが，魚価が暴落して金額は急落した。以西底曳網は漁船の大型化が認められ，汽船トロールとの競合がますます激化して，トロール経営は厳しさを増した。共同漁業への経営委託，さらには共同漁業へのトロール船の売却が進み，トロール漁業では共同漁業が独占的な地位を築いた。共同漁業にとって，受託経営より直接経営の方が漁業経費の節減，付加価値の向上に有利と判断した。その共同漁業は，昭和２年に世界初のディーゼルトロール船を建造し，５年からは船内急速冷凍機をつけて，南シナ海，ベーリング海へ出漁するようになった。スチーム船に比べ，漁船は大型化し，長期航海が可能となった。漁船の建造費は高いが，漁業収入，漁業経費，漁業粗利益ともディーゼル船の方が高くなった。漁業経費のうちト料費はスチーム船と変わらなくなった。重油価格の低下と電動ウィンチの開発によってディーゼル化が可能になった。ベーリング海はミール工船事業が始まり，その付属船として使用されたが，事業は成功しなかった。この期間，ミール工船の事業者がトロール船の船主として顔を出す。また，共同漁業は昭和４年末から根拠地を下関から戸畑に移し，関連企業を集積して一大総合水産基地を構築する。漁業用資材，トロールや以西底曳網，流通・加工部門を統合して，経費の節減と付加価値の向上を図った。この共同漁業にあって田村汽船漁業部以来一貫してトロール経営の実務を担当したのは国司浩助であり，新技術の導入と科学的合理的な経営手腕によってトロール漁業の発展を導いた。台湾の蓬莱水産は，昭和６年に共同漁業と共同で香港を根拠地として南シナ海で操業する会社を設立する。香港での販売と同時に，郵船・商船を利用して内地，台湾などとの販売ネットワークを構築した。しかし，世界恐慌による不況と満州事変を契機とした排日運動により，香港以外での販売，トロール船の台湾への退避を余儀なくされた。 (4) 日中戦争からアジア・太平洋戦争まで 日中戦争の勃発によりトロール船及び乗組員の徴用が始まり，また漁業用物資の欠乏が顕著となって，トロール漁獲量は低下から急落へと向かい，戦争の深化とともに崩壊した。魚価は一時的に財政・軍事インフレのために暴騰し，第２の黄金期を現出したが，その後，終末へと向かう。共同漁業は関連水産企業を統合し，日産コンツェルンの傘下で日本水産(株)となった。元々，共同漁業の田村市郎，国司浩助らは日産コンツェルンの総帥・鮎川義介とは人的なつながりがあり，早くから提携している。共同漁業は南シナ海の他に，昭和10年代初めに豪州沖，中南米沖出漁を始めたが，いずれも戦争の足音が高くなると中止となった。南シナ海へは林兼商店も出漁している。台湾でのトロール漁業は，香港から退避したトロール船を加えて，南シナ海への出漁が一時，興隆したが，徴用によって規模が縮小し，終戦を迎える。他に昭和13年に占領地・上海に国策水産会社が設立された。日本水産や林兼商店などがトロール船や機船底曳網漁船を現物出資した。水産統制令によって昭和18，19年に日本水産，林兼商店，そして台湾のトロール会社はいずれも統制会社に再編された。ただし，その頃にはトロール船も機船底曳網漁船も壊滅状態であった。, 長崎大学水産学部研究報告, 94, pp.29-55; 2013

The use of the turtle excluder device (TED) has been mandatory in Brazil since 1994. In spite of the importance of sea turtle bycatch reduction, TED effectiveness to maintain target species capture had never been evaluated in shrimp fisheries off southern Brazil. For this purpose, a test was carried out in November 2013 with the TED installed with two different configurations, top or bottom opening under the supervision of a technician of the National Oceanic and Atmospheric Administration (NOAA). Absolute catch and fishery yields were simultaneously monitored in 10 fishing hauls of a double-rig trawler by an onboard observer in one net equipped with a TED and the other without a TED. Although a Bayesian hypothesis test demonstrated no significant differences through the simultaneous comparison of absolute capture considering the use and non-use of the TED, the credibility interval of posterior beta distributions intercepted almost its minimum limit which weakens the hypothesis of equality. In terms of orientation, the model mounted with the top opening showed no differences in absolute catches of the target species in respect to control.

10 pages, 6 figures, 2 tables, [EN] In this work we analysed the spatio-temporal variability of discards in the fishery of the deep-sea red shrimp Aristeus antennatus in the northwestern Mediterranean Sea. We sampled fishery discards in the fishing grounds of Palamós (the main harbour for this fishery on the Catalan margin), which are located in several areas of a submarine canyon. We found that the discard ratio in this fishery showed a marked seasonal variability, with a maximum in spring and a minimum in summer. Most of the discarded biomass (almost 96%) were of species with no commercial interest. Within these, the most represented group was elasmobranchs, making up to more than 50% of total discarded biomass. Our findings show that the landing obligation established by the EU will have a low impact in mitigating discards in this fishery, as the vast majority of discards are non-commercial species that are not specified in the regulation. Alternative management strategies, such as a temporary fishery closure in spring (when the discard ratio reaches its maximum), should be considered in order to preserve the vulnerable ecosystem hosted by the submarine canyon, [ES] En este estudio se analizó la variabilidad espacio-temporal de los descartes en la pesquería de la gamba roja de profundidad Aristeus antennatus en el mar Mediterráneo Noroccidental. Para ello se muestrearon las capturas obtenidas en los caladeros de Palamós (el mayor puerto para esta pesquería en Cataluña), que están localizados en diferentes áreas adyacentes a un cañón submarino. Nuestros resultados demuestran que la proporción de descartes en las capturas de esta pesquería presenta una marcada variabilidad estacional, con un máximo en primavera y un mínimo en verano. La mayoría de la biomasa de los descartes (casi el 96%) está constituida por especies sin ningún interés comercial. Entre éstas, el grupo más representado es el de los elasmobranquios, que constituye más del 50% de la biomasa total de los descartes. Nuestros resultados indican que la obligación de desembarcar las capturas establecida por la UE tendrá un impacto bajo en disminuir los descartes en esta pesquería, ya que la gran mayoría de los descartes está constituida por especies no comerciales que no están especificadas en la regulación. Medidas de gestión alternativas, como el establecimiento de una veda en primavera (cuando la proporción de descartes llega a su máximo) deberían considerarse para preservar el ecosistema vulnerable de este cañón submarino, Finally, the EC Programme Science in Society EC FP7 (grant agreements 266544-GAP2 and 287600-PERSEUS), the FPU grant of the Spanish Ministry of Education and the Marine Stewardship Council are acknowledged for their financial support

In input-controlled multi-specific fisheries, seasonal closure has little biological rationale as a management measure, because it is difficult to adjust such closure for many target species and, in most cases, they are adopted for economic purposes. We aimed to determine effects of closure in biologic and economic terms, using 10-year landing data from two representative trawling ports of the Western Mediterranean: Dénia and La Vila Joiosa. Analysis of Variance (ANOVA) was used to detect significant differences, before and after the closure, in standardized catch per unit effort (CPUE) at different seasons and sale prices at home/closed and neighbour/open ports. ANOVAs showed significantly higher CPUE after the closure for total landings and Mullus spp. of the Red mullet métier, Merluccius merluccius CPUE (in two years) and the total landings of the Norway lobster métier. On the contrary, significant lower values were observed after the closure for total CPUE (in early summer) and Aristeus antennatus of Red shrimp métier. Similar CPUE was observed at all levels when the closure took place in late summer. In economic terms, market prices of target species have decreased or shown no changes after the closure at home/closed and neighbouring/open ports. The only exception was the significant increase of the price for A. antennatus in Dénia during the closure in La Vila Joiosa. Depending on its timing, the closure would highlight some positive biological effects on some target species. However, closure leads to an unavoidable reduction in most of target species prices. An alternative management measure that is based on effort reduction in input-controlled multi-specific fisheries could ban one day per week when market prices of target species are lower. M. Samy-Kamal was supported by a grant of the Spanish Agency for International Development Cooperation (AECID).

Since June 2010 the Italian government prohibited the trawling activity within three nautical miles from the coast or within the 50 m isobath. This decision was expected to have a great impact on trawl fishing activities, but at the moment no real assessment of the effects on catches and possible ecological implications has been undertaken. In order to fill this gap, an assessment on the North Western Adriatic Sea coast has been performed. Landings per Unit of Effort (kilograms per boat per day) for each trawling fleet segment have been analysed, by comparing on a monthly basis the before (2007–2009) and after ban (2011–2013) period. The comparison was carried out considering total landings and the six main species targeted inside the three miles area (sand smelt, cuttlefish, red mullet, sole, turbot, and mantis shrimp). Within a general reduction of total landings, a differential effect based on the analysed metiers was detected, with small trawlers being more negatively affected than the large and rapido ones, which showed, for some species, positive impacts. From an ecological point of view, though, no positive overall effects were detected, probably due to the fact that the adopted measure is not sufficient to reduce the overexploitation. In any case, all this is affecting the structure of the small-scale fishery in the area, since small trawlers are changing metier, moving towards the artisanal fishery, with deep impacts on the very coastal area that the trawling ban was designated to protect, compromising all possible benefits.

The daily variation of fishing effort and ex-vessel price was analysed to determine which day of the week is suitable to ban the fishery, as an alternative management measure to the one month seasonal closure. Thus, 10-years landings data were used from two representative trawling ports of the western Mediterranean: Dénia and La Vila Joiosa. Analysis of variance (ANOVA) was used to detect significant differences in fishing effort (total and by métier) and daily ex-vessel price of the main target species. Also, the economic loss produced by banning one day (the proposed measure) was compared to economic loss produced by the seasonal closure (the actual measure). Daily variation in the fishing effort was observed in La Vila Joiosa mainly due to higher effort at the end of the week devoted on crustacean métiers, while effort was similar among days in Dénia. The lowest mean prices for most target species were on Tuesday and Wednesday, and were higher on Monday and Friday. Banning one day per week (Tuesday or Wednesday), when market prices of target species are lower would reduce the double of effort than one month of seasonal closure, and likely without subsidies. However, the loss by banning all Wednesdays (approx. 50 days) was higher in both ports than one month, but lower than an equivalent two months closure. M. Samy-Kamal was supported by a grant of the Spanish Agency for International Cooperation for Development (AECID) MAEC-AECID (Nº0000593564).

Relatively little scientific work has been done to assess the selectivity of square-mesh codends in the highly variable multi-species conditions in the Italian trawl fisheries. Therefore this study was initiated to investigate the effect of using square-mesh and larger diamond-mesh codends on size selectivity of deepwater red shrimp (Aristaeomorpha foliacea) and red mullet (Mullus barbatus), with possible implication in future management measures. Four different codends were used in the sea trials. When size selection estimates are applied for management issues it is not sufficient only to consider the mean size selection parameters. It also needs to consider the effect of between-haul variations in the selection process. In the current study, potential consequences of the between-haul variation on the selection curves have been considered by applying a pooled curve with a double bootstrap approach. The results attained in the present study indicate that the use of 40. mm square-mesh codend results in a 50% retention length (L50) similar to that of the 50. mm diamond-mesh codend, but with a steeper selection range (SR). For red mullet, both 50. mm diamond-mesh and 40. mm square-mesh codends lead to an L50 that is higher than the minimum landing size (MLS, 11. cm). Deepwater red shrimp is not subject to any MLS and may always be landed legally. However, large amounts of juveniles of deepwater red shrimp have been retained in all codends. Council Regulation (EC) No. 1967/2006 called for a discard reduction policy in waters under the jurisdiction of the European Union. As demonstrated in the current paper, to simultaneously improve the size selectivity of fish and shrimp species can be difficult due to large differences in their morphological characteristics, therefore it may question whether more sophisticated alternative of selective devices, such as grids or square-mesh panels, could be implemented in some Mediterranean fisheries. © 2014 Elsevier B.V.

A key assumption of many fish stock assessment models is that catchability is constant over time. We assume here that trends in catchability may occur through fishing power creeping. The tuning fleets, which are prone to fishing power development, may be identified using the Hybrid method. A range of catchability trends, including values derived from the Hybrid method, is then implemented to standardise the fishing effort of some tuning fleets used in the stock assessments performed by XSA (eXtended Survivors Analysis). Stocks being assessed are the North Sea cod, saithe, plaice and sole. The performances of the new and traditional XSA assessments are compared using criteria based on the precision of catchability estimates, stationarity of Log-catchability residuals and retrospective patterns relative to fishing mortality, spawning stock biomass and recruitment estimates. The performances of the North Sea cod, plaice and sole assessments could be enhanced by accounting for an overall annual increase in the catchability of some of the tuning fleets. No significant trends could be detected in the catchability of the tuning fleets relative to the assessment of the North Sea saithe. By contrast with the traditional assessment, the spawning biomass of cod is expected not to have increased between 1997 and 1998, while the fishing mortality of sole is expected to have increased over the same period., No disponible

A key assumption of many fish stock assessment models is that catchability is constant over time. We assume here that trends in catchability may occur through fishing power creeping. The tuning fleets, which are prone to fishing power development, may be identified using the "Hybrid" method. A range of catchability trends, including values derived from the "Hybrid" method, is then implemented to standardise the fishing effort of some tuning fleets used in the stock assessments performed by XSA (eXtended Survivors Analysis). Stocks being assessed are the North Sea cod, saithe, plaice and sole. The performances of the new and traditional XSA assessments are compared using criteria based on the precision of catchability estimates, stationarity of Log-catchability residuals and retrospective patterns relative to fishing mortality, spawning stock biomass and recruitment estimates. The performances of the North Sea cod, plaice and sole assessments could be enhanced by accounting for an overall annual increase in the catchability of some of the tuning fleets. No significant trends could be detected in the catchability of the tuning fleets relative to the assessment of the North Sea saithe. By contrast with the traditional assessment, the spawning biomass of cod is expected not to have increased between 1997 and 1998, while the fishing mortality of sole is expected to have increased over the same period.

To reduce the practice of discarding commercially fished organisms, several measures such as a discard ban and extra allowances on top of landings quotas (“catch quota”) have been proposed by the European Commission. However, for their development and successful implementation, an understanding of discard patterns on a European scale is needed. In this study, we present an inter-national synthesis of discard data collected on board commercial, towed-gear equipped vessels operating under six different national flags spanning from the Baltic to the Mediterranean Seas mainly between 2003 and 2008. We considered discarded species of commercial value such as Atlantic cod (Gadus morhua), haddock (Melanogrammus aeglefinus), European hake (Merluccius merluccius), and European plaice (Pleuronectes platessa). Comparisons of discard per unit effort rates expressed as numbers per hour of fishing revealed that in the Mediterranean Sea minimum size-regulated species such as hake are generally discarded in much lower numbers than elsewhere. For most species examined, variability in discard rates across regions was greater than across fisheries, suggesting that a region-by-region approach to discard reduction would be more relevant. The high uncertainty in discard rate estimates suggests that current sampling regimes should be either expanded or complemented by other data sources, if they are to be used for setting catch quotas., Sí

Fisheries bycatch is a key threat to cetacean species globally. Managing the impact requires an understanding of the conditions under which animals are caught and the sections of the population affected. We used observer data collected on an albacore tuna gillnet fishery in the northeast Atlantic, to assess operational and environmental factors contributing to bycatch of common and striped dolphins, using generalised linear models and model averaging. Life history demographics of the captured animals were also investigated. In both species, young males dominated the catch. The age ratio of common dolphins was significantly different from that estimated for the population in the region, based on life tables (G = 17.1, d.f. = 2, p = 0.002). Skewed age and sex ratios may reflect varying vulnerability to capture, through differences in behaviour or segregation in populations. Adult females constituted the second largest portion of the bycatch for both species, with potential consequences for population sustainability. Depth was the most important parameter influencing bycatch of both species and reflected what is known about common and striped dolphin habitat use in the region as the probability of catching common dolphins decreased, and striped dolphins increased, with increasing depth. Striped dolphin capture was similarly influenced by the extent to which operations were conducted in daylight, with the probability of capture increasing with increased operations in the pre-sunset and post-sunrise period, potentially driven by increased ability of observers to record animals during daylight operations, or by diurnal movements increasing contact with the fishery. Effort, based on net length and soak time, had little influence on the probability of capturing either species. Our results illustrate the importance of assessing the demographic of the animals captured during observer programmes and, perhaps more importantly, suggest that effort restrictions alone may not be sufficient to eradicate bycatch in areas where driftnets and small cetaceans co-occur.

Many marine fish stocks are overexploited and considerable overcapacity exists in fishing fleets worldwide. One of the reasons for the imbalance between resource availability and fishing capacity is technological development, which continuously increases the efficiency of the vessels—a mechanism referred to as “technological creep.” We review how the introduction of new and more efficient electronic equipment, gear design, engines, deck equipment, and catch-handling procedures influences the capture efficiency (catchability) of commercial fishing vessels. On average, we estimate that catchability increases by 3.2% per year due to technological developments, an increase often ignored in fisheries management. The documentation and quantification of technological creep improves the basis for successfully integrating the effects of technological development (and catchability changes) in fisheries management regulations and policies. Ways of counteracting the undesired effects of technological creep are discussed as are the potential management benefits from improved fishing technology. Specific suggestions are given on the selection, application, and tuning of fisheries management tools that can be used to improve the balance between harvesting capacity and resource availability.

Understanding the dynamics of a fishery is a key ingredient to successful fishery management. The objective of this study was to improve the understanding of the dynamics of the trawl demersal fishery that operates in San Matías Gulf (Patagonia, Argentina). This system offers an opportunity to explore different issues of fishery dynamics and management because it is a simple model with a few well-characterised active vessels and a stock of Argentine hake (Merluccius hubbsi) that seems to have been well preserved since the beginning of the fishery in 1970. This study combined different sources of information to analyse the seasonality of landings, the link between catch and landing profiles, and the association between sea surface temperature and the spatio-temporal variability in catch profiles. The monthly species composition of the catch fell into three fishing seasons, each with a distinct landing profile. During warm months, M. hubbsi dominated the catch, and bottom trawl activity was concentrated in a thermal frontal zone. In winter, the fishing activity was more disbursed over the surface of the gulf, and yields were minimal. From August to October, the landings increased rapidly due to the catch of Seriolella porosa, and the distribution of the fishing effort was partially concentrated in the northeastern area of the gulf. The seasonal pattern observed would be related to the resource availability and the commercial opportunities. These factors were significant in determining what, when, and where to fish in the trawl demersal fishery of San Matías Gulf. Fil: Romero, Maria Alejandra. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Instituto de Biologia Marina y Pesquera Almirante Storni; Argentina Fil: Ocampo Reinaldo, Matías. Universidad Nacional del Comahue. Instituto de Biologia Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Leibniz Centre for Tropical Marine Ecology; Alemania Fil: Williams, Gabriela Noemi. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentina Fil: Narvarte, Maite Andrea. Universidad Nacional del Comahue. Instituto de Biologia Marina y Pesquera Almirante Storni; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina Fil: Gagliardini, Domingo Antonio. Leibniz Centre for Tropical Marine Ecology; Alemania. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio(i); Argentina Fil: González, Raul Alberto Candido. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional del Comahue. Instituto de Biologia Marina y Pesquera Almirante Storni; Argentina

Surveys are often insufficient to accurately capture the distribution of a species in both space and time. Complementary to the use of research vessel data, platforms of opportunity can be a powerful strategy to monitor species distributions at high temporal and spatial resolution. In this study we use data from commercial fishing vessels, collecting - under the European Union data collection framework - biological data on all species that are caught and subsequently discarded. Using such discard data in combination with a systematic trawl survey, we model the spatial and temporal distribution of juvenile plaice (Pleuronectes platessa) in the central North Sea. There is a clear age-dependent difference between the commercial fishing vessel data and the research vessel data, with age 1 being the dominating age in the survey catches, while age 2 is the dominating age in the discards. The results show how immature plaice, slowly migrate from the nursery areas, westwards into the deeper regions of the North Sea. Also, the results show that during the study period, juvenile plaice gradually moved to deeper waters at an earlier age. Finally we discuss how the framework can be applied to similar opportunistic data to monitor seasonal and inter-annual migration of marine organisms, and to quantify how they may be influenced by biotic and abiotic gradients, such as temperature. (C) 2012 Elsevier B.V. All rights reserved.

North Sea cod Gadus morhua stock is outside safe biological limits, and total allowable catch (TAC) management has proved ineffective to rebuild the stock. The European Commission is considering the imposition of a discard ban to preserve vulnerable and economically important fish stocks. We explored the potential effects of a discard ban in mixed fisheries management using the French mixed fisheries in the Eastern English Channel as a model system. We examined in particular the performance of 2 different management scenarios: (1) individual quota management with a tolerance for discarding and (2) individual quota management in combination with a discard ban, using a dynamic state variable model. The model evaluates a time series of decisions taken by fishers to maximize profits within management constraints. Compliance to management was tested by applying an in-height varying fine for exceeding the quota. We then evaluated the consequences of individual cod quota in both scenarios with respect to over-quota discarding, spatial and temporal effort allocation and switching between metiers. Individual quota management without a discard ban hardly influenced fishers' behaviour as they could fully utilise cod quota and continue fishing other species while discarding cod. In contrast, a discard ban forced fishers to reallocate effort to areas and weeks in which cod catch is low, at the expense of lower revenue. In general, a restrictive policy for individual quota for cod needs to be combined with a discard ban and a high fine (>20 times the sale price) to reduce over-quota discarding.

This paper introduces a semiqualitative approach to analyse the joint dynamics of fleets and stocks in a multispecies, multifleet fishery. We ask whether changes in fleets affect resource dynamics and whether trends in resource influence fleet dynamics more than external drivers do. External drivers include vessel buyback, fuel price, and fish prices, as well as environmental fluctuations. Resource status is measured by abundance and length metrics; fleet capacity is measured by total horse power, and economic metrics such as profitability and earnings are examined as well. A maximum likelihood approach is used to identify the combined metric trends with the largest support in the data. The approach is applied to the French Bay of Biscay fisheries in 2000-2007. Combined-metric time trends suggest that decreases in fleet capacity did not result in decreasing fishing impacts; trends in stocks and fish prices were not the major drivers of changes in fleets either. Rather, the vessel buyback program might have been the main factor determining fleet dynamics over that period., Notre étude présente une approche semi-qualitative pour analyser la dynamique conjointe des flottilles et des stocks dans une pêcherie multi-spécifique et multi-flottille. Nous examinons si les changements dans les flottilles affectent la dynamique des stocks, et si les tendances des stocks influencent la dynamique des flottilles davantage que des facteurs externes. Ces facteurs incluent un programme de sortie de flotte, les prix du gasoil et du poisson, ainsi que les fluctuations environnementales. L’état des stocks est évalué par des métriques d’abondance et de longueur; la capacité des flottilles est mesurée par la puissance totale; des indicateurs économiques comme la rentabilité et les salaires sont aussi examinés. Les tendances combinées de ces métriques les mieux appuyées par les données sont identifiées par une méthode de maximum de vraisemblance. L’approche est appliquée aux flottilles françaises dans le golfe de Gascogne de 2000 à 2007. Les tendances temporelles combinées suggèrent que la diminution de capacité de la flotte ne s’est pas traduite par une réduction de l’impact de la pêche sur les ressources; les changements dans l’état des stocks et le prix du poisson n’étaient pas non plus les principaux facteurs des changements dans les flottilles. C’est plutôt le programme de sortie de flotte qui semble avoir été le facteur majeur de l’évolution des flottilles pendant cette période.

Discards of unwanted or undersized fish and other non-target species represent a significant proportion of global marine catches that enhance the negative impact of fishery, especially when using fishing tools with low selectivity as bottom trawl nets. In order to estimate both retained and discarded catch composition of the commercial trawl fisheries in the eastern Adriatic, we used scientific observer records during 2010 and 2011. A total of 49 fish species, 12 cephalopods and 7 crustaceans were recorded in the catches, of which 29 species were always discarded and 39 species were only partially retained (discarding practice was generally market-driven). During the investigation period, it was estimated that 76.5% of the total catch by number and 39.6% by weight were discarded. When focused only on the sampled fish species, 18 were always discarded with Seranus hepatus, Boops boops, Gadiculus argenteus, Lepidopus caudatus, Lesueurigobius friesii and Callionymus sp. being the most numerous among them. On the other hand, the most abundant commercial fish species that were only partially discarded were Merluccius merluccius, Trachurus sp., Lophius budegassa, Mullus barbatus, Lepidorhombus sp. and Micromesistius poutassou. Estimated percentages of discard for these species were as follows: for M. merluccius 49.2% by number and 12.4% by weight, for Trachurus sp. 41.2% by number and 12.6% by weight, for L. budegassa 56.5% by number and 5.9% by weight, for M. barbatus 5.7% by number and 2.8% by weight, for Lepidorhombus sp. 84.4% by number and 48.4% by weight, for M. poutassou 79.7% by number and 73.3% by weight. Catches of M. barbatus were almost always retained and small amounts of discard mainly referred to the individuals of TL bellow 11 cm (MLS for this species) and therefore of no commercial interest for the fishermen. On the contrary, M. poutassou was usually discarded and was retained only when the overall catch was low. For the remaining four species, although discard percentages by weight may be considered as low, it should be noted that discard percentages by number are quite high and are further emphasizing the significant impact of discards on the state of fish populations.

In this work we analysed the spatio-temporal variability of discards in the fishery of the deep-sea red shrimp Aristeus antennatus in the northwestern Mediterranean Sea. We sampled fishery discards in the fishing grounds of Palamós (the main harbour for this fishery on the Catalan margin), which are located in several areas of a submarine canyon. We found that the discard ratio in this fishery showed a marked seasonal variability, with a maximum in spring and a minimum in summer. Most of the discarded biomass (almost 96%) were of species with no commercial interest. Within these, the most represented group was elasmobranchs, making up to more than 50% of total discarded biomass. Our findings show that the landing obligation established by the EU will have a low impact in mitigating discards in this fishery, as the vast majority of discards are non-commercial species that are not specified in the regulation. Alternative management strategies, such as a temporary fishery closure in spring (when the discard ratio reaches its maximum), should be considered in order to preserve the vulnerable ecosystem hosted by the submarine canyon. En este estudio se analizó la variabilidad espacio-temporal de los descartes en la pesquería de la gamba roja de profundidad Aristeus antennatus en el mar Mediterráneo Noroccidental. Para ello se muestrearon las capturas obtenidas en los caladeros de Palamós (el mayor puerto para esta pesquería en Cataluña), que están localizados en diferentes áreas adyacentes a un cañón submarino. Nuestros resultados demuestran que la proporción de descartes en las capturas de esta pesquería presenta una marcada variabilidad estacional, con un máximo en primavera y un mínimo en verano. La mayoría de la biomasa de los descartes (casi el 96%) está constituida por especies sin ningún interés comercial. Entre éstas, el grupo más representado es el de los elasmobranquios, que constituye más del 50% de la biomasa total de los descartes. Nuestros resultados indican que la obligación de desembarcar las capturas establecida por la UE tendrá un impacto bajo en disminuir los descartes en esta pesquería, ya que la gran mayoría de los descartes está constituida por especies no comerciales que no están especificadas en la regulación. Medidas de gestión alternativas, como el establecimiento de una veda en primavera (cuando la proporción de descartes llega a su máximo) deberían considerarse para preservar el ecosistema vulnerable de este cañón submarino.

The Corumbau marine extractive reserve (MER) was the first MER specifically designed to protect coral reefs. Fishers and their families were directly dependent on extractive activities in the area. The objective of this research, was to study the biology of the sea bob shrimp Xiphopenaeus kroyeri (Heller, 1862), its fisheries aspects and evaluate the effectiveness of a bycatch reduce devices (BRD). Fish landings were daily monitored between Aug/04 and Dec/06. Shrimp samples landed (Jul/04 to Jan/07) were weekly analyzed. Monitored fisheries, in the ten main fishing grounds around the region (Jan/07 to Jan/09), were seasonally carried out. The BRD was tested (Feb/06 and Aug/06) in an experimental net, with a conded composed of a standard net (30mm mesh) and a squaremesh (50mm) front top panel (50x50cm) and compared with a net control. A total of 55.409 individuals were sampled. The CL50 found was 12.55 mm. Females reach larger sizes (CL = 38.59 mm), a higher longevity (tmax = 26 months) and had lower growth rate (kmonth = 0.17) than males (CL = 32.35 mm; tmax = 16 months and kmonth = 0.28). The sex ratio did not differ between females and males, suggesting that trawl fisheries in Corumbau MER act mainly in growth and mating areas, not in spawning locations. There was a higher female frequency in reproductive activity in the first semester, mainly related to a higher transparency, salinity and water temperature. Rare events of Tropical Water mass probably led to favorable spawning conditions, even in places near to the coast. Recruitment period was continuous with the main peak occurring in July/August. The highest juvenile abundance was associated with higher water turbidity and pH values. Trawl fishery in Corumbau MER is handmade, not going over an isobaths average of 15m. The departures are daily held, mainly focused in the morning, minimizing the need for fish cooling and reducing the operations cost. Fishing effort varied among the communities, being greatest in Corumbau, followed by Cumuruxatiba and then Caraíva. The fishing grounds use varied seasonally, often related to climatic conditions and water visibility. X. kroyeri was the most abundant penaeid (96.4%) in all communities landings, with high fishing performance in Corumbau. The higest X. kroyeri CPUEs occurred during the autumn and winter, showing a negative correlation with water visibility and temperatures, coinciding with species recruitment. Around 50% of the fisheries act on less than 15mm CL individuals size. Thus, fishing in that region, may be running in an inappropriate way to sustainable resource management. The white shrimp (L. schmitti) production was very low compared to other species, although it was present all year round, in the three communities. The pink shrimp (F. brasiliensis and F. paulensis) production was higher in Cumuruxatiba, where a clear seasonal pattern is observed. A low CPUE was registered during winter and gradually increasing over the years, with harvest peak occurring in fall. Shrimp captures were probably limited to species recruitment period. During the experiment for bycatch reduce us identified 93 fish taxa, 89 belonging to Actinopterygii Class and 3 to Chondrichthyes Class. The square mesh nets are effective in excluding bycatch without affecting the catch of sea bob shrimp. The behavior, body shape and swimming ability were crucial for fish escape success from the panel, favoring especially the larger ones. A difference in fish assemblage could be established between sampling periods, not changing the device efficiency. Besides, depth regardless, a positive effect of square mesh panel was observed. Thus, this device use is very promising tool due to its structural features, as well as having low cost, been easy to purchase and to install. Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES A RESEX Corumbau é uma Unidade de Conservação de uso direto, que abriga uma porção representativa do Banco dos Abrolhos, sendo que a maior parte dos extrativistas dedica-se à pesca. O objetivo deste trabalho foi estudar a biologia do camarão Xiphopenaeus kroyeri (Heller, 1862), os aspectos da sua pesca e testar a eficiência de um dispositivo de redução de captura da fauna acompanhante. Os desembarques pesqueiros foram monitorados diariamente entre ago/04 e dez/06. Amostras dos camarões desembarcados (jul/04 a jan/07) foram analisadas semanalmente. Arrastos monitorados nos dez principais pesqueiros da região (jan/07 a jan/09) foram realizados sazonalmente. O dispositivo de redução foi testado (fev/06 e ago/06) em uma rede experimental, com o ensacador de malha 30mm e com um painel (50x50cm) localizado na parte anterior superior, confeccionado com malha quadrada (50mm) e comparados com uma rede controle. O total de 55.409 indivíduos foi amostrado. O CC50 encontrado foi de 12,55mm. As fêmeas atingem tamanhos maiores (CC=38,59mm), uma longevidade mais alta (tmax=26 meses) e apresentam índice de crescimento menor (kmês=0,17) que os machos (CC=32,35mm; tmax=16 meses e kmês=0,28). A razão sexual não diferiu, sugerindo que as pescarias de arrastos na RESEX Corumbau atuam principalmente em áreas de crescimento e acasalamento e não de desova. Verificou-se uma maior freqüência de fêmeas em atividade reprodutiva no primeiro semestre, relacionada principalmente com uma maior transparência, salinidade e temperatura da água. Eventos raros de entrada da massa de Água Tropical provavelmente propiciaram condições favoráveis à desova, mesmo em locais próximos a costa. O período de recrutamento foi contínuo, com o pico principal ocorrendo em julho/agosto. A maior abundância de jovens ocorreu associada a maiores valores de turbidez e pH da água. A pesca de arrasto na RESEX Corumbau é artesanal, não ultrapassando a isóbata média de 15m. As saídas são realizadas diariamente, concentrando-se principalmente pela manhã, minimizando a necessidade de resfriamento do pescado e diminuindo o custo das operações. O esforço de pesca variou entre as comunidades, sendo maior em Corumbau seguido por Cumuruxatiba e depois Caraíva. A utilização dos pesqueiros variou sazonalmente, sendo freqüentemente relacionada com as condições climáticas e com a visibilidade da água. X. kroyeri foi o peneídeo mais abundante (96,4%) nos desembarques de todas as comunidades, com o rendimento pesqueiro médio mais elevado em Corumbau. As maiores CPUEs de X. kroyeri ocorreram no durante o outono e o inverno, e apresentando uma relação negativa com a visibilidade e a temperatura da água e coincidindo com o período de recrutamento da espécie. Cerca de 50% das pescarias atuam sobre indivíduos com tamanho inferior à 15mm de CC. Assim, a pesca na região pode estar sendo executada de maneira inadequada ao manejo sustentável deste recurso. A produção do camarão VG (L. schmitti) foi muito baixa em relação às outras espécies, embora o mesmo esteja presente em todas as estações do ano, nas três comunidades. A produção de camarão rosa (F. brasiliensis e F. paulensis) foi maior em Cumuruxatiba, onde se pode observar uma nítida variação sazonal, com a CPUE baixa durante o inverno e aumentando gradativamente ao longo do ano, com o pico da safra ocorrendo no outono. As capturas do camarão rosa, provavelmente, foram limitadas ao período de recrutamento da espécie. Durante o experimento de redução de fauna acompanhante foram identificadas 93 espécies de peixes, sendo 89 pertencentes a Classe Actinopterygii e 3 a Classe Chondrichthyes. Foi possível verificar que as redes com o painel de malha quadrada são eficientes na exclusão da ictiofauna acompanhante, sem alterar as capturas de camarões sete-barbas. O comportamento, o formato do corpo e a capacidade de natação influenciaram a capacidade dos peixes para escaparem pelo painel, favorecendo, principalmente, os indivíduos de maior porte. Foi possível identificar diferenças nas assembléias de peixes entre os dois períodos analisados, sem alterações na eficiência do dispositivo. Além disso, independente da profundidade, o efeito positivo do painel de malha quadrada foi observado. Desta forma, a utilização desse dispositivo é bastante promissora devido à suas características estruturais, além de possuir baixo custo e ser de fácil aquisição e instalação.

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:23:57Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:41:03Z : No. of bitstreams: 1 2-s2.0-68349139677.pdf: 225328 bytes, checksum: cb282d6b711f762ea066c81fab5691fc (MD5) Made available in DSpace on 2014-05-27T11:23:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2009-08-14 One specimen of the lophiid white anglerfish, Lophiodes beroe was collected for the second time in Brazilian waters, which far extends the limit distribution of the species to southeastern region (25°00'08). Acervo Zoológico da UNISANTA (AZUSC) Rua Oswaldo Cruz, 266 - Bloco B - 3 andar/sala B-31A, CEP:11045-907, Santos SP Laboratório de Elasmobrânquios, UNESP, Praça Infante Dom Henrique s/n, CEP: 11330-900 São Vicente SP Laboratório de Elasmobrânquios, UNESP, Praça Infante Dom Henrique s/n, CEP: 11330-900 São Vicente SP

The aim of the present paper is to study the relationships between some climatic indices and parental stock, recruitment and accessibility to trawl fishery of hake (Merluccius merluccius) and red shrimp (Aristeus antennatus) off Balearic Islands (western Mediterranean). Available annual catch per unit effort, recruitment and spawning stock biomass have been used as biological data. As environmental data, the meso-scale IDEA index and the large-scale North Atlantic Oscillation (NAO) and Mediterranean Oscillation (MO) indices have been used. To analyze possible links between these indices with the population dynamics of demersal resources, two non-linear approaches have been applied: (i) stock-recruitment relationships from Ricker and Beverton-Holt models, by sequentially incorporating environment factors; (ii) generalized additive modelling, both classical general and threshold non-additive models were considered. The latter simulate an abrupt change in explicative variables across different phases (time periods or climatic index values). The results have shown that two oceanographic scenarios around the Balearic Islands, associated with macro and meso-scale climate regimes, can influence the population dynamics of hake and red shrimp. This is especially true for recruitment, which seems to be enhanced during low NAO and IDEA indices periods. During these periods, colder-than-normal winters generate high amounts of cold Western Mediterranean Intermediate Waters (WIW) in the Gulf of Lions, which flow southwards and reach the Balearic Islands channels in spring, increasing the productivity in the area. This oceanographic scenario could also be favourable to the distribution of hake on the fishing grounds where the trawl fleet targets this species, increasing its accessibility to the fishery. Both spawning stock and abundance of red shrimp seems to be also enhanced by high MO index periods, which could reflect the increased presence of the saline and warm Levantine Intermediate Waters (LIW) in the study area, extending over the fishing grounds of this species. The proposed interactions can be useful to assess and manage these important demersal resources. © 2007 Elsevier B.V. All rights reserved., The IDEA project has been funded by the Spanish Ministry of Education and Science (Plan Nacional I+D+i 2000-2003, REN2002-04535-C01-02/MAR)

Gli effetti del divieto di strascico nel Golfo di Castellammsare sono analizzati in funzione del livello di applicazione del divieto. Vengono descritti i pro e contro del divieto dal punto di vista dei pescatori a strascico che gravitano attorno all'area vietata.

Fisheries bycatch often affects particular size classes of turtles. Because of the late age at maturity for loggerhead turtles, the reproductive value of individual small juveniles, large juveniles and adults may vary by orders of magnitude. The reproductive value, which is based on age, provides a relative measure of value for individuals, thereby allowing us to estimate the effects of different stressors based on the number of animals killed. Using reproductive value as a comparative index, we assessed the relative impact of trawl and gillnet fisheries operating in the northern Adriatic Sea (Croatia and Slovenia) on loggerhead populations. The northern Adriatic host one of the most important developmental habitats for the species in the Mediterranean, and, at the same time, is one of the heaviest fished areas, resulting in high bycatch rates. We tested several scenarios for bycatch and mortality in both fisheries. Despite high bycatch rates, bottom trawl fisheries result in direct death of fewer loggerheads (267-355 vs. 361-2217 in gill nets), but affect individuals that are older than average and hence have higher reproductive values. Because of data limitations for vital rates and bycatch estimates, we looked at a distribution of potential impact for each fishery. Lessons learned include the need for relative, rather than absolute, impact assessment because of the sensitivity of adult reproductive value to parameters such as clutch frequency, sex ratio and remigration interval. We anticipate that our analysis will help managers prioritize needs for regulation and mitigation among different fisheries.

KARATAŞ (ADANA) AÇIKLARINDA D P TROLLER YLE AVLANANEKONOM K POTANS YELE SAH P TÜRLER N NCELENMESÖzet: Bu çalışma, 2002-2003 balıkçılık sezonunda kuzeydoğu Akdeniz'in Türkiyekıyılarında yer alan Karataş açıklarında gerçekleştirilmiştir. Dip trolü çekimleri aylıkperiyotlarla 0-20m, 20-50m ve 50-100m derinlik katmanlarından birer saatlik olmaküzere yapılmıştır. Örnekleme dönemi boyunca toplam olarak 90 balık, 15 kabukluve 5 kafadan bacaklı türüne rastlanmıştır. Toplam 24 adet trol çekimi sonucunda631403.89g materyal elde edilmiş olup; ortalama CPUE değeri 26308.5g saat-1olarak hesaplanmıştır. Derinlik katmanları itibariyle en düşük ve en yüksek CPUEdeğerlerine 13544.80g saat-1 ve 33319.80g saat-1 sırasıyla 50-100m ve 20-50mderinlik katmanlarında rastlanmıştır. Aylar itibariyle en yüksek CPUE değerine eylülayında (66756.30g saat-1) rastlanmış olup; bu değer eylül ayında itibaren süreklidüşüş göstererek, en düşük değer 12478,50g saat-1 ile mart ayından elde edilmiştir.Toplam av içerisinde balıkların %79.10'luk bir değerle birinci sırada yer aldığı;bunu %13.73 ile kabukluların ve %7.17'lik bir değerle de kafadan bacaklılarınizlediği belirlenmiştir. Ayrıca elde edilen toplam biyokütlenin %38.68'ini ıskartatürlerin oluşturduğu saptanmıştır. Toplam avın tür sayısı olarak %18.90'ının vebiyokütle olarak ise, %26.66'sının lesepsiyen balıklardan oluştuğu tespit edilmiştir.Ana av içerisinde %19.48'lik bir değerle Mullus barbatus'un ilk sırada yer aldığı;bunu sırasıyla Charybdis longicollis (%15.98) ve Saurida undosquamis'in (%15.56)izlediği belirlenmiştir. Bazı türler için belirlenmiş olan seçicilik parametrelerisonucunda bölgedeki türlerin aşırı avcılık baskısı altında olduğu sonucunavarılmıştır. Ayrıca Mullus barbatus ve Upeneus pori ile ilgili yapılandeğerlendirmeler sonucu balıkçılık sezonunun kasım ayında açılmasının bölgebalıkçılığına yararlar sağlayacağı sonucuna varılmıştır.Anahtar Kelimeler: Kuzeydoğu Akdeniz, Trol Balıkçılığı, Lessepsiyen, Iskarta STUDY ON THE POTANCIALLY ECONOMICAL IMPORTANT SPECIESTRAWLED FROM KARATAŞ (ADANA) COASTSAbstract: This study was carried out during 2002-2003 fishing season off theKaratas located along the Northeastern Mediterranean coast of Turkey. The deeptrawl net was operated by monthly sampling interval with one-hour haul duration in0-20m, 20-50m and 50-100m depth ranges. During the study period, on the basis ofspecies; a total of 90 fishes, five cephalopods, and 15 crustaceans were caught. Totalweight of marine organisms obtained from 24 deep trawl operations were631403.89g and its mean CPUE value was calculated as 26308.5±18954.2g hour-1.Minimum and maximum CPUE values for 50-100m and 20-50m depth ranges weredetermined 13544.80g hour-1 and 33319.80g hour-1 respectively. During the studyperiod the maximum CPUE value was obtained in September (66756.30g hour-1)and this value decreased continuously to 12478.50g hour-1 in March. Fishesrepresented the major proportion with respect to the total catch (79.10%), followedby crustaceans (13.73%) and cephalopods (7.17%). In addition, on average 37.9% ofthe total catch was discarded. Number of lessepsian fish species consisted of %18.9of total fish species, and lessepsian proportion of total fish biomass were estimatedas 26.66%. In the main catch, Mullus barbatus was the most abundant species withthe proportion of %19.48 and followed by Charybdis longicollis (%15.98) andSaurida undosquamis (%15.56). Selectivity parameters for some fish speciesindicated that fish populations inhabiting in the study area have been under fishingpressure. In addition, some analysis were conducted by using Mullus barbatus andUpeneus pori, and found that, if the fishing season opens in November, it would bebeneficial for both regional fish populations and fisheries.Key Words: Northeastern Mediterranean, Trawl Fishery, Lessepsian, Discard 160

Effort management has been proposed as an alternative for quota management in mixed demersal fisheries. It requires a metric to estimate the fishing mortality imposed by a given quantity of nominal fishing effort. Here, we estimate the partial fishing mortality rate imposed by one unit of fishing effort (Fpue) during individual fishing trips and explore the usefulness of this indicator for managing North Sea beam trawlers >300 hp targeting sole (Solea solea) and plaice (Pleuronectes platessa). Fpue is positively related to vessel engine power, and increased annually by 2.8% (sole) and 1.6% (plaice). The positive trend was due to an increase in skipper skills and investment in auxiliary equipment, the replacement of old vessels by new ones and, to a lesser extent, to upgrade engines. The average Fpue imposed per day at sea by a 2000 hp beam trawler was estimated to be 1.0 × 10−5 (sole) and 0.6 × 10−5 (plaice), and it showed substantial seasonal and spatial variations. The Fpue of sole and plaice were negatively related in summer and showed no relationship in winter. The existence of predictive seasonal and spatial patterns in Fpue opens up the possibility of fine-tuning management by directed effort restrictions and uncoupling management of plaice and sole.

The box crabs, genus Calappa, are important crab species landed by the industrial trawl fleet in Venezuela. These crabs have a wide distribution in the country, from the Gulf of Venezuela to the Orinoco River, but major landings take place in such gulf, near Margarita Island and northern Sucre State. Average annual landing in the eastern region was 69 t during 1970-2001, with a maximum of 221 t. For this study a sample of 2 398 box crabs was collected by observers on board of industrial trawl vessels, which operated in eastern Venezuela from 1994 to 2000. Three species were found in the landings, Calappa sulcata and C. flammea, each represented 47% of the sample, and C. nítida, which accounted for 5% of the sample. Sex ratio was strongly biased towards males in C. sulcata (2.8:1) and in C. flammea (1.9:1), while it was only slightly biased in C. nitida (1.4:1). Due to its large size, C. sulcata is of great commercial interest, with average weight 290 g and a maximum weight of 720 g; C. flammea showed an average weight of 140 g and a maximum weight of 418 g, while C. nitida is the smallest species, with average weight 46 g and maximum weight not beyond 113 g. Box crabs were captured by day and night in similar proportions, and were found in a wide depth range, from a few meters to 126 m deep; however, the largest captures were obtained in the interval 38 - 54 m. Regressions between weight of chelae and total weight were linear, and significantly different between sexes. The relation between total weight and carapace width was allometric, with a power exponent ca. three in C. sulcata, and less than three in C. flamea and C. nítida. Females of C. sulcata and C. nitida showed power exponents significantly smaller than males. Since claws are removed from the animal to be commercialized, while the rest of the animal is returned alive to the sea, for practical purposes a common equation among species and sexes to convert claws weight into total body weight is: total weight = 3 x claws weight. The relationship between catch per unit of effort (CPUE) and effort did not show a significantly decreasing trend, but landings follow the effort trend, with a decreasing tendency in recent years. No mature females were found in any of the three species, thus there could be reproductive migrations towards deeper waters from October to January, when abundance of crabs is lower in the study area. It is recommended that the practice of exploiting only one claw, returning the rest of the animal alive to the sea, should be promoted among fishers, while the removal of claws from female crabs should be avoided Los cangrejos moros, del género Calappa, constituyen las principales especies de cangrejos desembarcados por la flota arrastrera industrial en Venezuela. Su distribución es amplia en el país, desde el Golfo de Venezuela hasta el delta del Río Orinoco, pero las mayores capturas provienen de dicho golfo, los alrededores de la Isla de Margarita y norte del estado Sucre. Las capturas en la región oriental alcanzaron 221 t por año, con un promedio de 69 t en el período 1970-2001. Para este estudio se procesó una muestra de 2 398 cangrejos moros recolectada por observadores científicos a bordo de las embarcaciones de arrastre industrial que operaron en el oriente del país entre 1994 y 2000. Tres especies componen las capturas, Calappa sulcata y C. flammea, ambas en proporción de 47%, y C. nítida, que representó 5% de la muestra. La proporción de sexos estuvo fuertemente sesgada hacia los machos en C. sulcata (2,8:1) y en C. flammea (1,9:1), y ligeramente sesgada en C. nitida (1,4:1). Calappa sulcata es la especie con mayor interés comercial para la flota, alcanzando un peso promedio de 290 g y máximo de 720 g; C. flammea alcanzó un peso promedio de 140 g y máximo de 418 g, mientras que el peso promedio de C. nitida fue 46 g y su peso máximo no superó los 113 g. Los cangrejos moros son capturados de noche y de día en similar proporción en la región oriental. Aunque la distribución batimétrica de estas especies es amplia, desde pocos metros a 126 m de profundidad, las mayores capturas tuvieron lugar entre 38 y 54 m. Las relaciones entre el peso de las quelas y el peso total fueron lineales y difirieron significativamente entre sexos. La relación entre el peso total y el ancho del caparazón fue alométrica, con exponente ca. 3 en C. sulcata, y menor que 3 en C. flamea y C. nítida. Las hembras de C. sulcata y C. nitida presentaron exponentes significativamente menores que los machos. Motivado a que las quelas son separadas a bordo para ser comercializadas, mientras que el ejemplar vivo es devuelto al mar, para fines prácticos una relación común para las tres especies, que permitiría convertir el peso de las quelas a peso total del ejemplar sería: Peso total = 3 x peso quelas. No se observa una tendencia descendente significativa en la relación entre las capturas por unidad de esfuerzo y el esfuerzo. La variación de las capturas tiende a seguir la del esfuerzo de pesca, con una tendencia descendente de ambos parámetros en los últimos años. No se encontraron hembras ovadas en las tres especies, por lo que pudieran ocurrir migraciones reproductivas hacia aguas más profundas durante los meses de octubre a enero, cuando la abundancia de los cangrejos es menor en el área de estudio. Se recomienda que la práctica de extraer una sola quela, devolviendo el resto del animal vivo al mar, debe promoverse entre los pescadores, mientras que debería evitarse la extracción de quelas en las hembras

Submitted by Vitor Silverio Rodrigues (vitorsrodrigues@reitoria.unesp.br) on 2014-05-27T11:20:36Z No. of bitstreams: 0Bitstream added on 2014-05-27T14:33:23Z : No. of bitstreams: 1 2-s2.0-23744486183.pdf: 280832 bytes, checksum: e5063a250882b4e115de7cbd61c8e187 (MD5) Made available in DSpace on 2014-05-27T11:20:36Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-01-01 Monthly collections of fishes using a trawl net were carried out from August 1996 to December 1997 with the objective of evaluating the composition and diversity of fish species in the littoral area of the transition zone between Veados Stream and Jurumirim Dam (Upper Paranapanema River, São Paulo State). Diversity and similarity indices of ichthyofauna at the sites were determined and correlated with abiotic factors such as dissolved oxygen, temperature, pluviometric precipitation and hydrological level. Twenty-six (26) fish species (the majority small-sized) of the family Characidae (Tetragonopterinae and Cheirodontinae) were registered. Representatives of the orders Siluformes, Gymnotiformes, Perciformes and Synbranchiformes occurred in lower abundance. Significant differences were found in the site diversity indices, but not in the abiotic factors. Significant correlations between the abundance of the ichthyofauna and the variations in the abiotic factors were not detected. The presence of fish larvae in the samples indicates the importance of the transition zone as a reproduction area of the fish species registered in this study. Instituto de Biociências Departamento de Morfologia Universidade Estadual Paulista (Unesp), Distrito Rubião Jr. s/n, 18618-000, Botucatu, São Paulo Instituto de Biociências Departamento de Morfologia Universidade Estadual Paulista (Unesp), Distrito Rubião Jr. s/n, 18618-000, Botucatu, São Paulo